bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct observation of room-temperature out-of-plane ferroelectricity and tunneling electroresistance at the two-dimensional limit
Authors: Wang H. , Liu Z. R. , Yoong H. Y. , Paudel T. R. , Xiao J. X. , Guo R. , Lin W. N. , Yang P. , Wang J. , Chow G. M. , Venkatesan T. , Tsymbal E. Y. , Tian H. , Chen J. S. 
Published: August 2018

AbstractOut-of-plane ferroelectricity with a high transition temperature in nanometer-scale films is required to miniaturize electronic devices. Direct visualization of stable ferroelectric polarization and its switching behavior in atomically thick films is critical for achieving this goal. Here, ferroelectric order at room temperature in the two-dimensional limit is demonstrated in tetragonal BiFeO3 ultrathin films. Using aberration-corrected scanning transmission electron microscopy, we directly observed robust out-of-plane spontaneous polarization in one-unit-cell-thick BiFeO3 films. High-resolution piezoresponse force microscopy measurements show that the polarization is stable and switchable, whereas a tunneling electroresistance effect of up to 370% is achieved in BiFeO3 films. Based on first-principles calculations and Kelvin probe force microscopy measurements, we explain the mechanism of polarization stabilization by the ionic displacements in oxide electrode and the surface charges. Our results indicate that critical thickness for ferroelectricity in the BiFeO3 film is virtually absent, making it a promising candidate for high-density nonvolatile memories.
Layer specific observation of slow thermal equilibration in ultrathin metallic nanostructures by femtosecond X-ray diffraction
Authors: Pudell J. , Maznev A. A. , Herzog M. , Kronseder M. , Back C. H. , Malinowski G. , von Reppert A. , Bargheer M. 
Published: August 2018

AbstractUltrafast heat transport in nanoscale metal multilayers is of great interest in the context of optically induced demagnetization, remagnetization and switching. If the penetration depth of light exceeds the bilayer thickness, layer-specific information is unavailable from optical probes. Femtosecond diffraction experiments provide unique experimental access to heat transport over single digit nanometer distances. Here, we investigate the structural response and the energy flow in the ultrathin double-layer system: gold on ferromagnetic nickel. Even though the excitation pulse is incident from the Au side, we observe a very rapid heating of the Ni lattice, whereas the Au lattice initially remains cold. The subsequent heat transfer from Ni to the Au lattice is found to be two orders of magnitude slower than predicted by the conventional heat equation and much slower than electron–phonon coupling times in Au. We present a simplified model calculation highlighting the relevant thermophysical quantities.
Deficient humoral responses and disrupted B-cell immunity are associated with fatal SFTSV infection
Authors: Song Peixin , Zheng Nan , Liu Yong , Tian Chen , Wu Xilin , Ma Xiaohua , Chen Deyan , Zou Xue , Wang Guiyang , Wang Huanru , Zhang Yongyang , Lu Sufang , Wu Chao , Wu Zhiwei 
Published: August 2018

AbstractSevere Fever with Thrombocytopenia Syndrome (SFTS), an emerging infectious disease caused by a novel phlebovirus, is associated with high fatality. Therapeutic interventions are lacking and disease pathogenesis is yet to be fully elucidated. The anti-viral immune response has been reported, but humoral involvement in viral pathogenesis is poorly understood. Here we show defective serological responses to SFTSV is associated with disease fatality and a combination of B-cell and T-cell impairment contribute to disruption of anti-viral immunity. The serological profile in deceased patients is characterized by absence of specific IgG to viral nucleocapsid and glycoprotein due to failure of B-cell class switching. Expansion and impairment of antibody secretion is a signature of fatal SFTSV infection. Apoptosis of monocytes in the early stage of infection diminishes antigen-presentation by dendritic cells, impedes differentiation and function of T follicular helper cells, and contributes to failure of the virus-specific humoral response.
Single-cell analysis reveals that stochasticity and paracrine signaling control interferon-alpha production by plasmacytoid dendritic cells
Authors: Wimmers Florian , Subedi Nikita , van Buuringen Nicole , Heister Daan , Vivié Judith , Beeren-Reinieren Inge , Woestenenk Rob , Dolstra Harry , Piruska Aigars , Jacobs Joannes F. M. , van Oudenaarden Alexander , Figdor Carl G. , Huck Wilhelm T. S. , de Vries I. Jolanda M. , Tel Jurjen 
Published: August 2018

AbstractType I interferon (IFN) is a key driver of immunity to infections and cancer. Plasmacytoid dendritic cells (pDCs) are uniquely equipped to produce large quantities of type I IFN but the mechanisms that control this process are poorly understood. Here we report on a droplet-based microfluidic platform to investigate type I IFN production in human pDCs at the single-cell level. We show that type I IFN but not TNFα production is limited to a small subpopulation of individually stimulated pDCs and controlled by stochastic gene regulation. Combining single-cell cytokine analysis with single-cell RNA-seq profiling reveals no evidence for a pre-existing subset of type I IFN-producing pDCs. By modulating the droplet microenvironment, we demonstrate that vigorous pDC population responses are driven by a type I IFN amplification loop. Our study highlights the significance of stochastic gene regulation and suggests strategies to dissect the characteristics of immune responses at the single-cell level.
BCL11A interacts with SOX2 to control the expression of epigenetic regulators in lung squamous carcinoma
Authors: Lazarus Kyren A. , Hadi Fazal , Zambon Elisabetta , Bach Karsten , Santolla Maria-Francesca , Watson Julie K. , Correia Lucia L. , Das Madhumita , Ugur Rosemary , Pensa Sara , Becker Lukas , Campos Lia S. , Ladds Graham , Liu Pentao , Evan Gerard I. , McCaughan Frank M. , Le Quesne John , Lee Joo-Hyeon , Calado Dinis , Khaled Walid T. 
Published: August 2018

AbstractPatients diagnosed with lung squamous cell carcinoma (LUSC) have limited targeted therapies. We report here the identification and characterisation of BCL11A, as a LUSC oncogene. Analysis of cancer genomics datasets revealed BCL11A to be upregulated in LUSC but not in lung adenocarcinoma (LUAD). Experimentally we demonstrate that non-physiological levels of BCL11A in vitro and in vivo promote squamous-like phenotypes, while its knockdown abolishes xenograft tumour formation. At the molecular level we found that BCL11A is transcriptionally regulated by SOX2 and is required for its oncogenic functions. Furthermore, we show that BCL11A and SOX2 regulate the expression of several transcription factors, including SETD8. We demonstrate that shRNA-mediated or pharmacological inhibition of SETD8 selectively inhibits LUSC growth. Collectively, our study indicates that BCL11A is integral to LUSC pathology and highlights the disruption of the BCL11A–SOX2 transcriptional programme as a novel candidate for drug development.
Room-temperature mechanocaloric effects in lithium-based superionic materials
Authors: Sagotra Arun K. , Chu Dewei , Cazorla Claudio 
Published: August 2018

AbstractMechanocaloric materials undergo sizable temperature changes during stress-induced phase transformations and hence are highly sought after for solid-state cooling applications. Most known mechanocaloric materials, however, operate at non-ambient temperatures and involve first-order structural transitions that pose practical cyclability issues. Here, we demonstrate large room-temperature mechanocaloric effects in the absence of any structural phase transformation in the fast-ion conductor Li3N (|ΔS| ~ 25 J K−1 kg−1 and |ΔT| ~ 5 K). Depending on whether the applied stress is hydrostatic or uniaxial the resulting caloric effect is either direct (ΔT > 0) or inverse (ΔT < 0). The dual caloric response of Li3N is due exclusively to stress-induced variations on its ionic conductivity, which entail large entropy and volume changes that are fully reversible. Our work should motivate the search of large and dual mechanocaloric effects in a wide variety of superionic materials already employed in electrochemical devices.
LTR retrotransposons transcribed in oocytes drive species-specific and heritable changes in DNA methylation
Authors: Brind’Amour Julie , Kobayashi Hisato , Richard Albert Julien , Shirane Kenjiro , Sakashita Akihiko , Kamio Asuka , Bogutz Aaron , Koike Tasuku , Karimi Mohammad M. , Lefebvre Louis , Kono Tomohiro , Lorincz Matthew C. 
Published: August 2018

AbstractDe novo DNA methylation (DNAme) during mouse oogenesis occurs within transcribed regions enriched for H3K36me3. As many oocyte transcripts originate in long terminal repeats (LTRs), which are heterogeneous even between closely related mammals, we examined whether species-specific LTR-initiated transcription units (LITs) shape the oocyte methylome. Here we identify thousands of syntenic regions in mouse, rat, and human that show divergent DNAme associated with private LITs, many of which initiate in lineage-specific LTR retrotransposons. Furthermore, CpG island (CGI) promoters methylated in mouse and/or rat, but not human oocytes, are embedded within rodent-specific LITs and vice versa. Notably, at a subset of such CGI promoters, DNAme persists on the maternal genome in fertilized and parthenogenetic mouse blastocysts or in human placenta, indicative of species-specific epigenetic inheritance. Polymorphic LITs are also responsible for disparate DNAme at promoter CGIs in distantly related mouse strains, revealing that LITs also promote intra-species divergence in CGI DNAme.
Epigenetic regulation of the circadian gene Per1 contributes to age-related changes in hippocampal memory
Authors: Kwapis Janine L. , Alaghband Yasaman , Kramár Enikö A. , López Alberto J. , Vogel Ciernia Annie , White André O. , Shu Guanhua , Rhee Diane , Michael Christina M. , Montellier Emilie , Liu Yu , Magnan Christophe N. , Chen Siwei , Sassone-Corsi Paolo , Baldi Pierre , Matheos Dina P. , Wood Marcelo A. 
Published: August 2018

AbstractAging is accompanied by impairments in both circadian rhythmicity and long-term memory. Although it is clear that memory performance is affected by circadian cycling, it is unknown whether age-related disruption of the circadian clock causes impaired hippocampal memory. Here, we show that the repressive histone deacetylase HDAC3 restricts long-term memory, synaptic plasticity, and experience-induced expression of the circadian genePer1in the aging hippocampus without affecting rhythmic circadian activity patterns. We also demonstrate that hippocampalPer1is critical for long-term memory formation. Together, our data challenge the traditional idea that alterations in the core circadian clock drive circadian-related changes in memory formation and instead argue for a more autonomous role for circadian clock gene function in hippocampal cells to gate the likelihood of long-term memory formation.
Unraveling exciton–phonon coupling in individual FAPbI3 nanocrystals emitting near-infrared single photons
Authors: Fu Ming , Tamarat Philippe , Trebbia Jean-Baptiste , Bodnarchuk Maryna I. , Kovalenko Maksym V. , Even Jacky , Lounis Brahim 
Published: August 2018

AbstractFormamidinium lead iodide (FAPbI3) exhibits the narrowest bandgap energy among lead halide perovskites, thus playing a pivotal role for the development of photovoltaics and near-infrared classical or quantum light sources. Here, we unveil the fundamental properties of FAPbI3 by spectroscopic investigations of nanocrystals of this material at the single-particle level. We show that these nanocrystals deliver near-infrared single photons suitable for quantum communication. Moreover, the low temperature photoluminescence spectra of FAPbI3 nanocrystals reveal the optical phonon modes responsible for the emission line broadening with temperature and a vanishing exciton–acoustic phonon interaction in these soft materials. The photoluminescence decays are governed by thermal mixing between fine structure states, with a two-optical phonon Raman scattering process. These results point to a strong Frölich interaction and to a phonon glass character that weakens the interactions of charge carriers with acoustic phonons and thus impacts their relaxation and mobility in these perovskites.
Photon antibunching control in a quantum dot and metallic nanoparticle hybrid system with non-Markovian dynamics
Authors: Moradi T. , Harouni M. Bagheri , Naderi M. H. 
Published: August 2018

AbstractPhoton-number statistics of the emitted photons from a quantum dot placed in the vicinity of a metallic nanoparticle driven by a laser in the non-Markovian regime is investigated theoretically. In the model scheme, the quantum dot is considered as an InAs three-level system in L-type configuration with two transition channels. We aim to introduce the hybrid system as a nonclassical photon source and control the antibunching behavior of the emitted photons by the geometrical as well as the physical parameters of the hybrid system. Our approach is based on the classical Green’s function technique and time convolution master equation. The results reveal that the emitted photons from the hybrid system under consideration are antibunched and energy is exchanged between the QD and nanoshell. By increasing the QD-MNP separation distance, the detuning frequency between the QD transitions and surface plasmon modes, and the Rabi frequency the antibunching time increases while the backaction of the reservoir on the QD decreases. To sum up, we conclude that the studied system has the potential to be a highly controllable single-photon source.
Screening for diabetes with HbA1c: Test performance of HbA1c compared to fasting plasma glucose among Chinese, Malay and Indian community residents in Singapore
Authors: Lim Wei-Yen , Ma Stefan , Heng Derrick , Tai E. Shyong , Khoo Chin Meng , Loh Tze Ping 
Published: August 2018

AbstractThe prevalence of diabetes in Singapore is high. Screening to facilitate early detection and intervention has been shown to be cost-effective. Current clinical practice guidelines in Singapore recommend screening with fasting plasma glucose (FPG), followed by an oral glucose tolerance test (OGTT) in those with FPG 6.1-6.9 mmol/L. Glycated haemoglobin A1c (HbA1c) has robust stability at ambient temperature, and can be performed on non-fasted capillary blood samples, making it an attractive potential alternative for screening. However, limitations of HbA1c include differential performance in different races, and its performance as a screening test has not been well characterized in Asian populations. This study compares HbA1c and FPG as diabetes screening modalities in 3540 community-dwelling Singapore residents of Chinese, Malay and Indian race to detect diabetes mellitus diagnosed based on blood glucose (FPG ≥ 7.0 mmol/L, 2 hr OGTT ≥ 11.1 mmol/L). The area under the receiver-operating-characteristic curve (AUC) was higher for FPG compared to HbA1c in the overall population and age, race and age-race strata, but these differences were not statistically significant. HbA1c > = 7.0% identified 95% of individuals with diabetes mellitus, and the remainder had impaired glucose tolerance (IGT). HbA1c cut-off at 6.1% had better sensitivity (0.825) to FPG at 6.1 mmol/L. The positive predictive value of HbA1c at 6.1% was 40–50% in different age-race combinations with a negative predictive value of about 98%. If follow-up screening with FPG is used, a lower cut-off at 5.6 mmol/L is appropriate in identifying people with pre-diabetes, as about 85% of people with HbA1c 6.1–6.9% and FPG 5.6–6.9 mmol/L had IFG/IGT or diabetes in the study sample. HbA1c is an appropriate alternative to FPG as a first-step screening test, and the combination of Hba1c > = 6.1% and FPG > = 5.6 mmol/L would improve the identification of individuals with diabetes mellitus and prediabetes.
An Intermediate Incubation Period and Primitive Brooding in a Theropod Dinosaur
Authors: Varricchio David J. , Kundrát Martin , Hogan Jason 
Published: August 2018

AbstractNon-avian dinosaurs such as oviraptorosaurs and troodontids share several important reproductive characters with modern birds, including eggshell microstructure and iterative egg production. Nevertheless, debate exists concerning their incubation strategies. Here we estimate incubation period for the troodontid,Troodon formosus, by examining a near-term embryonic tooth. Synchrotron scanning and histologic thin sections allowed counting of daily (von Ebner) growth lines. The tooth preserves 31 intact lines with an average spacing of 3.3 ± 0.96 μm. Adding 8 more for the missing crown tip gives a total age of 39 days. Modern crocodilians begin to establish their functional dentition at approximately 47% through incubation. Thus, this tooth age suggests aTroodonincubation period of 74 days, falling midway between avian (44.4 days) and reptilian (107.3 days) values predicted by theTroodonegg mass (314 g). An accelerated incubation relative to modern reptiles supports brooding and concurs with a suite of features in oviraptorosaurs and troodontids (sequential laying, large complex clutches, and precocial young) that appear dependent upon both adult body and incubation temperatures elevated over ambient conditions. However, the largely buried condition ofTroodonclutches may have prohibited efficient brooding, necessitating longer incubation than that of modern birds with fully exposed eggs.
Spinal arthritis in cane toads across the Australian landscape
Authors: Bower Deborah S. , Yasumiba Kiyomi , Trumbo Daryl R. , Alford Ross A. , Schwarzkopf Lin 
Published: August 2018

AbstractLoss of fitness can be a consequence of selection for rapid dispersal ability in invasive species. Increased prevalence of spinal arthritis may occur in cane toad populations at the invasion front as a cost of increased invasiveness, but our knowledge of the ecological drivers of this condition is lacking. We aimed to determine the factors explaining the prevalence of spinal arthritis in populations across the Australian landscape. We studied populations across a gradient of invasion histories. We collected 2415 toads over five years and determined the presence and size of spondylosis for each individual. We examined the effect of host size, leg length and invasion history on the prevalence of spondylosis. Host size was a significant predictor of spondylosis across populations. Contrary to our expectation, the overall prevalence of spondylosis was not positively related to invasion history and did not correlate with toad relative leg length. Rather than invasion age, the latitude at which populations were sampled provided an alternate explanation for the prevalence of spondylosis in cane toad populations and suggested that the incidence of this condition did not increase as a physiological cost of invasion, but is instead related to physical variables, such as climate.
Hydrodynamic trapping measures the interaction between membrane-associated molecules
Authors: Junghans Victoria , Hladilkova Jana , Santos Ana Mafalda , Lund Mikael , Davis Simon J. , Jönsson Peter 
Published: August 2018

AbstractHow membrane proteins distribute and behave on the surface of cells depends on the molecules’ chemical potential. However, measuring this potential, and how it varies with protein-to-protein distance, has been challenging. Here, we present a method we call hydrodynamic trapping that can achieve this. Our method uses the focused liquid flow from a micropipette to locally accumulate molecules protruding above a lipid membrane. The chemical potential, as well as information about the dimensions of the studied molecule, are obtained by relating the degree of accumulation to the strength of the trap. We have used this method to study four representative proteins, with different height-to-width ratios and molecular properties; from globular streptavidin, to the rod-like immune cell proteins CD2, CD4 and CD45. The data we obtain illustrates how protein shape, glycosylation and flexibility influence the behaviour of membrane proteins, as well as underlining the general applicability of the method.
Projected Increase in Hydropower Production in India under Climate Change
Authors: Ali Syed Azhar , Aadhar Saran , Shah Harsh L. , Mishra Vimal 
Published: August 2018

AbstractHydropower is a valuable renewable energy resource in India, which can help in climate change mitigation and meet the increasing energy demands. However, the crucial role of climate change on hydropower production in India remains unexplored. Here using the observations and model simulations, we show that seven large hydropower projects experienced a significant (p-value < 0.05) warming and a decline in precipitation and streamflow during the observed period of 1951–2007. However, all the hydropower projects are projected to experience a warmer and wetter climate in the future. Multimodel ensemble mean annual average temperature (precipitation) is projected to rise up to 6.3 ± 1.6 °C (18 ± 14.6%) in the catchments upstream of the other reservoirs by the end of the 21st century under representative concentration pathway (RCP) 8.5. Due to the projected increase in precipitation, mean annual streamflow (up to +45%) and hydropower (up to +25%) production are projected to rise under the future climate. However, significant warming (6.25 ± 1.62 °C) is projected to result in a decline in streamflow and hydropower production in May- June for snow-dominated Nathpa Jhakri and Bhakra Nangal hydropower projects. Our results provide insights into the development and planning of hydropower projects in India under the current projected future climate.
Identification of novel sesquiterpene synthase genes that mediate the biosynthesis of valerianol, which was an unknown ingredient of tea
Authors: Hattan Jun-ichiro , Shindo Kazutoshi , Sasaki Tetsuya , Ohno Fumina , Tokuda Harukuni , Ishikawa Kazuhiko , Misawa Norihiko 
Published: August 2018

AbstractSeven cDNA clones encoding terpene synthases (TPSs), their structures closely related to each other, were isolated from the flower of Camellia hiemalis (‘Kantsubaki’). Their putative TPS proteins were phylogenetically positioned in a sole clade with the TPSs of other Camellia species. The obtained Tps genes, one of which was designated ChTps1 (ChTps1a), were introduced into mevalonate-pathway-engineered Escherichia coli, which carried the genes for utilizing acetoacetate as a substrate, and cultured in a medium including lithium acetoacetate. Volatile products generated in the E. coli cells transformed with ChTps1 were purified from the cell suspension culture, and analyzed by NMR. Consequently, the predominant product with ChTPS1 was identified as valerianol, indicating that the ChTps1 gene codes for valerianol synthase. This is the first report on a gene that can mediate the synthesis of valerianol. We next synthesized a Tps ortholog encoding ChTPS1variant R477H (named CsiTPS8), whose sequence had been isolated from a tea tree (Camellia sinensis), carried out similar culture experiment with the E. coli transformant including CsiTps8, and consequently found valerianol production equally. Furthermore, GC-MS analysis of several teas revealed that valerianol had been an unknown ingredient in green tea and black tea.