bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the Isotopic Signature of Atmospheric Nitrous Oxide and Its Global Average Source During the Last Three Millennia
Authors: Prokopiou M. , Sapart C. J. , Rosen J. , Sperlich P. , Blunier T. , Brook E. , van de Wal R. S. W. , Röckmann T. 
Published: August 2018

AbstractNitrous oxide (N2O) is a strong greenhouse gas whose mole fraction in the atmosphere has increased over the industrial period. We present a new set of isotope measurements of N2O in air extracted from ice cores covering the last 3,000 years. For the preindustrial (PI) atmosphere, we find an average N2O mole fraction of (267 ± 1) nmol/mol and average tropospheric N2O isotopic values of δ15NavPI = (9.5 ± 0.1)‰, δ18OPI = (47.1 ± 0.2)‰, δ15NαPI = (17.8 ± 0.4)‰, and δ15ΝβPI = (1.2 ± 0.4)‰. From PI to modern times all isotope signatures decreased with a total change of δ15Nav = (−2.7 ± 0.2)‰, δ18O = (−2.5 ± 0.4)‰, δ15Nα = (−2.0 ± 0.7)‰, and δ15Νβ (−3.5 ± 0.7)‰. Interestingly, the temporal evolution is not the same for δ15Nav and δ18O. δ18O trends are relatively larger during the early part, and δ15Nav trends are larger during the late part of the industrial period, implying a decoupling of sources over the industrial period. Using a mass balance model, we determined the isotopic composition of the total average N2O source. Assuming that the total present source is the sum of a constant natural source and an increasing anthropogenic source, this anthropogenic source has an isotopic signature of δ15Navsource,anthrop = (−15.0 ± 2.6)‰, δ18Osource,anthrop = (30.0 ± 2.6)‰, δ15Nαsource,anthrop = (−4.5 ± 1.7)‰, and δ15Nβsource,anthrop = (−24.0 ± 8.4)‰. The 15N site preference of the source has increased since PI times, which is indicative of a relative shift from denitrification to nitrification sources, consistent with agricultural emissions playing a major role in the N2O increase.
Simultaneous Rayleigh‐Scatter and Sodium Resonance Lidar Temperature Comparisons in the Mesosphere‐Lower Thermosphere
Authors: Sox Leda , Wickwar Vincent B. , Yuan Tao , Criddle Neal R. 
Published: August 2018

AbstractThe Utah State University (USU) campus (41.7°N, 111.8°W) hosts a unique upper atmospheric observatory that houses both a high‐power, large‐aperture Rayleigh lidar and a Na lidar. For the first time, we will present 19 nights of coordinated temperature measurements from the two lidars, overlapping in the 80–110 km observational range, over one annual cycle (summer 2014 to summer 2015). This overlap has been achieved through upgrades to the existing USU Rayleigh lidar that increased its observational altitude from 45–95 to 70–115 km and by relocating the Colorado State Na lidar to the USU campus. Previous climatological comparisons between Rayleigh and Na lidar temperatures have suggested that significant temperature differences exist between the two techniques. This new comparison aims to further these previous studies by using simultaneous, common‐volume observations. The present comparison showed the best agreement between 85 and 95 km, with a temperature difference, averaged over the whole data set, of about 1.1 ± 0.5 K. Larger differences occurred above and below these altitudes with the Rayleigh temperatures being colder by about 3.5 ± 0.5 K at 82 km and warmer by up to 9.1 ± 3.5 K above 95 km.
Strong succession in arbuscular mycorrhizal fungal communities
Authors: Gao Cheng , Montoya Liliam , Xu Ling , Madera Mary , Hollingsworth Joy , Purdom Elizabeth , Hutmacher Robert B , Dahlberg Jeffery A , Coleman-Derr Devin , Lemaux Peggy G , Taylor John W 
Published: August 2018

Abstract
The ecology of fungi lags behind that of plants and animals because most fungi are microscopic and hidden in their substrates. Here, we address the basic ecological process of fungal succession in nature using the microscopic, arbuscular mycorrhizal fungi (AMF) that form essential mutualisms with 70–90% of plants. We find a signal for temporal change in AMF community similarity that is 40-fold stronger than seen in the most recent studies, likely due to weekly samplings of roots, rhizosphere and soil throughout the 17 weeks from seedling to fruit maturity and the use of the fungal DNA barcode to recognize species in a simple, agricultural environment. We demonstrate the patterns of nestedness and turnover and the microbial equivalents of the processes of immigration and extinction, that is, appearance and disappearance. We also provide the first evidence that AMF species co-exist rather than simply co-occur by demonstrating negative, density-dependent population growth for multiple species. Our study shows the advantages of using fungi to test basic ecological hypotheses (e.g., nestedness v. turnover, immigration v. extinction, and coexistence theory) over periods as short as one season.
Aberrant activation of latent transforming growth factor-β initiates the onset of temporomandibular joint osteoarthritis
Authors: Zheng Liwei , Pi Caixia , Zhang Jun , Fan Yi , Cui Chen , Zhou Yang , Sun Jianxun , Yuan Quan , Xu Xin , Ye Ling , Cao Xu , Zhou Xuedong 
Published: August 2018

AbstractThere is currently no effective medical treatment for temporomandibular joint osteoarthritis (TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transforming growth factor-β (TGF-β) signalling in the cartilage and subchondral bone of the TMJ using a temporomandibular joint disorder (TMD) rat model, an ageing mouse model and a Camurati–Engelmann disease (CED) mouse model. In the three animal models, the subchondral bone phenotypes in the mandibular condyles were evaluated by µCT, and changes in TMJ condyles were examined by TRAP staining and immunohistochemical analysis of Osterix and p-Smad2/3. Condyle degradation was confirmed by Safranin O staining, the Mankin and OARSI scoring systems and type X collagen (Col X), p-Smad2/3a and Osterix immunohistochemical analyses. We found apparent histological phenotypes of TMJ-OA in the TMD, ageing and CED animal models, with abnormal activation of TGF-β signalling in the condylar cartilage and subchondral bone. Moreover, inhibition of TGF-β receptor I attenuated TMJ-OA progression in the TMD models. Therefore, aberrant activation of TGF-β signalling could be a key player in TMJ-OA development.
Nuclear Nestin deficiency drives tumor senescence via lamin A/C-dependent nuclear deformation
Authors: Zhang Yanan , Wang Jiancheng , Huang Weijun , Cai Jianye , Ba Junhui , Wang Yi , Ke Qiong , Huang Yinong , Liu Xin , Qiu Yuan , Lu Qiying , Sui Xin , Shi Yue , Wang Tao , Shen Huiyong , Guan Yuanjun , Zhou Ying , Chen Yuan , Wang Maosheng , Xiang Andy Peng 
Published: August 2018

AbstractEmerging evidence has revealed that Nestin not only serves as a biomarker for multipotent stem cells, but also regulates cell proliferation and invasion in various tumors. However, the mechanistic contributions of Nestin to cancer pathogenesis are still unknown. In the present study, previously thought to reside exclusively in the cytoplasm, Nestin can also be found in the nucleus and participate in protecting tumor cells against cellular senescence. Specifically, we reveal that Nestin has a nuclear localization signal (aa318–aa347) at the downstream of rod domain. We then find nuclear Nestin could interact with lamin A/C. Mechanistic investigations demonstrate that Nestin depletion results in the activation of cyclin-dependent kinase 5 (Cdk5), which causes the phosphorylation of lamin A/C (mainly at S392 site) and its subsequent translocation to the cytoplasm for degradation. The findings establish a role for nuclear Nestin in tumor senescence, which involves its nucleus-localized form and interaction with lamin A/C.
Structure of the human plasma membrane Ca2+-ATPase 1 in complex with its obligatory subunit neuroplastin
Authors: Gong Deshun , Chi Ximin , Ren Kang , Huang Gaoxingyu , Zhou Gewei , Yan Nieng , Lei Jianlin , Zhou Qiang 
Published: August 2018

AbstractPlasma membrane Ca2+-ATPases (PMCAs) are key regulators of global Ca2+ homeostasis and local intracellular Ca2+ dynamics. Recently, Neuroplastin (NPTN) and basigin were identified as previously unrecognized obligatory subunits of PMCAs that dramatically increase the efficiency of PMCA-mediated Ca2+ clearance. Here, we report the cryo-EM structure of human PMCA1 (hPMCA1) in complex with NPTN at a resolution of 4.1 Å for the overall structure and 3.9 Å for the transmembrane domain. The single transmembrane helix of NPTN interacts with the TM8-9-linker and TM10 of hPMCA1. The subunits are required for the hPMCA1 functional activity. The NPTN-bound hPMCA1 closely resembles the E1-Mg2+ structure of endo(sarco)plasmic reticulum Ca2+ ATPase and the Ca2+ site is exposed through a large open cytoplasmic pathway. This structure provides insight into how the subunits bind to the PMCAs and serves as an important basis for understanding the functional mechanisms of this essential calcium pump family.
Percolative nature of the direct-current paraconductivity in cuprate superconductors
Authors: Popčević Petar , Pelc Damjan , Tang Yang , Velebit Kristijan , Anderson Zachary , Nagarajan Vikram , Yu Guichuan , Požek Miroslav , Barišić Neven , Greven Martin 
Published: August 2018

AbstractDespite extraordinary scientific efforts over the past three decades, the cuprate high-temperature superconductors continue to pose formidable challenges. A pivotal problem, essential for understanding both the normal and superconducting states, is to clarify the nature of the superconducting pre-pairing above the bulk transition temperature Tc. Different experimental probes have given conflicting results, in part due to difficulties in discerning the superconducting response from the complex normal-state behavior. Moreover, it has proven challenging to separate common properties of the cuprates from compound-specific idiosyncrasies. Here we investigate the paraconductivity—the superconducting contribution to the direct-current (dc) conductivity—of the simple-tetragonal model cuprate material HgBa2CuO4+δ. We are able to separate the superconducting and normal-state responses by taking advantage of the Fermi-liquid nature of the normal state in underdoped HgBa2CuO4+δ; the robust and simple quadratic temperature-dependence of the normal-state resistivity enables us to extract the paraconductivity above the macroscopic Tc with great accuracy. We find that the paraconductivity exhibits unusual exponential temperature dependence, and that it can be quantitatively explained by a simple superconducting percolation model. Consequently, the emergence of superconductivity in this model system is dominated by the underlying intrinsic gap inhomogeneity. Motivated by these insights, we reanalyze published results for two other cuprates and find exponential behavior as well, with nearly the same characteristic temperature scale. The universal intrinsic gap inhomogeneity is not only essential for understanding the supercoducting precursor, but will also have to be taken into account in the analysis of other bulk measurements of the cuprates.
Polymeric nanocapsules embedded with ultra-small silver nanoclusters for synergistic pharmacology and improved oral delivery of Docetaxel
Authors: Sohail Muhammad Farhan , Hussain Syed Zajif , Saeed Hamid , Javed Ibrahim , Sarwar Hafiz Shoaib , Nadhman Akhtar , Huma Zil-e- , Rehman Mubashar , Jahan Sarwat , Hussain Irshad , Shahnaz Gul 
Published: August 2018

AbstractDespite of the remarkable cytotoxic and imaging potential of ultra-small metal nanoclusters, their toxicity-free and targeted delivery to cancerous cells remains a substantial challenge that hinders their clinical applications. In this study, a polymeric scaffold was first synthesized by grafting folic acid and thiol groups to chitosan (CS) for cancer cell targeting and improved gastric permeation. Furthermore, silver nanocluster (Ag NCs) were synthesized in situ, within CS scaffold by microwave irradiation and core-shell nanocapsules (NCPs) were prepared with hydrophobic docetaxel (DTX) in the core and Ag NCs embedded CS in the shell. A significant cytotoxicity synergism (~300 folds) was observed for DTX with co-delivery of Ag NCs against breast cancer MDA-MB-231 cells. Following oral administration, the DTX-Ag-NCPs increased bioavailability due to enhanced drug transport across gut (9 times), circulation half-life (~6.8 times) and mean residence time (~6.7 times), as compared to the control DTX suspension. Moreover, 14 days acute oral toxicity of the DTX-Ag-NCPs was performed in mice and evaluated for changes in blood biochemistry parameters, organ to body weight index and histopathology of liver and kidney tissues that revealed no significant evidence of toxicity suggesting the safety and efficiency of the DTX-Ag-NCPs as hybrid nanocarrier for biocompatible delivery of metal nanoclusters.
Regionally specific TSC1 and TSC2 gene expression in tuberous sclerosis complex
Authors: Li Yi , Barkovich Matthew J. , Karch Celeste M. , Nillo Ryan M. , Fan Chun-Chieh , Broce Iris J. , Tan Chin Hong , Cuneo Daniel , Hess Christopher P. , Dillon William P. , Glenn Orit A. , Glastonbury Christine M. , Olney Nicholas , Yokoyama Jennifer S. , Bonham Luke W. , Miller Bruce , Kao Aimee , Schmansky Nicholas , Fischl Bruce , Andreassen Ole A. , Jernigan Terry , Dale Anders , Barkovich A. James , Desikan Rahul S. , Sugrue Leo P. 
Published: August 2018

AbstractTuberous sclerosis complex (TSC), a heritable neurodevelopmental disorder, is caused by mutations in the TSC1 or TSC2 genes. To date, there has been little work to elucidate regional TSC1 and TSC2 gene expression within the human brain, how it changes with age, and how it may influence disease. Using a publicly available microarray dataset, we found that TSC1 and TSC2 gene expression was highest within the adult neo-cerebellum and that this pattern of increased cerebellar expression was maintained throughout postnatal development. During mid-gestational fetal development, however, TSC1 and TSC2 expression was highest in the cortical plate. Using a bioinformatics approach to explore protein and genetic interactions, we confirmed extensive connections between TSC1/TSC2 and the other genes that comprise the mammalian target of rapamycin (mTOR) pathway, and show that the mTOR pathway genes with the highest connectivity are also selectively expressed within the cerebellum. Finally, compared to age-matched controls, we found increased cerebellar volumes in pediatric TSC patients without current exposure to antiepileptic drugs. Considered together, these findings suggest that the cerebellum may play a central role in TSC pathogenesis and may contribute to the cognitive impairment, including the high incidence of autism spectrum disorder, observed in the TSC population.
mGlu1 Receptors Monopolize the Synaptic Control of Cerebellar Purkinje Cells by Epigenetically Down-Regulating mGlu5 Receptors
Authors: Notartomaso Serena , Nakao Harumi , Mascio Giada , Scarselli Pamela , Cannella Milena , Zappulla Cristina , Madonna Michele , Motolese Marta , Gradini Roberto , Liberatore Francesca , Zonta Micaela , Carmignoto Giorgio , Battaglia Giuseppe , Bruno Valeria , Watanabe Masahiko , Aiba Atsu , Nicoletti Ferdinando 
Published: August 2018

AbstractIn cerebellar Purkinje cells (PCs) type-1 metabotropic glutamate (mGlu1) receptors play a key role in motor learning and drive the refinement of synaptic innervation during postnatal development. The cognate mGlu5 receptor is absent in mature PCs and shows low expression levels in the adult cerebellar cortex. Here we found that mGlu5 receptors were heavily expressed by PCs in the early postnatal life, when mGlu1α receptors were barely detectable. The developmental decline of mGlu5 receptors coincided with the appearance of mGlu1α receptors in PCs, and both processes were associated with specular changes in CpG methylation in the corresponding gene promoters. It was the mGlu1 receptor that drove the elimination of mGlu5 receptors from PCs, as shown by data obtained with conditional mGlu1α receptor knockout mice and with targeted pharmacological treatments during critical developmental time windows. The suppressing activity of mGlu1 receptors on mGlu5 receptor was maintained in mature PCs, suggesting that expression of mGlu1α and mGlu5 receptors is mutually exclusive in PCs. These findings add complexity to the the finely tuned mechanisms that regulate PC biology during development and in the adult life and lay the groundwork for an in-depth analysis of the role played by mGlu5 receptors in PC maturation.
High Trapped Fields in C-doped MgB2 Bulk Superconductors Fabricated by Infiltration and Growth Process
Authors: Bhagurkar A. G. , Yamamoto A. , Wang L. , Xia M. , Dennis A. R. , Durrell J. H. , Aljohani T. A. , Babu N. H. , Cardwell D. A. 
Published: August 2018

AbstractThe grain boundaries in superconducting MgB2 are known to form effective magnetic flux pinning sites and, consequently, bulk MgB2 containing a fine-grain microstructure fabricated from nanoscale Mg and B precursor powders exhibits good magnetic field-trapping performance below 20 K. We report here that the trapped field of MgB2 bulk superconductors fabricated by an infiltration and growth process to yield a dense, pore-free microstructure, can be enhanced significantly by carbon-doping, which increases intra-band scattering within the superconducting grains. A maximum trapped field of 4.15 T has been measured at 7.5 K at the centre of a five-sample stack of Mg(B1−xiCxi)2 bulk superconductors processed by infiltration and growth, which not only represents a ~40% increase in trapped field observed compared to undoped bulk MgB2, but also is the highest trapped field reported to date in MgB2 samples processed under ambient pressure. The trapped field is observed to decay at a rate of <2%/day at 10 K, which suggests that bulk MgB2 superconductors fabricated using the infiltration and growth technique can be used potentially to generate stable, high magnetic fields for a variety of engineering applications.
Targeted enrichment outperforms other enrichment techniques and enables more multi-species RNA-Seq analyses
Authors: Chung Matthew , Teigen Laura , Liu Hong , Libro Silvia , Shetty Amol , Kumar Nikhil , Zhao Xuechu , Bromley Robin E. , Tallon Luke J. , Sadzewicz Lisa , Fraser Claire M. , Rasko David A. , Filler Scott G. , Foster Jeremy M. , Michalski Michelle L. , Bruno Vincent M. , Dunning Hotopp Julie C. 
Published: August 2018

AbstractEnrichment methodologies enable the analysis of minor members in multi-species transcriptomic data. We compared the standard enrichment of bacterial and eukaryotic mRNA to a targeted enrichment using an Agilent SureSelect (AgSS) capture for Brugia malayi, Aspergillus fumigatus, and the Wolbachia endosymbiont of B. malayi (wBm). Without introducing significant systematic bias, the AgSS quantitatively enriched samples, resulting in more reads mapping to the target organism. The AgSS-enriched libraries consistently had a positive linear correlation with their unenriched counterparts (r2 = 0.559–0.867). Up to a 2,242-fold enrichment of RNA from the target organism was obtained following a power law (r2 = 0.90), with the greatest fold enrichment achieved in samples with the largest ratio difference between the major and minor members. While using a single total library for prokaryote and eukaryote enrichment from a single RNA sample could be beneficial for samples where RNA is limiting, we observed a decrease in reads mapping to protein coding genes and an increase in multi-mapping reads to rRNAs in AgSS enrichments from eukaryotic total RNA libraries compared to eukaryotic poly(A)-enriched libraries. Our results support a recommendation of using AgSS targeted enrichment on poly(A)-enriched libraries for eukaryotic captures, and total RNA libraries for prokaryotic captures, to increase the robustness of multi-species transcriptomic studies.
Small noncoding RNA profiles along alternative developmental trajectories in an annual killifish
Authors: Romney Amie L. T. , Podrabsky Jason E. 
Published: August 2018

AbstractEmbryonic development of Austrofundulus limnaeus can occur along two phenotypic trajectories that are physiologically and biochemically distinct. Phenotype appears to be influenced by maternal provisioning based on the observation that young females produce predominately non-diapausing embryos and older females produce mostly diapausing embryos. Embryonic incubation temperature can override this pattern and alter trajectory. We hypothesized that temperature-induced phenotypic plasticity may be regulated by post-transcriptional modification via noncoding RNAs. As a first step to exploring this possibility, RNA-seq was used to generate transcriptomic profiles of small noncoding RNAs in embryos developing along the two alternative trajectories. We find distinct profiles of mature sequences belonging to the miR-10 family expressed in increasing abundance during development and mature sequences of miR-430 that follow the opposite pattern. Furthermore, miR-430 sequences are enriched in escape trajectory embryos. MiR-430 family members are known to target maternally provisioned mRNAs in zebrafish and may operate similarly in A. limnaeus in the context of normal development, and also by targeting trajectory-specific mRNAs. This expression pattern and function for miR-430 presents a potentially novel model for maternal-embryonic conflict in gene regulation that provides the embryo the ability to override maternal programming in the face of altered environmental conditions.
Anti-corrosive and oil sensitive coatings based on epoxy/polyaniline/magnetite-clay composites through diazonium interfacial chemistry
Authors: Jlassi Khouloud , Radwan A. Bahgat , Sadasivuni Kishor Kumar , Mrlik Miroslav , Abdullah Aboubakr M. , Chehimi Mohamed M. , Krupa Igor 
Published: August 2018

AbstractEpoxy polymer nanocomposites filled with magnetite (Fe3O4) clay (B), named (B-DPA-PANI@Fe3O4) have been prepared at different filler loading (0.1, 0.5, 1, 3, 5 wt. %). The surface modification of clay by polyaniline (PANI) is achieved in the presence of 4-diphenylamine diazonium salt (DPA). The effects of the nanofiller loading on Tensile, mechanical and dielectric properties were systematically studied. Improved properties was highlighted for all reinforced samples. The addition of only 3 wt. % of the filler enhanced the tensile strength of the composites by 256%, and the glass transition temperature Tg by 37%. The dielectric spectra over a broad frequency showed a robust interface between the hybrid (B-DPA-PANI@Fe3O4) fillers and epoxy matrix. The results showed most significant improvement in corrosion inhibition using electrochemical impedance spectroscopy (EIS) in 3.5 wt % NaCl, as well as a significant response in oil sensing test. High charge transfer resistance of 110 × 106 Ω.cm2 using 3-wt % of filler was noted compared to 0.35 × 106 Ω.cm2 for the pure epoxy. The results obtained herein will open new routes for the preparation of efficient anticorrosion sensor coatings.