bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Single-Ion Reservoir as a High-Sensitive Sensor of Electric Signals
Authors: Domínguez Francisco , Arrazola Iñigo , Doménech Jaime , Pedernales Julen S. , Lamata Lucas , Solano Enrique , Rodríguez Daniel 
Published: August 2017

AbstractA single-ion reservoir has been tested, and characterized in order to be used as a highly sensitive optical detector of electric signals arriving at the trapping electrodes. Our system consists of a single laser-cooled40Ca+ion stored in a Paul trap with rotational symmetry. The performance is observed through the axial motion of the ion, which is equivalent to an underdamped and forced oscillator. Thus, the results can be projected also to Penning traps. We have found that, for an ion oscillator temperatureTaxial ≲ 10 mK in the forced-frequency rangeωz = 2π × (80,200 kHz), the reservoir is sensitive to a time-varying electric field equivalent to an electric force of 5.3(2) neV/μm, for a measured quality factorQ = 3875(45), and a decay time constantγz = 88(2) s−1. This method can be applied to measure optically the strength of an oscillating field or induced (driven) charge in this frequency range within times of tens of milliseconds. Furthermore the ion reservoir has been proven to be sensitive to electrostatic forces by measuring the ion displacement. Since the heating rate is below 0.3 μeV/s, this reservoir might be used as optical detector for any ion or bunch of charged particles stored in an adjacent trap.
From virus isolation to metagenome generation for investigating viral diversity in deep-sea sediments
Authors: Corinaldesi Cinzia , Tangherlini Michael , Dell’Anno Antonio 
Published: August 2017

AbstractViruses are the most abundant and, likely, one of the most diverse biological components in the oceans. By infecting their hosts, they play key roles in biogeochemical cycles and ecosystem functioning at a global scale. The ocean interior hosts most of the microbial life, and, despite deep-sea sediments represent the main repository of this component and the largest biome on Earth, viral diversity in these ecosystems remains almost completely unknown. We compared a physical-chemical procedure and a previously published sediment washing-based procedure for isolating viruses from benthic deep-sea ecosystems to generate viromes through high-throughput sequencing. The procedure based on a physical-chemical dislodgment of viral particles from the sediments, followed by vacuum filtration was much more efficient allowing us to recover >85% of the extractable viruses. By using this procedure, a high fraction of viral DNA was recovered and new viromes from different benthic deep-sea sites were generated. Such viromes were diversified in terms of both viral families and putative functions. Overall, the results presented here provide new insights for evaluating benthic deep-sea viral diversity through metagenomic analyses, and reveal that deep-sea sediments are a hot spot of novel viral genotypes and functions.
Pollinator importance networks illustrate the crucial value of bees in a highly speciose plant community
Authors: Ballantyne Gavin , Baldock Katherine C. R. , Rendell Luke , Willmer P. G. 
Published: August 2017

AbstractAccurate predictions of pollination service delivery require a comprehensive understanding of the interactions between plants and flower visitors. To improve measurements of pollinator performance underlying such predictions, we surveyed visitation frequency, pollinator effectiveness (pollen deposition ability) and pollinator importance (the product of visitation frequency and effectiveness) of flower visitors in a diverse Mediterranean flower meadow. With these data we constructed the largest pollinator importance network to date and compared it with the corresponding visitation network to estimate the specialisation of the community with greater precision. Visitation frequencies at the community level were positively correlated with the amount of pollen deposited during individual visits, though rarely correlated at lower taxonomic resolution. Bees had the highest levels of pollinator effectiveness, withApis,Andrena,Lasioglossumand Osmiini bees being the most effective visitors to a number of plant species. Bomblyiid flies were the most effective non-bee flower visitors. Predictions of community specialisation (H2′) were higher in the pollinator importance network than the visitation network, mirroring previous studies. Our results increase confidence in existing measures of pollinator redundancy at the community level using visitation data, while also providing detailed information on interaction quality at the plant species level.
Boron-Incorporating Silicon Nanocrystals Embedded in SiO2: Absence of Free Carriers vs. B-Induced Defects
Authors: Hiller Daniel , López-Vidrier Julian , Gutsch Sebastian , Zacharias Margit , Wahl Michael , Bock Wolfgang , Brodyanski Alexander , Kopnarski Michael , Nomoto Keita , Valenta Jan , König Dirk 
Published: August 2017

AbstractBoron (B) doping of silicon nanocrystals requires the incorporation of a B-atom on a lattice site of the quantum dot and its ionization at room temperature. In case of successful B-doping the majority carriers (holes) should quench the photoluminescence of Si nanocrystals via non-radiative Auger recombination. In addition, the holes should allow for a non-transient electrical current. However, on the bottom end of the nanoscale, both substitutional incorporation and ionization are subject to significant increase in their respective energies due to confinement and size effects. Nevertheless, successful B-doping of Si nanocrystals was reported for certain structural conditions. Here, we investigate B-doping for small, well-dispersed Si nanocrystals with low and moderate B-concentrations. While small amounts of B-atoms are incorporated into these nanocrystals, they hardly affect their optical or electrical properties. If the B-concentration exceeds ~1 at%, the luminescence quantum yield is significantly quenched, whereas electrical measurements do not reveal free carriers. This observation suggests a photoluminescence quenching mechanism based on B-induced defect states. By means of density functional theory calculations, we prove that B creates multiple states in the bandgap of Si and SiO2. We conclude that non-percolated ultra-small Si nanocrystals cannot be efficiently B-doped.
Strain-dependence of the Angelman Syndrome phenotypes in Ube3a maternal deficiency mice
Authors: Born Heather A. , Dao An T. , Levine Amber T. , Lee Wai Ling , Mehta Natasha M. , Mehra Shubhangi , Weeber Edwin J. , Anderson Anne E. 
Published: August 2017

AbstractAngelman syndrome (AS) is a genetic neurodevelopmental disorder, most commonly caused by deletion or mutation of the maternal allele of the UBE3A gene, with behavioral phenotypes and seizures as key features. Currently no treatment is available, and therapeutics are often ineffective in controlling AS-associated seizures. Previous publications using the Ube3a maternal deletion model have shown behavioral and seizure susceptibility phenotypes, however findings have been variable and merit characterization of electroencephalographic (EEG) activity. In this study, we extend previous studies comparing the effect of genetic background on the AS phenotype by investigating the behavioral profile, EEG activity, and seizure threshold. AS C57BL/6J mice displayed robust behavioral impairments, spontaneous EEG polyspikes, and increased cortical and hippocampal power primarily driven by delta and theta frequencies. AS 129 mice performed poorly on wire hang and contextual fear conditioning and exhibited a lower seizure threshold and altered spectral power. AS F1 hybrid mice (C57BL/6J × 129) showed milder behavioral impairments, infrequent EEG polyspikes, and fewer spectral power alterations. These findings indicate the effect of common genetic backgrounds on the Ube3a maternal deletion behavioral, EEG, and seizure threshold phenotypes. Our results will inform future studies on the optimal strain for evaluating therapeutics with different AS-like phenotypes.
Macroalgal browsing on a heavily degraded, urbanized equatorial reef system
Authors: Bauman Andrew G. , Hoey Andrew S. , Dunshea Glenn , Feary David A. , Low Jeffrey , Todd Peter A. 
Published: August 2017

AbstractThe removal of macroalgal biomass is critical to the health of coral reef ecosystems. Previous studies on relatively intact reefs with diverse and abundant fish communities have quantified rapid removal of macroalgae by herbivorous fishes, yet how these findings relate to degraded reef systems where fish diversity and abundance are markedly lower and algal biomass substantially higher, is unclear. We surveyed roving herbivorous fish communities and quantified their capacity to remove the dominant macroalga Sargassum ilicifolium on seven reefs in Singapore; a heavily degraded urbanized reef system. The diversity and abundance of herbivorous fishes was extremely low, with eight species and a mean abundance ~1.1 individuals 60 m−2 recorded across reefs. Consumption of S. ilicifolium varied with distance from Singapore’s main port with consumption being 3- to 17-fold higher on reefs furthest from the port (Pulau Satumu: 4.18 g h−1; Kusu Island: 2.38 g h−1) than reefs closer to the port (0.35–0.78 g h−1). Video observations revealed a single species, Siganus virgatus, was almost solely responsible for removing S. ilicifolium biomass, accounting for 83% of the mass-standardized bites. Despite low herbivore diversity and intense urbanization, macroalgal removal by fishes on some Singaporean reefs was directly comparable to rates reported for other inshore Indo-Pacific reefs.
Comparison between spectral analysis and symbolic dynamics for heart rate variability analysis in the rat
Authors: Silva Luiz Eduardo Virgilio , Geraldini Victor Rezende , de Oliveira Bianca Potratz , Silva Carlos Alberto Aguiar , Porta Alberto , Fazan Rubens 
Published: August 2017

AbstractSpectral analysis of heart rate (HR) has been widely used to assess the autonomic cardiovascular control. A nonlinear approach, known as symbolic analysis, has been reported to be very useful to assess the autonomic control of cardiovascular system in humans, but very few studies reported on the differences between these two approaches on experimental models. Two distinct approaches were used to elicit autonomic changes in conscious Wistar rats: (1) pharmacological blockade of cardiac autonomic receptors with atenolol (ATE, N = 9) or methylatropine (ATR, N = 9) and (2) mild changes in arterial pressure (AP) induced by phenylephrine (PHE, N = 9) or sodium nitroprusside (NPS, N = 9). Series of cardiac interval (CI) and systolic AP (SAP) were assessed using spectral analysis and symbolic dynamics. Results show that, for spectral analysis, the power in high frequency band of CI and the power in low frequency band of SAP are the most reliable indices of vagal and sympathetic modulation, respectively. For symbolic analysis, results point 0V% and 1V% to be related to sympathetic and 2UV% to vagal modulation. Interestingly, the incidence of 1V patterns, hitherto with unknown meaning, was revealed the best index of sympathetic modulation in the rat and should be accounted for in the future studies.
Variations in biocorona formation related to defects in the structure of single walled carbon nanotubes and the hyperlipidemic disease state
Authors: Raghavendra Achyut J. , Fritz Kristofer , Fu Sherleen , Brown Jared M. , Podila Ramakrishna , Shannahan Jonathan H. 
Published: August 2017

AbstractBall-milling utilizes mechanical stress to modify properties of carbon nanotubes (CNTs) including size, capping, and functionalization. Ball-milling, however, may introduce structural defects resulting in altered CNT-biomolecule interactions. Nanomaterial-biomolecule interactions result in the formation of the biocorona (BC), which alters nanomaterial properties, function, and biological responses. The formation of the BC is governed by the nanomaterial physicochemical properties and the physiological environment. Underlying disease states such as cardiovascular disease can alter the biological milieu possibly leading to unique BC identities. In this ex vivo study, we evaluated variations in the formation of the BC on single-walled CNTs (SWCNTs) due to physicochemical alterations in structure resulting from ball-milling and variations in the environment due to the high-cholesterol disease state. Increased ball-milling time of SWCNTs resulted in enhanced structural defects. Following incubation in normal mouse serum, label-free quantitative proteomics identified differences in the biomolecular content of the BC due to the ball-milling process. Further, incubation in cholesterol-rich mouse serum resulted in the formation of unique BCs compared to SWCNTs incubated in normal serum. Our study demonstrates that the BC is modified due to physicochemical modifications such as defects induced by ball-milling and physiological disease conditions, which may result in variable biological responses.
Monolithic beam steering in a mid-infrared, surface-emitting, photonic integrated circuit
Authors: Slivken Steven , Wu Donghai , Razeghi Manijeh 
Published: August 2017

AbstractThe mid-infrared (2.5 < λ < 25 μm) spectral region is utilized for many purposes, such as chemical/biological sensing, free space communications, and illuminators/countermeasures. Compared to near-infrared optical systems, however, mid-infrared component technology is still rather crude, with isolated components exhibiting limited functionality. In this manuscript, we make a significant leap forward in mid-infrared technology by developing a platform which can combine functions of multiple mid-infrared optical elements, including an integrated light source. In a single device, we demonstrate wide wavelength tuning (240 nm) and beam steering (17.9 degrees) in the mid-infrared with a significantly reduced beam divergence (down to 0.5 degrees). The architecture is also set up to be manufacturable and testable on a wafer scale, requiring no cleaved facets or special mirror coating to function.
Sarcopenia is independently associated with diabetic foot disease
Authors: Cheng Qingfeng , Hu Jinbo , Yang Ping , Cao Xueting , Deng Xuefeng , Yang Qin , Liu Zhiping , Yang Shumin , Goswami Richa , Wang Yue , Luo Ting , Liao Kun , Li Qifu 
Published: August 2017

AbstractThe aim of this study was to investigate the association of sarcopenia and diabetic foot disease (DFD) in a cross-sectional study. Body composition was assessed using dual-energy X-ray-absorptiometry (DXA) among 1105 patients with type 2 diabetes (120 patients with newly diagnosed DFD [DFD duration less than 3 months]). Severity of DFD was assessed, referring to foot ulcers, Wagner grade and the percentage of amputation. Skeletal muscle index (SMI) was calculated, and sarcopenia was defined as SMI less than 7.0 kg/m2 (in men) or 5.4 kg/m2 (in women). SMI was significantly decreased in patients with DFD compared to patients without (6.79 ± 1.20 vs. 7.21 ± 1.05 kg/m2, P < 0.001). The percentage of sarcopenia in DFD patients was more than double than those without DFD (35.3% vs. 16.4%, P < 0.001). Multivariable logistic regression analysis showed that sarcopenia was independently associated with DFD (OR 2.05[95% CI 1.15,3.89], P = 0.027) after controlling confounders including age, diabetic duration and diabetic chronic complications. In DFD group, patients with sarcopenia exhibited more foot ulcers, higher Wagner grade and greater percentage of amputation compared to patients without sarcopenia. We conclude that sarcopenia is independently associated with DFD. Worse prognosis is seen in patients with DFD accompanied by sarcopenia.
Understanding Tribofilm Formation Mechanisms in Ionic Liquid Lubrication
Authors: Zhou Yan , Leonard Donovan N. , Guo Wei , Qu Jun 
Published: August 2017

AbstractIonic liquids (ILs) have recently been developed as a novel class of lubricant anti-wear (AW) additives, but the formation mechanism of their wear protective tribofilms is not yet well understood. Unlike the conventional metal-containing AW additives that self-react to grow a tribofilm, the metal-free ILs require a supplier of metal cations in the tribofilm growth. The two apparent sources of metal cations are the contact surface and the wear debris, and the latter contains important ‘historical’ interface information but often is overlooked. We correlated the morphological and compositional characteristics of tribofilms and wear debris from an IL-lubricated steel–steel contact. A complete multi-step formation mechanism is proposed for the tribofilm of metal-free AW additives, including direct tribochemical reactions between the metallic contact surface with oxygen to form an oxide interlayer, wear debris generation and breakdown, tribofilm growth via mechanical deposition, chemical deposition, and oxygen diffusion.
Designing of metallic nanocrystals embedded in non-stoichiometric perovskite nanomaterial and its surface-electronic characteristics
Authors: Suriyaprakash Jagadeesh , Xu Y. B. , Zhu Y. L. , Yang L. X. , Tang Y. L. , Wang Y. J. , Li S. , Ma X. L. 
Published: August 2017

AbstractEngineering of novel functional nanocomposite as like as the metallic nanocrystals supported non-stoichiometric perovskite nanomaterial in controlled parameters (size, shape and ratio of chemical characteristics) is a challengeable task. In this context, we present a facile route to fabricate and study its physicochemical property at real time mode in this report. Nanoscale pure Pb crystals surfaced on non-stoichiometric A-site deficient Pb1-xTiO3-y nanoparticle were fabricated when a precursor lead titanate (PbTiO3) nanoparticle was exposed to an electron beam irradiation (EBI) in a transmission electron microscope (TEM) at ambient temperature. In the state of the art, the chemical states and electronic structure of non-irradiated and irradiated PbTiO3 were studied by X-ray photoelectron spectroscopy (XPS). Electron bombardment resulted in a new visible feature at low binding energy in the Pb 4f core level, while Ti 2p and O 1s line shape showed slight changes. The Fermi level of the corresponding materials was determined to be 1.65 ± 0.1 eV and 2.05 ± 0.1 eV above the valence band maximum, respectively. The normal, weakly p-type PTO exhibits peculiar n-type feature after EBI process (The Fermi level moves near to the conduction band). A feasible mechanism is proposed involving the electron-stimulated local bond-breaking phenomenon in PbTiO3.
Oncofetal HMGA2 effectively curbs unconstrained (+) and (−) DNA supercoiling
Authors: Zhao Xiaodan , Peter Sabrina , Dröge Peter , Yan Jie 
Published: August 2017

AbstractHMGA2 belongs to the family of the high mobility group (HMG) proteins. It binds DNA via three AT-hook domains to the minor groove of adenine-thymine (AT) rich DNA. Recently, a new function of HMGA2 as a replication fork chaperone that protects stem and cancer cells from replication fork collapse induced by chemotherapeutic agents was uncovered, suggesting a previously uncharacterized binding at replication forks. In this study, we examined HMGA2 binding to four DNA structures relevant to replication forks, namely ds DNA, ss DNA, forked DNA and supercoiled DNA plectonemes. We detected HMGA2 binding to supercoiled DNA at the lowest concentration and this binding mode transiently stabilizes the supercoiled plectonemes against relaxation by type I topoisomerase. Together, these findings suggest a plausible mechanism how fork regression and collapse are attenuated by HMGA2 during replication stress, i.e. through transient stabilization of positively supercoiled plectonemes in the parental duplex.
Transplantation of bioengineered rat lungs recellularized with endothelial and adipose-derived stromal cells
Authors: Doi Ryoichiro , Tsuchiya Tomoshi , Mitsutake Norisato , Nishimura Satoshi , Matsuu-Matsuyama Mutsumi , Nakazawa Yuka , Ogi Tomoo , Akita Sadanori , Yukawa Hiroshi , Baba Yoshinobu , Yamasaki Naoya , Matsumoto Keitaro , Miyazaki Takuro , Kamohara Ryotaro , Hatachi Go , Sengyoku Hideyori , Watanabe Hironosuke , Obata Tomohiro , Niklason Laura E. , Nagayasu Takeshi 
Published: August 2017

AbstractBioengineered lungs consisting of a decellularized lung scaffold that is repopulated with a patient’s own cells could provide desperately needed donor organs in the future. This approach has been tested in rats, and has been partially explored in porcine and human lungs. However, existing bioengineered lungs are fragile, in part because of their immature vascular structure. Herein, we report the application of adipose-derived stem/stromal cells (ASCs) for engineering the pulmonary vasculature in a decellularized rat lung scaffold. We found that pre-seeded ASCs differentiated into pericytes and stabilized the endothelial cell (EC) monolayer in nascent pulmonary vessels, thereby contributing to EC survival in the regenerated lungs. The ASC-mediated stabilization of the ECs clearly reduced vascular permeability and suppressed alveolar hemorrhage in an orthotopic transplant model for up to 3 h after extubation. Fibroblast growth factor 9, a mesenchyme-targeting growth factor, enhanced ASC differentiation into pericytes but overstimulated their proliferation, causing a partial obstruction of the vasculature in the regenerated lung. ASCs may therefore provide a promising cell source for vascular regeneration in bioengineered lungs, though additional work is needed to optimize the growth factor or hormone milieu for organ culture.
Down-regulation of PDK4 is Critical for the Switch of Carbohydrate Catabolism during Syncytialization of Human Placental Trophoblasts
Authors: Liu Xiaohui , Zuo Rujuan , Bao Yirong , Qu Xiaoxian , Sun Kang , Ying Hao 
Published: August 2017

AbstractPyruvate dehydrogenase kinase (PDK) is known as a gatekeeper directing the carbon flux into glycolysis via inhibition of the pyruvate dehydrogenase complex. During syncytialization of placental trophoblasts, both ATP production and oxygen consumption are increased to meet enhanced energetic demands by syntiotrophoblasts. We hypothesized that down-regulation of PDK expression may play a central role in the switch from glycolysis to oxidative phosphorylation (OXPHOS) during syncytialization. By using primary human trophoblasts, we demonstrated that PDK4 was the dominating PDK isoform in human cytotrophoblasts, and its abundance was substantially decreased upon syncytialization, which was accompanied by decreases in lactate production and increases in ATP production. Knock-down of PDK4 expression reduced lactate production and increased ATP production, while over-expression of PDK4 increased lactate production and decreased ATP production, indicating that down-regulation of PDK4 is key to the shift from glycolysis to OXPHOS during syncytialization. Moreover, human chorionic gonadotropin (hCG)/cAMP/PKA pathway was demonstrated to be involved in the down-regulation of PDK4 expression upon syncytialization. Taken together, our findings disclosed that down-regulation of PDK4 is critical for the metabolic shift from glycolysis to OXPHOS during syncytialization, which may be a prerequisite for the proper implementation of syncytiotrophoblast functions.