bluuebunny/crossref_metadata_2025 huggingface dataset:
Far-wake meandering induced by atmospheric eddies in flow past a wind turbine
Authors: Mao X. , Sørensen J. N.
Published: May 2018

A novel algorithm is developed to calculate the nonlinear optimal boundary perturbations in three-dimensional incompressible flow. An optimal step length in the optimization loop is calculated without any additional calls to the Navier–Stokes equations. The algorithm is applied to compute the optimal inflow eddies for the flow around a wind turbine to clarify the mechanisms behind wake meandering, a phenomenon usually observed in wind farms. The turbine is modelled as an actuator disc using an immersed boundary method with the loading prescribed as a body force. At Reynolds number (based on free-stream velocity and turbine radius) $Re=1000$, the most energetic inflow perturbation has a frequency $\unicode[STIX]{x1D714}=0.8$–2, and is in the form of an azimuthal wave with wavenumber $m=1$ and the same radius as the actuator disc. The inflow perturbation is amplified by the strong shear downstream of the edge of the disc and then tilts the rolling-up vortex rings to induce wake meandering. This mechanism is verified by studying randomly perturbed flow at $Re\leqslant 8000$. At five turbine diameters downstream of the disc, the axial velocity oscillates at a magnitude of more than 60 % of the free-stream velocity when the magnitude of the inflow perturbation is 6 % of the free-stream wind speed. The dominant Strouhal number of the wake oscillation is 0.16 at $Re=3000$ and keeps approximately constant at higher $Re$. This Strouhal number agrees well with previous experimental findings. Overall the observations indicate that the well-observed stochastic wake meandering phenomenon appearing far downstream of wind turbines is induced by large-scale (the same order as the turbine rotor) and low-frequency free-stream eddies.
Wall shear stress from jetting cavitation bubbles
Authors: Zeng Qingyun , Gonzalez-Avila Silvestre Roberto , Dijkink Rory , Koukouvinis Phoevos , Gavaises Manolis , Ohl Claus-Dieter
Published: May 2018

The collapse of a cavitation bubble near a rigid boundary induces a high-speed transient jet accelerating liquid onto the boundary. The shear flow produced by this event has many applications, examples of which are surface cleaning, cell membrane poration and enhanced cooling. Yet the magnitude and spatio-temporal distribution of the wall shear stress are not well understood, neither experimentally nor by simulations. Here we solve the flow in the boundary layer using an axisymmetric compressible volume-of-fluid solver from the OpenFOAM framework and discuss the resulting wall shear stress generated for a non-dimensional distance, $\unicode[STIX]{x1D6FE}=1.0$ ($\unicode[STIX]{x1D6FE}=h/R_{max}$, where $h$ is the distance of the initial bubble centre to the boundary, and $R_{max}$ is the maximum spherical equivalent radius of the bubble). The calculation of the wall shear stress is found to be reliable once the flow region with constant shear rate in the boundary layer is determined. Very high wall shear stresses of 100 kPa are found during the early spreading of the jet, followed by complex flows composed of annular stagnation rings and secondary vortices. Although the simulated bubble dynamics agrees very well with experiments, we obtain only qualitative agreement with experiments due to inherent experimental challenges.
Self-organized oscillations of Leidenfrost drops
Authors: Ma Xiaolei , Burton Justin C.
Published: May 2018

In the Leidenfrost effect, a thin layer of evaporated vapour forms between a liquid and a hot solid. The complex interactions between the solid, liquid and vapour phases can lead to rich dynamics even in a single Leidenfrost drop. Here we investigate the self-organized oscillations of Leidenfrost drops that are excited by a constant flow of evaporated vapour beneath the drop. We show that for small Leidenfrost drops, the frequency of a recently reported ‘breathing mode’ (Caswell, Phys. Rev. E, vol. 90, 2014, 013014) can be explained by a simple balance of gravitational and surface tension forces. For large Leidenfrost drops, azimuthal star-shaped oscillations are observed. Our previous work showed how the coupling between the rapid evaporated vapour flow and the vapour–liquid interface excites the star-shaped oscillations (Ma et al., Phys. Rev. Fluids, vol. 2, 2017, 031602). In our experiments, star-shaped oscillation modes of $n=2{-}13$ are observed in different liquids, and the number of observed modes depends sensitively on the viscosity of the liquid. Here we expand on this work by directly comparing the oscillations with theoretical predictions, as well as show how the oscillations are initiated by a parametric forcing mechanism through pressure oscillations in the vapour layer. The pressure oscillations are driven by the capillary waves of a characteristic wavelength beneath the drop. These capillary waves can be generated by a large shear stress at the liquid–vapour interface due to the rapid flow of evaporated vapour. We also explore potential effects of thermal convection in the liquid. Although the measured Rayleigh number is significantly larger than the critical Rayleigh number, the frequency (wavelength) of the oscillations depends only on the capillary length of the liquid, and is independent of the drop radius and substrate temperature. Thus convection seems to play a minor role in Leidenfrost drop oscillations, which are mostly hydrodynamic in origin.
Effect of biotite on the firing characteristics of certain weathered schists
Authors: Norrish K. , Radoslovich E. W.
Published: May 2018

A study was made of five clays used for brickmaking to determine the reason why certain clays crumbled on firing. Partially weathered biotite was found to be a constituent of the clays which crumbled and the crumbling was due to this mineral exfoliating and so disrupting the bricks at a comparatively low temperature. Fresh biotite and highly weathered biotite do not have this adverse effect.
Geometric integrators and the Hamiltonian Monte Carlo method
Authors: Bou-Rabee Nawaf , Sanz-Serna J. M.
Published: May 2018

This paper surveys in detail the relations between numerical integration and the Hamiltonian (or hybrid) Monte Carlo method (HMC). Since the computational cost of HMC mainly lies in the numerical integrations, these should be performed as efficiently as possible. However, HMC requires methods that have the geometric properties of being volume-preserving and reversible, and this limits the number of integrators that may be used. On the other hand, these geometric properties have important quantitative implications for the integration error, which in turn have an impact on the acceptance rate of the proposal. While at present the velocity Verlet algorithm is the method of choice for good reasons, we argue that Verlet can be improved upon. We also discuss in detail the behaviour of HMC as the dimensionality of the target distribution increases.
Finite-volume schemes for shallow-water equations
Authors: Kurganov Alexander
Published: May 2018

Shallow-water equations are widely used to model water flow in rivers, lakes, reservoirs, coastal areas, and other situations in which the water depth is much smaller than the horizontal length scale of motion. The classical shallow-water equations, the Saint-Venant system, were originally proposed about 150 years ago and still are used in a variety of applications. For many practical purposes, it is extremely important to have an accurate, efficient and robust numerical solver for the Saint-Venant system and related models. As their solutions are typically non-smooth and even discontinuous, finite-volume schemes are among the most popular tools. In this paper, we review such schemes and focus on one of the simplest (yet highly accurate and robust) methods: central-upwind schemes. These schemes belong to the family of Godunov-type Riemann-problem-solver-free central schemes, but incorporate some upwinding information about the local speeds of propagation, which helps to reduce an excessive amount of numerical diffusion typically present in classical (staggered) non-oscillatory central schemes. Besides the classical one- and two-dimensional Saint-Venant systems, we will consider the shallow-water equations with friction terms, models with moving bottom topography, the two-layer shallow-water system as well as general non-conservative hyperbolic systems.
Scanning Transmission Electron Microscopy for Critical Dimension Monitoring in Wafer Manufacturing
Authors: Wang Haifeng , Fang Jason , Arjavac Jason , Kellner Rudy
Published: May 2018

Automated scanning transmission electron microscopy (STEM) metrology provides critical dimension (CD) measurements an order of magnitude more precise than comparable scanning electron microscopy (SEM) measurements. New developments in automation now also provide throughput and response time sufficient to support high volume microelectronic manufacturing processes. The newly developed methodology includes automated, focused ion beam (FIB) based sample preparation; innovative, ex-situ sample extraction; and automated metrology. Although originally developed to control the production of thin film magnetic heads for data storage, the technique is fully applicable to any wafer-based manufacturing process.
Passive Mirror Imaging through a Solid-State Back-Scattered Electron Detector
Authors: Croccolo Fabrizio , Riccardi Claudia
Published: May 2018

The scanning electron microscope (SEM) is commonly used to obtain images of a wide variety of samples within a wide range of magnification factors from the order of 10 up to about 105×. This technique is usually applied, but not limited to, the investigation of conductive samples. This is because the interaction of the scanning beam with the sample generates a net charge on the sample surface. Thus, if the sample is conductive, the charge can be quickly disposed of to ground, away from the beam spot. If the sample in non-conductive, the sample becomes locally charged, giving rise to a distortion of the primary beam. In certain conditions, the charge stored on the sample is able to reflect back the incoming electrons, much like an electrostatic mirror.
Beyond the Black Box: Interactive Global Docking of Protein Complexes
Authors: Heyd Jochen , Birmanns Stefan
Published: May 2018

A key to understanding the function of biological systems is the visualization of their natural state, ideally in a natural environment. At a molecular level, this is challenging. Traditional experimental techniques, like X-ray crystallography, can provide the atomic structure of proteins, but only by removing them from their native surroundings and forcing them into crystals. Over the past decade, microscopy techniques have emerged as alternatives to these traditional structure determination methods, with the advantage of visualizing molecules in a near-native state. Given the current focus of structural biology on interactions between proteins and better understanding of large protein complexes, cryo-electron microscopy (cryo-EM) has become a valuable tool.
The Use of Poly-L-lysine as an Adhesive in Scanning Electron Microscopy
Authors: Taylor Jeannette
Published: May 2018

Poly-L-lysine of a medium molecular weight, 30,000 to 70,000 Daltons (Sigma–Aldrich), is currently used in our facility as a polycationic adhesive on 5 mm square silicon chips to secure individual anionic cells and particles for ease of processing and viewing in the scanning electron microscope. In this technique, a solution of 1 mg/ml of poly-L-lysine is dissolved in distilled water. Drops of the solution are placed onto clean 5 mm square silicon chips and allowed to sit for one to several hours before being wicked away. The prepared chips are used immediately. Suspended cells are then applied to the chips and allowed to settle and adhere, after which they are washed and fixed. Alternatively, fixed suspended cells or particles are applied to these silicon chips. The cells and particles secured to the silicon chips are easily handled through processing steps such as dehydration, critical point drying, and metal sputter coating for viewing in the scanning electron microscope. Presented herein is a brief history of the evolution of the technique of using poly-L-lysine as an adhesive for SEM.
Multiscale processes in the genesis of a near‐equatorial tropical cyclone during the Dynamics of the MJO Experiment: Results from partial lateral forcing experiments
Authors: Yang Hongwei , Wang Bin
Published: May 2018

Tropical cyclone (TC) 05A (TC05A, November 2011) over the Indian Ocean originated near the equator and brought huge damages to Sri Lanka and India. The genesis and propagation of TC05A involves interactions with the Madden–Julian Oscillation (MJO), interannual (IA) variations, and other synoptic (SY) systems. To investigate the impacts of the SY, MJO, and IA forcings across the lateral boundaries on TC05A, regional simulation with the Weather Research and Forecast model through the partial lateral forcing approach is conducted. The control experiment reproduces realistic genesis and movement of TC05A and associated heavy rainfall, as well as the mean states and MJO. Both the SY and IA forcings make a moderate contribution to the initiation of cyclonic vorticity and rainfall enhancement in the central Indian Ocean and moderate modification of the TC05A track. However, it is the MJO forcing that fundamentally reproduces a coherent moist, low‐level convergence, and a cyclonic environment that is favorable for the development of TC05A. The greatest impact of northern boundary intraseasonal (IS) forcing on the genesis location and path of TC05A is further identified, suggesting the importance of the interaction between the MJO and northeast winter monsoon. In contrast, the southern boundary IS forcing is unimportant and the western and eastern boundary IS forcings play a moderate role in slowing down TC05A and modifying its track, intensity, and rainfall. This study demonstrates that the partial lateral forcing method is an effective tool to identify the key factors controlling the extreme events through regional climate modeling.
Statistical Distributions of Lightning Peak Currents: Why Do They Appear to Be Lognormal?
Authors: Slyunyaev Nikolay N. , Mareev Evgeny A. , Rakov Vladimir A. , Golitsyn Georgy S.
Published: May 2018

The statistical distribution of peak currents in cloud‐to‐ground lightning strokes is analyzed and discussed both in the context of the existing experimental data and from a theoretical viewpoint. The distributions of peak currents directly measured at instrumented towers are compared to those of peak currents reported by the U.S. National Lightning Detection Network and peak currents measured in rocket‐triggered lightning experiments; all those appear to be lognormal. To explain the observed peak current distributions, a simple model based on the large‐scale electric field evolution prior to lightning flashes is developed. Based only on the most general assumptions concerning the probability of occurrence of lightning discharge, it is shown that the distribution of the pre‐first‐stroke large‐scale electric field is close to lognormal in a certain range. With the introduction of structure factors relating the leader or cloud electric potential to this field, semiempirical relationships between the potential and the peak current in negative first and subsequent strokes imply that the peak current and pre‐first‐stroke large‐scale electric field obey distributions of the same type. It is demonstrated that with a suitable choice of parameters, the model‐predicted distributions are close to those obtained from direct measurements, and statistical tests show that their agreement with the data is at least as good as that seen for lognormal approximations.
Soil Particle Transport and Mixing Near a Hillslope Crest: 1. Particle Ages and Residence Times
Authors: Furbish David Jon , Roering Joshua J. , Almond Peter , Doane Tyler H.
Published: May 2018

We examine probabilistic elements of soil particle ages and residence times measured from their entry into the mechanically active soil column, focusing on steady conditions near a hillslope crest, where particles steadily move into and through a soil mantle with fixed thickness in the presence of erosion. Our objective is to clarify consequences of the geometry of the particle trajectories and disturbance‐driven mixing in relation to the arrangement of the surfaces through which the particles enter and leave the soil element. We introduce an Eulerian‐Lagrangian description of particle motions to characterize effects of a nonuniform (two‐dimensional) mean motion with superimposed depth‐dependent mixing. With weak mixing, the forms and moments of the probability distributions of particle residence times and ages are distinct and are largely controlled by the geometry of the mean particle motion within the soil element. The average particle age is systematically less than the average residence time. These distributions converge to exponential forms with equal means only in the idealized limit of a “well‐mixed” system. The analysis provides the foundation for considering particle weathering and chemical losses in relation to residence times and ages and for describing the spatiotemporal structure of tracers, for example, cosmogenic nuclide concentrations and optically stimulated luminescence particle ages, in relation to what these reveal about particle mixing.
Airborne Remote Sensing of Wave Propagation in the Marginal Ice Zone
Authors: Sutherland Peter , Brozena John , Rogers W. Erick , Doble Martin , Wadhams Peter
Published: May 2018

Airborne scanning lidar was used to measure the evolution of the surface wave field in the marginal ice zone (MIZ) during two separate wave events in the Beaufort Sea in October 2015. The lidar data consisted of a 2‐D field of surface elevation with horizontal resolutions between 17 and 33 cm, over a swath approximately 150‐220 m wide, centred on the ground track of the aircraft. Those data were used to compute directional wavenumber spectra of the surface wave field. Comparison with nearly collocated buoy data found the lidar and buoy measurements to be generally consistent. During the first event, waves traveling from open water into the ice were attenuated by the ice. The low spectral spreading and
spectral dependence of the attenuation was consistent with dissipative models that treat sea ice as a highly viscous fluid floating on a less viscous ocean. Upper‐ocean eddy viscosities calculated using that model were found to be significantly lower than those from previous work. The second event was in off‐ice winds and cold temperatures, allowing measurement of the wave fetch relation in ice‐forming conditions. The wave growth rate was found to be slightly higher than previous measurements under unstable atmospheric conditions without ice formation. Comparison with WAVEWATCH III model output highlighted the importance of accurate ice information and fine geographic computational resolution when making predictions near the ice edge. Finally, the very short scales over which the wave field was observed to evolve in the MIZ are discussed.
Light-driven transformable optical agent with adaptive functions for boosting cancer surgery outcomes
Authors: Qi Ji , Chen Chao , Zhang Xiaoyan , Hu Xianglong , Ji Shenglu , Kwok Ryan T. K. , Lam Jacky W. Y. , Ding Dan , Tang Ben Zhong
Published: May 2018

Fluorescence and photoacoustic imaging have different advantages in cancer diagnosis; however, combining effects in one agent normally requires a trade-off as the mechanisms interfere. Here, based on rational molecular design, we introduce a smart organic nanoparticle whose absorbed excitation energy can be photo-switched to the pathway of thermal deactivation for photoacoustic imaging, or to allow opposed routes for fluorescence imaging and photodynamic therapy. The molecule is made of a dithienylethene (DTE) core with two surrounding 2-(1-(4-(1,2,2-triphenylvinyl)phenyl)ethylidene)malononitrile (TPECM) units (DTE-TPECM). The photosensitive molecule changes from a ring-closed, for photoacoustic imaging, to a ring-opened state for fluorescence and photodynamic effects upon an external light trigger. The nanoparticles’ photoacoustic and fluorescence imaging properties demonstrate the advantage of the switch. The use of the nanoparticles improves the outcomes of in vivo cancer surgery using preoperative photoacoustic imaging and intraoperative fluorescent visualization/photodynamic therapy of residual tumours to ensure total tumour removal.
Screening for the anti-inflammation quality markers of Xiaojin Pills based on HPLC-MS/MS method, COX-2 inhibition test and protein interaction network
Authors: Xiong Xi , He Ya-nan , Feng Bi , Pan Yuan , Zhang Hai-zhu , Ke Xiu-mei , Zhang Yi , Yang Ming , Han Li , Zhang Ding-kun
Published: May 2018

Nowadays, breast disorders seriously affect women’s health in an increasing number. In China, Xiaojin Pills are commonly used in the treatment of breast diseases. Doctors have concluded that the combined use of Xiaojin Pills with conventional therapy can significantly improve the efficacy with fewer side effects. However, the prescription of Xiaojin Pills is complicated and their quality control methods cannot completely ensure the quality of Xiaojin Pills. On the basis of its mechanism, our study combined chemical evaluation and biological evaluation to identify the anti-inflammatory markers of Xiaojin Pills. In this manuscript, 13 compounds in Xiaojin Pills were quantified. At the same time, the cyclooxygenase-2 inhibition rates of different Xiaojin Pills were measured and the possible markers were screened by spectrum-effect relationship. Further, anti-inflammatory activities of markers were verified and protein interaction network was analyzed, identifying the components of Protocatechuate, Beta-Boswellic acid and Levistilide A as the anti-inflammatory quality markers of Xiaojin Pills. We hope our studies can provide a scientific theoretical basis for accurately quality control of Xiaojin Pills and reasonable suggestions for pharmaceutical companies and new ideas for the quality control of other medicines.
Genotype I of Japanese Encephalitis Virus Virus-like Particles Elicit Sterilizing Immunity against Genotype I and III Viral Challenge in Swine
Authors: Fan Yi-Chin , Chen Jo-Mei , Lin Jen-Wei , Chen Yi-Ying , Wu Guan-Hong , Su Kuan-Hsuan , Chiou Ming-Tang , Wu Shang-Rung , Yin Ji-Hang , Liao Jiunn-Wang , Chang Gwong-Jen J. , Chiou Shyan-Song
Published: May 2018

Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.
Improvement of the activity of the anti-HIV-1 integrase aptamer T30175 by introducing a modified thymidine into the loops
Authors: Virgilio Antonella , Amato Teresa , Petraccone Luigi , Esposito Francesca , Grandi Nicole , Tramontano Enzo , Romero Raquel , Haider Shozeb , Gomez-Monterrey Isabel , Novellino Ettore , Mayol Luciano , Esposito Veronica , Galeone Aldo
Published: May 2018

In this paper, we report our investigations on analogues of the anti-human immunodeficiency virus type 1 (HIV-1) integrase (IN) aptamer T30175 in which the individual thymidines forming the loops were replaced by 5-hydroxymethyl-2′-deoxyuridine residues (H). Circular dichroism, nuclear magnetic resonance and gel electrophoresis investigations clearly indicated that all the modified aptamers preserve the ability to form the original 5′-5′ end-stacked head-to-head dimeric G-quadruplex structure, in which each G-quadruplex adopts a parallel arrangement and is characterized by three G-tetrads, three propeller loops and one bulge-loop. All the modified aptamers were tested in an IN inhibition LEDGF-independent assay. While the modified aptamers INTB-H13 and INTB-H17 showed IC50 values comparable with that of the parent aptamer (INTB-nat), analogues INTB-H2, INTB-H5 and, to a lesser extent, INTB-H9 showed a higher ability to inhibit the HIV IN than the unmodified aptamer. Molecular modelling studies evaluating the aptamer/HIV IN interaction highlighted the ability of the modified thymidines to establish several contacts with the target protein. All the data point to the importance of loops in the aptamer/target interaction and suggest that the site-specific replacement of loop residues with commercially available analogues can be considered a straightforward strategy to improve the biological activities of several G-quadruplex aptamers.
Precocious deposition of perineuronal nets on Parvalbumin inhibitory neurons transplanted into adult visual cortex
Authors: Bradshaw Karen P. , Figueroa Velez Dario X. , Habeeb Mariyam , Gandhi Sunil P.
Published: May 2018

The end of the critical period for primary visual cortex (V1) coincides with the deposition of perineuronal nets (PNN) onto Parvalbumin (PV) inhibitory neurons. Recently, we found that transplantation of embryonic inhibitory neurons into adult V1 reinstates a new critical period. Here we used Wisteria Floribunda Agglutinin (WFA) staining to compare the deposition of PNNs onto neurons during normal development and following transplantation at equivalent cell ages. In accord with previous findings, PV and PNN expression increases from negligible levels at postnatal day 14 (P14) to mature levels by P70. In contrast to P14, PNNs are found on transplanted PV neurons by 21 days after transplantation and persist to 105 days after transplantation. This precocious deposition was specific to PV neurons and excluded transplanted neurons expressing Somatostatin. Notably, the onset of PV expression in transplanted inhibitory neurons follows the timing of PV expression in juvenile V1. Moreover, transplantation has no discernible effect on host PNNs. The precocious deposition of PNNs onto transplanted PV neurons suggests that PNN expression identified by WFA does not reflect neuronal maturity and may be an inaccurate marker for transplant-induced plasticity of cortical circuits.
Peripheral N-methyl-D-aspartate receptor localization and role in gastric acid secretion regulation: immunofluorescence and pharmacological studies
Authors: Golovynska Iuliia , Beregova Tatiana V. , Falalyeyeva Tatiana M. , Stepanova Ludmila I. , Golovynskyi Sergii , Qu Junle , Ohulchanskyy Tymish Y.
Published: May 2018

The enteric nervous system (ENS) and a glutamate receptor (GluR), N-methyl-D-aspartate receptor (NMDAR), participate in gastric acid secretion (GAS) regulation. NMDARs are localized in different stomach cells; however, knowledge of NMDAR expression and function in the ENS is limited. In the present study, we clarified the types of stomach cells that express the NMDARs that are involved in GAS regulation. The pharmacological method of isolated stomach perfusion by Ghosh and Shild combined with direct mapping of NMDARs by fluorescence microscopy in the rat stomach was employed. By immunofluorescence labeling with an anti-NMDA-NR1 antibody, NMDARs were found to be highly expressed in nerve cells of the submucosal and myenteric plexuses in the stomach. The exact localization of the NMDARs relevant to GAS and its mechanism of action were determined by stimulating different receptors of neuronal and stomach cells using specific secretagogues for NMDA and by selectively blocking those receptors. NMDARs relevant to GAS stimulation are mainly localized in cholinergic interneurons; however, all of the nerve cells of the submucosal ganglia are involved in the stimulating process. In addition, the NMDARs in parietal cells are involved in gastric acid inhibition via influencing H2-histamine receptors.
Altered attentional control over the salience network in complex regional pain syndrome
Authors: Kim Jungyoon , Kang Ilhyang , Chung Yong-An , Kim Tae-Suk , Namgung Eun , Lee Suji , Oh Jin Kyoung , Jeong Hyeonseok S. , Cho Hanbyul , Kim Myeong Ju , Kim Tammy D. , Choi Soo Hyun , Lim Soo Mee , Lyoo In Kyoon , Yoon Sujung
Published: May 2018

The degree and salience of pain have been known to be constantly monitored and modulated by the brain. In the case of maladaptive neural responses as reported in centralized pain conditions such as complex regional pain syndrome (CRPS), the perception of pain is amplified and remains elevated even without sustained peripheral pain inputs. Given that the attentional state of the brain greatly influences the perception and interpretation of pain, we investigated the role of the attention network and its dynamic interactions with other pain-related networks of the brain in CRPS. We examined alterations in the intra- and inter-network functional connectivities in 21 individuals with CRPS and 49 controls. CRPS-related reduction in intra-network functional connectivity was found in the attention network. Individuals with CRPS had greater inter-network connectivities between the attention and salience networks as compared with healthy controls. Furthermore, individuals within the CRPS group with high levels of pain catastrophizing showed greater inter-network connectivities between the attention and salience networks. Taken together, the current findings suggest that these altered connectivities may be potentially associated with the maladaptive pain coping as found in CRPS patients.
Isolated terawatt attosecond hard X-ray pulse generated from single current spike
Authors: Shim Chi Hyun , Parc Yong Woon , Kumar Sandeep , Ko In Soo , Kim Dong Eon
Published: May 2018

Isolated terawatt (TW) attosecond (as) hard X-ray pulse is greatly desired for four-dimensional investigations of natural phenomena with picometer spatial and attosecond temporal resolutions. Since the demand for such sources is continuously increasing, the possibility of generating such pulse by a single current spike without the use of optical or electron delay units in an undulator line is addressed. The conditions of a current spike (width and height) and a modulation laser pulse (wavelength and power) is also discussed. We demonstrate that an isolated TW-level as a hard X-ray can be produced by a properly chosen single current spike in an electron bunch with simulation results. By using realistic specifications of an electron bunch of the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), we show that an isolated, >1.0 TW and ~36 as X-ray pulse at 12.4 keV can be generated in an optimized-tapered undulator line. This result opens a new vista for current XFEL operation: the attosecond XFEL.
Anticancer activity and antibody-dependent cell-mediated cytotoxicity of novel anti-nucleolin antibodies
Authors: Romano Sofia , Moura Vera , Simões Sérgio , Moreira João Nuno , Gonçalves João
Published: May 2018

Nucleolin arises as a relevant target for cancer therapy, as it is overexpressed at the surface of cancer and angiogenic endothelial cells thus enabling a dual cellular targeting strategy. Immunotherapeutic strategies, albeit of proven therapeutic relevance, have been scarcely explored against this target. Therefore, this work aimed at engineering an anti-nucleolin VHH-based antibody capable of triggering anticancer immune responses. Herein, anti-nucleolin VHHs have been generated upon grafting F3 peptide-derived nucleolin-binding sequences onto a VHH CDR1 or CDR3. One of these nucleolin-binding CDR3-grafted VHH was subsequently fused to a human IgG1 Fc region, enabling a significant antibody-dependent cell-mediated cytotoxicity (ADCC). The generated anti-nucleolin VHH revealed increased binding and antiproliferative effects against cancer cells, relative to the parental VHH, while the VHH-Fc counterpart presented increased cytotoxicity relative to the corresponding VHH. This VHH-Fc also triggered an ADCC effect, in the nanomolar range, against a nucleolin-overexpressing cancer cell line. This effect was evidenced by a 2 or 1.7-fold increase of cell death, in the presence of PBMCs, relative to the parental VHH-Fc or the VHH counterpart, respectively. Overall, these formats represent the first anti-nucleolin VHHs and the first anti-nucleolin antibody with ADCC activity that have been successfully developed.
A DFA-based bivariate regression model for estimating the dependence of PM2.5 among neighbouring cities
Authors: Wang Fang , Wang Lin , Chen Yuming
Published: May 2018

On the basis of detrended fluctuation analysis (DFA), we propose a new bivariate linear regression model. This new model provides estimators of multi-scale regression coefficients to measure the dependence between variables and corresponding variables of interest with multi-scales. Numerical tests are performed to illustrate that the proposed DFA-bsaed regression estimators are capable of accurately depicting the dependence between the variables of interest and can be used to identify different dependence at different time scales. We apply this model to analyze the PM2.5 series of three adjacent cities (Beijing, Tianjin, and Baoding) in Northern China. The estimated regression coefficients confirmed the dependence of PM2.5 among the three cities and illustrated that each city has different influence on the others at different seasons and at different time scales. Two statistics based on the scale-dependent t-statistic and the partial detrended cross-correlation coefficient are used to demonstrate the significance of the dependence. Three new scale-dependent evaluation indices show that the new DFA-based bivariate regression model can provide rich information on studied variables.
Transcriptome and Co-Expression Network Analyses Identify Key Genes Regulating Nitrogen Use Efficiency in Brassica juncea L.
Authors: Goel Parul , Sharma Nitesh Kumar , Bhuria Monika , Sharma Vishal , Chauhan Rohit , Pathania Shivalika , Swarnkar Mohit Kumar , Chawla Vandna , Acharya Vishal , Shankar Ravi , Singh Anil Kumar
Published: May 2018

Nitrate is the main source of inorganic nitrogen for plants, which also act as signaling molecule. Present study was aimed to understand nitrate regulatory mechanism in Brassica juncea cultivars, with contrasting nitrogen-use-efficiency (NUE) viz. Pusa Bold (PB, high-NUE) and Pusa Jai Kisan (PJK, low-NUE), employing RNA-seq approach. A total of 4031, 3874 and 3667 genes in PB and 2982, 2481 and 2843 genes in PJK were differentially expressed in response to early, low (0.25 mM KNO3), medium (2 mM KNO3) and high (4 mM KNO3) nitrate treatments, respectively, as compared to control (0 mM KNO3). Genes of N-uptake (NRT1.1, NRT1.8, and NRT2.1), assimilation (NR1, NR2, NiR, GS1.3, and Fd-GOGAT) and remobilization (GDH2, ASN2–3 and ALaT) were highly-upregulated in PB than in PJK in response to early nitrate treatments. We have also identified transcription factors and protein kinases that were rapidly induced in response to nitrate, suggesting their involvement in nitrate-mediated signaling. Co-expression network analysis revealed four nitrate specific modules in PB, enriched with GO terms like, “Phenylpropanoid pathway”, “Nitrogen compound metabolic process” and “Carbohydrate metabolism”. The network analysis also identified HUB transcription factors like mTERF, FHA, Orphan, bZip and FAR1, which may be the key regulators of nitrate-mediated response in B. juncea.
Novel method for rapid toxicity screening of magnetic nanoparticles
Authors: Erofeev A. , Gorelkin P. , Garanina A. , Alova A. , Efremova M. , Vorobyeva N. , Edwards C. , Korchev Y. , Majouga A.
Published: May 2018

Iron oxide nanoparticles have attracted a great deal of research interest and have been widely used in bioscience and clinical research including as contrast agents for magnetic resonance imaging, hyperthermia and magnetic field assisted radionuclide therapy. It is therefore important to develop methods, which can provide high-throughput screening of biological responses that can predict toxicity. The use of nanoelectrodes for single cell analysis can play a vital role in this process by providing relatively fast, comprehensive, and cost-effective assessment of cellular responses. We have developed a new method for in vitro study of the toxicity of magnetic nanoparticles (NP) based on the measurement of intracellular reactive oxygen species (ROS) by a novel nanoelectrode. Previous studies have suggested that ROS generation is frequently observed with NP toxicity. We have developed a stable probe for measuring intracellular ROS using platinized carbon nanoelectrodes with a cavity on the tip integrated into a micromanipulator on an upright microscope. Our results show a significant difference for intracellular levels of ROS measured in HEK293 and LNCaP cancer cells before and after exposure to 10 nm size iron oxide NP. These results are markedly different from ROS measured after cell incubation with the same concentration of NP using standard methods where no differences have been detected. In summary we have developed a label-free method for assessing nanoparticle toxicity using the rapid (less than 30 minutes) measurement of ROS with a novel nanoelectrode.
Sea Lions Develop Human-like Vernix Caseosa Delivering Branched Fats and Squalene to the GI Tract
Authors: Wang Dong Hao , Ran-Ressler Rinat , St Leger Judy , Nilson Erika , Palmer Lauren , Collins Richard , Brenna J. Thomas
Published: May 2018

Vernix caseosa, the white waxy coating found on newborn human skin, is thought to be a uniquely human substance. Its signature characteristic is exceptional richness in saturated branched chain fatty acids (BCFA) and squalene. Vernix particles sloughed from the skin suspended in amniotic fluid are swallowed by the human fetus, depositing BCFA/squalene throughout the gastrointestinal (GI) tract, thereby establishing a unique microbial niche that influences development of nascent microbiota. Here we show that late-term California sea lion (Zalophus californianus) fetuses have true vernix caseosa, delivering BCFA and squalene to the fetal GI tract thereby recapitulating the human fetal gut microbial niche. These are the first data demonstrating the production of true vernix caseosa in a species other than Homo sapiens. Its presence in a marine mammal supports the hypothesis of an aquatic habituation period in the evolution of modern humans.
Xiaoshuan enteric-coated capsule alleviates cognitive impairment by enhancing hippocampal glucose metabolism, hemodynamics and neuroplasticity of rat with chronic cerebral hypoperfusion
Authors: Li Man-zhong , Zhang Yi , Zou Hai-yan , Wang Ya-li , Cheng Brian-Chi Yan , Wang Lei , Zhang Qiu-xia , Lei Jian-feng , Zhao Hui
Published: May 2018

Chronic cerebral hypoperfusion (CCH) is identified as a critical risk factor of dementia in patients with cerebrovascular disease. Xiaoshuan enteric-coated capsule (XSECC) is a compound Chinese medicine approved by Chinese State Food and Drug Administration for promoting brain remodeling and plasticity after stroke. The present study aimed to explore the potential of XSECC to improve cognitive function after CCH and further investigate the underlying mechanisms. CCH was induced by bilateral common carotid artery occlusion (BCCAO) in rats. XSECC (420 or 140 mg/kg) treatment remarkably reversed BCCAO-induced cognitive deficits. Notably, after XSECC treatment, magnetic resonance angiography combined with arterial spin labeling noninvasively demonstrated significantly improved hippocampal hemodynamics, and 18F-FDG PET/CT showed enhanced hippocampal glucose metabolism. In addition, XSECC treatment markedly alleviated neuropathologies and improved neuroplasticity in the hippocampus. More importantly, XSECC treatment facilitated axonal remodeling by regulating the phosphorylation of axonal growth related proteins including protein kinase B (AKT), glycogen synthase kinase-3β (GSK-3β) and collapsin response mediator protein-2 (CRMP2) in the hippocampus. Taken together, the present study demonstrated the beneficial role of XSECC in alleviating BCCAO-induced cognitive deficits by enhancing hippocampal glucose metabolism, hemodynamics and neuroplasticity, suggesting that XSECC could be a useful strategy in cerebral hypoperfusion state and dementia.
Facile production of nanocomposites of carbon nanotubes and polycaprolactone with high aspect ratios with potential applications in drug delivery
Authors: Niezabitowska Edyta , Smith Jessica , Prestly Mark R. , Akhtar Riaz , von Aulock Felix W. , Lavallée Yan , Ali-Boucetta Hanene , McDonald Tom O.
Published: May 2018

Facile route to polymer carbon nanotube nanocomposites.
Lead isotope ratios in lead-glazed ceramics determined by laser ablation multi-collector inductively coupled plasma mass spectrometry for discriminating purpose
Authors: Zong Chunlei , Bao Zhian , Ran Wangli , Ling Xue , Chen Lu , Chen Kaiyun , Yuan Honglin
Published: May 2018

Herein, the potential of laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) for the determination of Pb isotopes of lead-glazed ceramics has been investigated.
Catalytic asymmetric synthesis of spirooxindoles: recent developments
Authors: Mei Guang-Jian , Shi Feng
Published: May 2018

The past four years have witnessed significant developments in the field of the catalytic asymmetric synthesis of spirooxindoles, and this feature article outlines the recent progress in this area, including the contributions of our group. This article is divided into sections according to the size and type of the generated spiro-ring fused at the C3-position of the oxindole core.
A quasi-solid-state and self-powered biosupercapacitor based on flexible nanoporous gold electrodes
Authors: Xiao Xinxin , Magner Edmond
Published: May 2018

A quasi-solid-state and flexible biofuel cell using a hydrogel electrolyte preloaded with sugar as a fuel is described.
Using neutrons, X-rays and nuclear magnetism to determine the role of transition metal oxide inclusions on both glass structure and stability in automotive glass enamels
Authors: Bowron Daniel T. , Booth Jonathan , Barrow Nathan S. , Sutton Patricia , Johnson Simon R.
Published: May 2018

Low levels of transition metal oxides in alkali borosilicate glass systems can drastically influence crystallisation and phase separation properties.
Binary ZnO/Zn–Cr nanospinel catalysts prepared by a hydrothermal method for isobutanol synthesis from syngas
Authors: Gao Xiaofeng , Wu Yingquan , Zhang Tao , Wang Liyan , Li Xiaoli , Xie Hongjuan , Tan Yisheng
Published: May 2018

A series of binary ZnO/Zn–Cr nanospinel catalysts were prepared by a hydrothermal method and applied in direct synthesis of isobutanol from syngas, during which the effect of the hydrothermal time/temperature on their catalytic performance in the isobutanol synthesis has been investigated at 400 °C and 10 MPa.
A metal–organic framework based on a custom-designed diisophthalate ligand exhibiting excellent hydrostability and highly selective adsorption of C2H2and CO2over CH4
Authors: Wang Yao , He Minghui , Gao Xiaoxia , Li Saidan , He Yabing
Published: May 2018

The ligand truncation strategy was employed to devise a novel bent diisophthalate ligand which was used to construct a copper-based MOF exhibiting highly selective C2H2/CH4and CO2/CH4separations.
Heteroleptic samarium(iii) halide complexes probed by fluorescence-detected L3-edge X-ray absorption spectroscopy
Authors: Goodwin Conrad A. P. , Réant Benjamin L. L. , Kragskow Jon G. C. , DiMucci Ida M. , Lancaster Kyle M. , Mills David P. , Sproules Stephen
Published: May 2018

The novel series of heteroleptic Sm(iii) halide complexes provides the backdrop for a fluorescence-detected Lα1X-ray absorption spectroscopic study.
Occurrence, impact variables and potential risk of PPCPs and pesticides in a drinking water reservoir and related drinking water treatment plants in the Yangtze Estuary
Authors: Xu Cong , Chen Lei , You Luhua , Xu Zheng , Ren Long-Fei , Yew-Hoong Gin Karina , He Yiliang , Kai Weizhi
Published: May 2018

PPCPs and pesticides have been documented throughout the world over the years, yet relatively little is known about the factors affecting their spatial distribution and temporal change in order to know their potential risk to the ecosystem or human health in the future.
Trace metals in oysters: molecular and cellular mechanisms and ecotoxicological impacts
Authors: Wang Wen-Xiong , Meng Jie , Weng Nanyan
Published: May 2018

Oysters are important benthic bivalves in coastal and estuarine environments.
Robust open cellular porous polymer monoliths made from cured colloidal gels of latex particles
Authors: Desire Christopher T. , Lotierzo Andrea , Arrua R. Dario , Hilder Emily F. , Bon Stefan A. F.
Published: May 2018

Preparation of polymer monoliths from the coagulation of particles, synthesized by soap-free emulsion polymerisation, using water as the only solvent.
Direct observation of dynamical magnetization reversal process governed by shape anisotropy in single NiFe2O4 nanowire
Authors: Zhang Junli , Zhu Shimeng , Li Hongli , Zhu Liu , Hu Yang , Xia Weixing , Zhang Xixiang , Peng Yong , Fu Jiecai
Published: May 2018

Direct observation of dynamical magnetization reversal process in a NiFe2O4 nanowire reveals the domination of shape anisotropy on its magnetic behavior.
iRGD-decorated reduction-responsive nanoclusters for targeted drug delivery
Authors: Hu Hang , Wan Jiangling , Huang Xuetao , Tang Yuxiang , Xiao Chen , Xu Huibi , Yang Xiangliang , Li Zifu
Published: May 2018

iRGD decorated reduction-responsive disintegratable nanoclusters (NCs) were prepared as a novel nanoplatform for efficient intracellular drug delivery.
Fingerprint profiling of polysaccharides from different parts of lotus root varieties
Authors: Wang Hong-Xun , Yi Yang , Sun Jie , Lamikanra Olusola , Min Ting
Published: May 2018

Thirty-nine polysaccharides isolated from lotus roots were characterized with fingerprint and chemometrics analyses to explore their similarity and diversity.
Enhancing the conversion of ethyl levulinate to γ-valerolactone over Ru/UiO-66 by introducing sulfonic groups into the framework
Authors: Yang Jie , Huang Wenjuan , Liu Yongsheng , Zhou Tao
Published: May 2018

Ru/UiO-66 modified with –SO3H groups shows good acidic catalytic performance while also showing hydrogenation activity towards CO bonds, thus improving the overall transformation of EL to GVL due to the presence of strong Brønsted acid sites.
Electrically and electrohydrodynamically driven phase transition and structural color switching of oligomer tethered 2D colloid
Authors: Masud Aurangzeb Rashid , Hong Seung-Ho , Shen Tian-Zi , Shahzad Amir , Song Jang-Kun
Published: May 2018

The structural color in 2D nanoparticle colloid photonic crystal can be switched by using both electrohydrodynamic flow and Maxwell–Wagner polarization.
Multiple roles of aryloxide leaving groups in enantioselective annulations employing α,β-unsaturated acyl ammonium catalysis
Authors: Greenhalgh Mark D. , Qu Shen , Slawin Alexandra M. Z. , Smith Andrew D.
Published: May 2018

Aryloxides play an essential role as: (i) leaving group; (ii) Brønsted base; and (iii) Lewis base; in enantioselective isothiourea-catalysed annulations.