Low LET protons focused to submicrometer shows enhanced radiobiological effectiveness

International Nuclear Information System (INIS)

Schmid, T E; Zlobinskaya, O; Michalski, D; Molls, M; Multhoff, G; Greubel, C; Hable, V; Girst, S; Siebenwirth, C; Dollinger, G; Schmid, E

2012-01-01

This study shows that enhanced radiobiological effectiveness (RBE) values can be generated focusing low linear energy transfer (LET) radiation and thus changing the microdose distribution. 20 MeV protons (LET = 2.65 keV µm −1 ) are focused to submicrometer diameter at the ion microprobe superconducting nanoprobe for applied nuclear (Kern) physics experiments of the Munich tandem accelerator. The RBE values, as determined by measuring micronuclei (RBE MN = 1.48 ± 0.07) and dicentrics (RBE D = 1.92 ± 0.15), in human–hamster hybrid (A L ) cells are significantly higher when 117 protons were focused to a submicrometer irradiation field within a 5.4 × 5.4 µm 2 matrix compared to quasi homogeneous in a 1 × 1 µm 2 matrix applied protons (RBE MN = 1.28 ± 0.07; RBE D = 1.41 ± 0.14) at the same average dose of 1.7 Gy. The RBE values are normalized to standard 70 kV (dicentrics) or 200 kV (micronuclei) x-ray irradiation. The 117 protons applied per point deposit the same amount of energy like a 12 C ion with 55 MeV total energy (4.48 MeV u −1 ). The enhancements are about half of that obtained for 12 C ions (RBE MN = 2.20 ± 0.06 and RBE D = 3.21 ± 0.10) and they are attributed to intertrack interactions of the induced damages. The measured RBE values show differences from predictions of the local effect model (LEM III) that is used to calculate RBE values for irradiation plans to treat tumors with high LET particles. (paper)

Adaptive memory: young children show enhanced retention of fitness-related information.

Science.gov (United States)

Aslan, Alp; Bäuml, Karl-Heinz T

2012-01-01

Evolutionary psychologists propose that human cognition evolved through natural selection to solve adaptive problems related to survival and reproduction, with its ultimate function being the enhancement of reproductive fitness. Following this proposal and the evolutionary-developmental view that ancestral selection pressures operated not only on reproductive adults, but also on pre-reproductive children, the present study examined whether young children show superior memory for information that is processed in terms of its survival value. In two experiments, we found such survival processing to enhance retention in 4- to 10-year-old children, relative to various control conditions that also required deep, meaningful processing but were not related to survival. These results suggest that, already in very young children, survival processing is a special and extraordinarily effective form of memory encoding. The results support the functional-evolutionary proposal that young children's memory is "tuned" to process and retain fitness-related information. Copyright © 2011 Elsevier B.V. All rights reserved.

Spatiotemporally enhancing time-series DMSP/OLS nighttime light imagery for assessing large-scale urban dynamics

Science.gov (United States)

Xie, Yanhua; Weng, Qihao

2017-06-01

Accurate, up-to-date, and consistent information of urban extents is vital for numerous applications central to urban planning, ecosystem management, and environmental assessment and monitoring. However, current large-scale urban extent products are not uniform with respect to definition, spatial resolution, temporal frequency, and thematic representation. This study aimed to enhance, spatiotemporally, time-series DMSP/OLS nighttime light (NTL) data for detecting large-scale urban changes. The enhanced NTL time series from 1992 to 2013 were firstly generated by implementing global inter-calibration, vegetation-based spatial adjustment, and urban archetype-based temporal modification. The dataset was then used for updating and backdating urban changes for the contiguous U.S.A. (CONUS) and China by using the Object-based Urban Thresholding method (i.e., NTL-OUT method, Xie and Weng, 2016b). The results showed that the updated urban extents were reasonably accurate, with city-scale RMSE (root mean square error) of 27 km2 and Kappa of 0.65 for CONUS, and 55 km2 and 0.59 for China, respectively. The backdated urban extents yielded similar accuracy, with RMSE of 23 km2 and Kappa of 0.63 in CONUS, while 60 km2 and 0.60 in China. The accuracy assessment further revealed that the spatial enhancement greatly improved the accuracy of urban updating and backdating by significantly reducing RMSE and slightly increasing Kappa values. The temporal enhancement also reduced RMSE, and improved the spatial consistency between estimated and reference urban extents. Although the utilization of enhanced NTL data successfully detected urban size change, relatively low locational accuracy of the detected urban changes was observed. It is suggested that the proposed methodology would be more effective for updating and backdating global urban maps if further fusion of NTL data with higher spatial resolution imagery was implemented.

Enhancement of large fluctuations to extinction in adaptive networks

Science.gov (United States)

Hindes, Jason; Schwartz, Ira B.; Shaw, Leah B.

2018-01-01

During an epidemic, individual nodes in a network may adapt their connections to reduce the chance of infection. A common form of adaption is avoidance rewiring, where a noninfected node breaks a connection to an infected neighbor and forms a new connection to another noninfected node. Here we explore the effects of such adaptivity on stochastic fluctuations in the susceptible-infected-susceptible model, focusing on the largest fluctuations that result in extinction of infection. Using techniques from large-deviation theory, combined with a measurement of heterogeneity in the susceptible degree distribution at the endemic state, we are able to predict and analyze large fluctuations and extinction in adaptive networks. We find that in the limit of small rewiring there is a sharp exponential reduction in mean extinction times compared to the case of zero adaption. Furthermore, we find an exponential enhancement in the probability of large fluctuations with increased rewiring rate, even when holding the average number of infected nodes constant.

Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate.

Science.gov (United States)

Zhang, Huanhuan; Xu, Lin; Xu, Yabo; Huang, Gang; Zhao, Xueyu; Lai, Yuqing; Shi, Tongfei

2016-12-06

We study the enhanced dewetting of ultrathin Polystyrene (PS)/Poly (methyl methacrylate) (PMMA) blend films in a mixed solution, and reveal the dewetting can act as a simple and effective method to fabricate large-area surface-enhanced Raman scattering (SERS) substrate. A bilayer structure consisting of under PMMA layer and upper PS layer forms due to vertical phase separation of immiscible PS/PMMA during the spin-coating process. The thicker layer of the bilayer structure dominates the dewetting structures of PS/PMMA blend films. The diameter and diameter distribution of droplets, and the average separation spacing between the droplets can be precisely controlled via the change of blend ratio and film thickness. The dewetting structure of 8 nm PS/PMMA (1:1 wt%) blend film is proved to successfully fabricate large-area (3.5 cm × 3.5 cm) universal SERS substrate via deposited a silver layer on the dewetting structure. The SERS substrate shows good SERS-signal reproducibility (RSD dewetting of polymer blend films broadens the application of dewetting of polymer films, especially in the nanotechnology, and may open a new approach for the fabrication of large-area SERS substrate to promote the application of SERS substrate in the rapid sensitive detection of trace molecules.

Enhancing Performance of Large-Area Organic Solar Cells with Thick Film via Ternary Strategy.

Science.gov (United States)

Zhang, Jianqi; Zhao, Yifan; Fang, Jin; Yuan, Liu; Xia, Benzheng; Wang, Guodong; Wang, Zaiyu; Zhang, Yajie; Ma, Wei; Yan, Wei; Su, Wenming; Wei, Zhixiang

2017-06-01

Large-scale fabrication of organic solar cells requires an active layer with high thickness tolerability and the use of environment-friendly solvents. Thick films with high-performance can be achieved via a ternary strategy studied herein. The ternary system consists of one polymer donor, one small molecule donor, and one fullerene acceptor. The small molecule enhances the crystallinity and face-on orientation of the active layer, leading to improved thickness tolerability compared with that of a polymer-fullerene binary system. An active layer with 270 nm thickness exhibits an average power conversion efficiency (PCE) of 10.78%, while the PCE is less than 8% with such thick film for binary system. Furthermore, large-area devices are successfully fabricated using polyethylene terephthalate (PET)/Silver gride or indium tin oxide (ITO)-based transparent flexible substrates. The product shows a high PCE of 8.28% with an area of 1.25 cm 2 for a single cell and 5.18% for a 20 cm 2 module. This study demonstrates that ternary organic solar cells exhibit great potential for large-scale fabrication and future applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical study by large-eddy simulation on effects and mechanism of air-cooling enhancing technologies

International Nuclear Information System (INIS)

Tamura, Akinori; Kawamura, Toshinori; Ishida, Naoyuki; Kitou, Kazuaki

2014-01-01

Learning from the lessons of the Fukushima Daiichi nuclear incident in which a long-term station black-out occurred, we have been developing an air-cooling system for boiling water reactors that can operate without electricity for a virtually indefinite time. Improvement in the heat transfer performance of air-cooling is key to the development of the air-cooling system. We developed air-cooling enhancing technologies for the air-cooling system by using heat transfer fins, turbulence-enhancing ribs and a micro-fabrication surface. In our previous study, the performance of these air-cooling enhancing technologies was evaluated by heat transfer tests using a single pipe of the air-cooling heat exchanger. To achieve further improvement of the heat transfer performance, it is important to understand the mechanism of the air-cooling enhancing technologies. In this study, we used the numerical analysis which is based on the filtered incompressible Navier-Stokes equation and the filtered energy equation with the large-eddy simulation in order to investigate the effects and the mechanism of the developed air-cooling enhancing technologies. We found that the analysis results agreed well with the experimental results and the empirical formula results. The heat transfer enhancement mechanism of the heat transfer fin is due to an increase in the heat transfer area. Due to a decrease in the flow velocity at the base of the fins, the increase in the Nusselt number was approximately 15% smaller than the estimated value from the area increase. In the heat transfer enhancement by the turbulence-enhancing ribs, the unsteady behavior of the large-scale vortex generated by the flow separation plays an important role. The enhancement ratio of the Nusselt number by the micro-fabrication surface can be explained by the apparent thermal conductivity. The Nusselt number was increased 4-8% by the micro-fabrication surface. The effect of the micro-fabrication surface is increased by applying

A large scale test of the gaming-enhancement hypothesis

Directory of Open Access Journals (Sweden)

Andrew K. Przybylski

2016-11-01

Full Text Available A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis, has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people’s gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work.

A large scale test of the gaming-enhancement hypothesis.

Science.gov (United States)

Przybylski, Andrew K; Wang, John C

2016-01-01

A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis , has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people's gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work.

The Sommerfeld enhancement in the scotogenic model with large electroweak scalar multiplets

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Talal Ahmed [Department of Physics, University of Dhaka, P.O. Box 1000, Dhaka (Bangladesh); Nasri, Salah, E-mail: talal@du.ac.bd, E-mail: snasri@uaeu.ac.ae [Department of Physics, UAE University, P.O. Box 17551, Al-Ain (United Arab Emirates)

2017-01-01

We investigate the Sommerfeld enhancement (SE) in the generalized scotogenic model with large electroweak multiplets. We focus on scalar dark matter (DM) candidate of the model and compare DM annihilation cross sections to WW , ZZ , γγ and γ Z at present day in the galactic halo for scalar doublet and its immediate generalization, the quartet in their respective viable regions of parameter space. We find that larger multiplet has sizable Sommerfeld enhanced annihilation cross section compared to the doublet and because of that it is more likely to be constrained by the current H.E.S.S. results and future CTA sensitivity limits.

Large enhancement in photocurrent by Mn doping in CdSe/ZTO quantum dot sensitized solar cells.

Science.gov (United States)

Pimachev, Artem; Poudyal, Uma; Proshchenko, Vitaly; Wang, Wenyong; Dahnovsky, Yuri

2016-09-29

We find a large enhancement in the efficiency of CdSe quantum dot sensitized solar cells by doping with manganese. In the presence of Mn impurities in relatively small concentrations (2.3%) the photoelectric current increases by up to 190%. The average photocurrent enhancement is about 160%. This effect cannot be explained by a light absorption mechanism because the experimental and theoretical absorption spectra demonstrate that there is no change in the absorption coefficient in the presence of the Mn impurities. To explain such a large increase in the injection current we propose a tunneling mechanism of electron injection from the quantum dot LUMO state to the Zn 2 SnO 4 (ZTO) semiconductor photoanode. The calculated enhancement is approximately equal to 150% which is very close to the experimental average value of 160%. The relative discrepancy between the calculated and experimentally measured ratios of the IPCE currents is only 6.25%. For other mechanisms (such as electron trapping, etc.) the remaining 6.25% cannot explain the large change in the experimental IPCE. Thus we have indirectly proved that electron tunneling is the major mechanism of photocurrent enhancement. This work proposes a new approach for a significant improvement in the efficiency of quantum dot sensitized solar cells.

Enhancement of the measurement sensitivity at large aberrations of an optical system of hologram recording

International Nuclear Information System (INIS)

Lyalikov, A.M.

1994-01-01

The method of the measurement sensitivity enhancement with compensation of aberrations based on rewriting object and master holograms recorded on one common carrier using the double-exposure method is considered. Experimental studies indicated the proposed technique of the enhancement of the measurement sensitivity to be promising in the case of large aberrations of an optical system for initial hologram recording. The reconstructed interferograms are presented with enhanced sensitivity of measurements by a factor of 16 characterizing the quality of exit windows of a glass cuvette. 16 refs., 3 figs

Fluorescence enhancement in large-scale self-assembled gold nanoparticle double arrays

International Nuclear Information System (INIS)

Chekini, M.; Bierwagen, J.; Cunningham, A.; Bürgi, T.; Filter, R.; Rockstuhl, C.

2015-01-01

Localized surface plasmon resonances excited in metallic nanoparticles confine and enhance electromagnetic fields at the nanoscale. This is particularly pronounced in dimers made from two closely spaced nanoparticles. When quantum emitters, such as dyes, are placed in the gap of those dimers, their absorption and emission characteristics can be modified. Both processes have to be considered when aiming to enhance the fluorescence from the quantum emitters. This is particularly challenging for dimers, since the electromagnetic properties and the enhanced fluorescence sensitively depend on the distance between the nanoparticles. Here, we use a layer-by-layer method to precisely control the distances in such systems. We consider a dye layer deposited on top of an array of gold nanoparticles or integrated into a central position of a double array of gold nanoparticles. We study the effect of the spatial arrangement and the average distance on the plasmon-enhanced fluorescence. We found a maximum of a 99-fold increase in the fluorescence intensity of the dye layer sandwiched between two gold nanoparticle arrays. The interaction of the dye layer with the plasmonic system also causes a spectral shift in the emission wavelengths and a shortening of the fluorescence life times. Our work paves the way for large-scale, high throughput, and low-cost self-assembled functionalized plasmonic systems that can be used as efficient light sources

Molecular Velcro constructed from polymer loop brushes showing enhanced adhesion force

Science.gov (United States)

Zhou, Tian; Han, Biao; Han, Lin; Li, Christopher; Department of Materials Science; Engineering Team; School of Biomedical Engineering, Science; Health Systems Team

2015-03-01

Molecular Velcro is commonly seen in biological systems as the formation of strong physical entanglement at molecular scale could induce strong adhesion, which is crucial to many biological processes. To mimic this structure, we designed, and fabricated polymer loop brushes using polymer single crystals with desired surface functionality and controlled chain folding. Compared with reported loop brushes fabricated using triblock copolymers, the present loop bushes have precise loop sizes, loop grafting density, and well controlled tethering locations on the solid surface. Atomic force microscopy-based force spectroscopy measurements using a polymer chain coated probe reveal that the adhesion force are significantly enhanced on the loop brush surface as compared with its single-strand counterpart. This study directly shows the effect of polymer brush conformation on their properties, and suggests a promising strategy for advanced polymer surface design.

Neuro-Behcet's syndrome with contrast enhancement on brain computed tomography

International Nuclear Information System (INIS)

Yamada, Takeshi; Tobimatsu, Shozo; Itoyama, Yasuto; Goto, Ikuo; Kuroiwa, Yoshigoro

1986-01-01

Two cases of neuro-Behcet's syndrome (N-B) with contrast enhancement (enhancement) on brain computed tomography (CT) are reported. Case 1. A 34-year-old man, who had a history of recurrent aphthous stomatitis, developed a left inferior homonymous quadrantanopsia. CT scans showed a large lucent area with a ring-like enhancement (3 cm in diameter) lesion in the right parietooccipital region. When he developed a left hemiplegia, CT scans showed a irregular lucent area with heterogenous enhancement lesions in the right basal ganglia and midbrain. Case 2. A 38-year-old woman, who had a history of recurrent aphthous stomatitis and genital ulcer, developed mental confusion. CT scans showed a large lucent area with a homogenous marked round enhancement lesion in the left basal ganglia. When she developed generalized convulsion, CT scans showed a large lucent area with a heterogenous irregular enhancement lesion in the right occipital lobe. Enhancement lesions were observed in the area corresponded to their neurological symptoms during acute exacerbations and disappeared within three months. Our cases suggest that N-B with acute exacerbations could show transient enhancement on CT. (author)

A stochastic model of depolarization enhancement due to large energy spread in electron storage rings

International Nuclear Information System (INIS)

Buon, J.

1988-10-01

A new semiclassical and stochastic model of spin diffusion is used to obtain numerical predictions for depolarization enhancement due to beam energy spread. It confirms the results of previous models for the synchrotron sidebands of isolated spin resonances. A satisfactory agreement is obtained with the width of a synchrotron satellite observed at SPEAR. For HERA and LEP, at Z 0 energy, the depolarization enhancement is of the order of a few units and increases very rapidly with the energy spread. Large reduction of polarization degree is expected in these rings

Neighborhood diversity of large trees shows independent species patterns in a mixed dipterocarp forest in Sri Lanka.

Science.gov (United States)

Punchi-Manage, Ruwan; Wiegand, Thorsten; Wiegand, Kerstin; Getzin, Stephan; Huth, Andreas; Gunatilleke, C V Savitri; Gunatilleke, I A U Nimal

2015-07-01

Interactions among neighboring individuals influence plant performance and should create spatial patterns in local community structure. In order to assess the role of large trees in generating spatial patterns in local species richness, we used the individual species-area relationship (ISAR) to evaluate the species richness of trees of different size classes (and dead trees) in circular neighborhoods with varying radius around large trees of different focal species. To reveal signals of species interactions, we compared the ISAR function of the individuals of focal species with that of randomly selected nearby locations. We expected that large trees should strongly affect the community structure of smaller trees in their neighborhood, but that these effects should fade away with increasing size class. Unexpectedly, we found that only few focal species showed signals of species interactions with trees of the different size classes and that this was less likely for less abundant focal species. However, the few and relatively weak departures from independence were consistent with expectations of the effect of competition for space and the dispersal syndrome on spatial patterns. A noisy signal of competition for space found for large trees built up gradually with increasing life stage; it was not yet present for large saplings but detectable for intermediates. Additionally, focal species with animal-dispersed seeds showed higher species richness in their neighborhood than those with gravity- and gyration-dispersed seeds. Our analysis across the entire ontogeny from recruits to large trees supports the hypothesis that stochastic effects dilute deterministic species interactions in highly diverse communities. Stochastic dilution is a consequence of the stochastic geometry of biodiversity in species-rich communities where the identities of the nearest neighbors of a given plant are largely unpredictable. While the outcome of local species interactions is governed for each

The development of adaptive memory: Young children show enhanced retention of animacy-related information.

Science.gov (United States)

Aslan, Alp; John, Thomas

2016-12-01

Previous developmental work has indicated that animacy is a foundational ontogenetic category that is given priority already early in life. Here, we investigated whether such priority is also present in children's episodic memory, examining whether young children show enhanced retention of animacy-related information. Kindergartners and younger and older elementary school children were presented with fictitious (non)words (e.g., BULA, LAFE) paired with properties characteristic of humans (e.g., "likes music"), (nonhuman) animals (e.g., "builds nests"), and inanimate things (e.g., "has four edges") and were asked to rate the animacy status of each nonword. After a retention interval, a surprise recognition test for the nonwords was administered. We found enhanced recognition of nonwords paired with human and animal properties compared with (the same) nonwords paired with inanimate properties. The size of this animacy advantage was comparable across age groups, suggesting developmental invariance of the advantage over the age range examined (i.e., 4-11years). The results support a functional-evolutionary view on memory, suggesting that already young children's memory is "tuned" to process and retain animacy. Copyright © 2016 Elsevier Inc. All rights reserved.

Layer-controlled large area MoS{sub 2} layers grown on mica substrate for surface-enhanced Raman scattering

Energy Technology Data Exchange (ETDEWEB)

Xu, Y.Y.; Yang, C. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Jiang, S.Z. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); State Key Lab of Crystal Materials Shandong University, Jinan 250100 (China); Man, B.Y., E-mail: byman@sdnu.edu.cn [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Liu, M.; Chen, C.S.; Zhang, C.; Sun, Z.C.; Qiu, H.W. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Li, H.S. [Department of Radiation Oncology, Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan 250117 (China); Feng, D.J. [College of Information Science and Engineering, Shandong University, Jinan 250100 (China); Zhang, J.X. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China)

2015-12-01

Highlights: • Layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate at relatively low temperature. • The as-grown MoS{sub 2}/mica substrate was demonstrated to be suitable as a substrate for enhancing Raman signals without any modification and we even collected Raman signals of R6G as low as 10{sup −7} M. • Using the Raman peak of R6G at 1361 cm{sup −1} as a signature, Raman intensity showed an approximately linear increase with the increasing of the logarithm of R6G concentrations. - Abstract: Molybdenum disulfide has recently raised more and more interest due to its layer-related properties and potential applications in optoelectronics and electronics. Here, layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate. The obtained MoS{sub 2} film is three layers uniformly. Because of the small lattice mismatch between MoS{sub 2} and mica, the epitaxial MoS{sub 2} film is well grown on the substrate. The as-grown MoS{sub 2}/mica substrate is demonstrated to be suitable as a substrate for enhancing Raman signals of adsorbed molecules without any modification, which even can compare with graphene and will expand the application of MoS{sub 2} to microanalysis.

DNA abasic site-selective enhancement of sanguinarine fluorescence with a large emission shift.

Directory of Open Access Journals (Sweden)

Fei Wu

Full Text Available Small molecules that can specifically bind to a DNA abasic site (AP site have received much attention due to their importance in DNA lesion identification, drug discovery, and sensor design. Herein, the AP site binding behavior of sanguinarine (SG, a natural alkaloid, was investigated. In aqueous solution, SG has a short-wavelength alkanolamine emission band and a long-wavelength iminium emission band. At pH 8.3, SG experiences a fluorescence quenching for both bands upon binding to fully matched DNAs without the AP site, while the presence of the AP site induces a strong SG binding and the observed fluorescence enhancement for the iminium band are highly dependent on the nucleobases flanking the AP site, while the alkanolamine band is always quenched. The bases opposite the AP site also exert some modifications on the SG's emission behavior. It was found that the observed quenching for DNAs with Gs and Cs flanking the AP site is most likely caused by electron transfer between the AP site-bound excited-state SG and the nearby Gs. However, the flanking As and Ts that are not easily oxidized favor the enhanced emission. This AP site-selective enhancement of SG fluorescence accompanies a band conversion in the dominate emission from the alkanolamine to iminium band thus with a large emission shift of about 170 nm. Absorption spectra, steady-state and transient-state fluorescence, DNA melting, and electrolyte experiments confirm that the AP site binding of SG occurs and the stacking interaction with the nearby base pairs is likely to prevent the converted SG iminium form from contacting with water that is thus emissive when the AP site neighbors are bases other than guanines. We expect that this fluorophore would be developed as a promising AP site binder having a large emission shift.

Properties and uses of storage for enhancing the grid penetration of very large photovoltaic systems

International Nuclear Information System (INIS)

Solomon, A.A.; Faiman, D.; Meron, G.

2010-01-01

In this third paper, which studies the hourly generation data for the year 2006 from the Israel Electric Corporation, with a view to incorporating very large photovoltaic (PV) power plants, we address the question: What properties should storage have in order to enhance the grid penetration of large PV systems in an efficient and substantial manner? We first impose the constraint that no PV energy losses are permitted other than those due to storage inefficiency. This constraint leads to powerful linkages between the energy capacity and power capacity of storage, and PV system size, and their combined effect on grid penetration. Various strategies are then examined for enhancing grid penetration, based upon this newfound knowledge. Specific strategies examined include PV energy dumping and baseload rescheduling both on a seasonal basis and shorter time periods. We found, inter alia, that at high grid flexibilities (in the range ff=0.8-1), PV grid penetration levels could be possible in the range 60-90% of annual requirements. Moreover, with appropriately designed storage and accurate forecasting, a future grid could be operated at ff=1.

19 CFR 113.75 - Bond conditions for deferral of duty on large yachts imported for sale at United States boat shows.

Science.gov (United States)

2010-04-01

... yachts imported for sale at United States boat shows. 113.75 Section 113.75 Customs Duties U.S. CUSTOMS... Customs Bond Conditions § 113.75 Bond conditions for deferral of duty on large yachts imported for sale at....C. 1484b for a dutiable large yacht imported for sale at a United States boat show must conform to...

Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

Energy Technology Data Exchange (ETDEWEB)

Praveen, D. [Department of Physics, Amrita Viswha Vidyapeetham, Bangalore, India, E-mail: d-praveen@blr.amrita.edu (India); Damle, Ramakrishna [Department of Physics, Bangalore University, Bangalore, India. E-mail: ramkrishnadamle@bub.ernet.in (India)

2016-05-23

Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO{sub 4}){sub 2}, NH{sub 4}I etc., have already been tried in the past with some success. Also various nanoparticles like Al{sub 2}O{sub 3}, TiO{sub 2} etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

International Nuclear Information System (INIS)

Praveen, D.; Damle, Ramakrishna

2016-01-01

Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO_4)_2, NH_4I etc., have already been tried in the past with some success. Also various nanoparticles like Al_2O_3, TiO_2 etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

Steam-exploded biomass saccharification is predominately affected by lignocellulose porosity and largely enhanced by Tween-80 in Miscanthus.

Science.gov (United States)

Sun, Dan; Alam, Aftab; Tu, Yuanyuan; Zhou, Shiguang; Wang, Yanting; Xia, Tao; Huang, Jiangfeng; Li, Ying; Zahoor; Wei, Xiaoyang; Hao, Bo; Peng, Liangcai

2017-09-01

In this study, total ten Miscanthus accessions exhibited diverse cell wall compositions, leading to largely varied hexoses yields at 17%-40% (% cellulose) released from direct enzymatic hydrolysis of steam-exploded (SE) residues. Further supplied with 2% Tween-80 into the enzymatic digestion, the Mis7 accession showed the higher hexose yield by 14.8-fold than that of raw material, whereas the Mis10 had the highest hexoses yield at 77% among ten Miscanthus accessions. Significantly, this study identified four wall polymer features that negatively affect biomass saccharification as pbiomass enzymatic digestion. Hence, this study provides the potential strategy to enhance biomass saccharification using optimal biomass process technology and related genetic breeding in Miscanthus and beyond. Copyright © 2017 Elsevier Ltd. All rights reserved.

19 CFR Appendix C to Part 113 - Bond for Deferral of Duty on Large Yachts Imported for Sale at United States Boat Shows

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Bond for Deferral of Duty on Large Yachts Imported... Appendix C to Part 113—Bond for Deferral of Duty on Large Yachts Imported for Sale at United States Boat Shows Bond for Deferral of Duty on Large Yachts Imported for Sale at United States Boat Shows ____, as...

Perfusion magnetic resonance imaging and magnetic resonance spectroscopy of cerebral gliomas showing imperceptible contrast enhancement on conventional magnetic resonance imaging

International Nuclear Information System (INIS)

Batra, A.; Tripathi, R.P.; Singh, A.K.

2004-01-01

The purpose of the present paper was to evaluate the utility of perfusion MRI in cerebral gliomas showing imperceptible contrast enhancement on conventional MRI, and to evaluate the relationships of perfusion MRI and magnetic resonance (MR) spectroscopic results in these tumours. Twenty-two patients with histopathologically proven cerebral gliomas and showing insignificant contrast enhancement on conventional MR were included in the present study. All patients underwent perfusion MRI and MR spectroscopy on a 1.5-T MR system. Significant differences of the relative cerebral blood volume (rCBV) values and the choline : creatine ratios were noted between low-grade and anaplastic gliomas (P < 0.01). Good correlation was found between the rCBV values and the choline : creatine values (y = 0. 532x + 1.5643; r = 0.67). Perfusion MRI can be a useful tool in assessing the histopathological grade of non-contrast-enhancing cerebral gliomas. Along with MR spectroscopic imaging it can serve as an important technique for preoperative characterization of such gliomas, so that accurate targeting by stereotactic biopsies is possible. Copyright (2004) Blackwell Science Pty Ltd

Development of solution monitoring software for enhanced safeguards at a large scale reprocessing facility

Energy Technology Data Exchange (ETDEWEB)

Van Handenhove, Carl; Breban, Domnica; Creusot, Christophe [International Atomic Energy Agency, Vienna (Austria); Dransart, Pascal; Dechamp, Luc [Joint Research Centre, European Commission, Ispra, Varese, (Italy); Jarde, Eric [Euriware, Equeurdreville (France)

2011-12-15

The implementation of an effective and efficient IAEA safeguards approach at large scale reprocessing facilities with large throughput and continuous flow of nuclear material requires the introduction of enhanced safeguards measures to provide added assurance about the absence of diversion of nuclear material and confirmation that the facility is operated as declared. One of the enhanced safeguards measures, a Solution Monitoring and Measurement System (SMMS), comprising data collection instruments, data transmission equipment and an advanced Solution Monitoring Software (SMS), is being implemented at a large scale reprocessing plant in Japan. SMS is designed as a tool to enable automatic calculations of volumes, densities and flow-rates in selected process vessels, including most of the vessels of the main nuclear material stream. This software also includes automatic features to support the inspectorate in verifying inventories and inventory changes. The software also enables one to analyze the flows of nuclear material within the process and of specified 'cycles' of operation, and, in order to provide assurance that the facility is being operated as declared to compare these with those expected (reference signatures). The configuration and parameterization work (especially the analytical and comparative work) for the implementation and configuration of the SMS has been carried out jointly between the IAEA, Euriware-France (the software developer) and the Joint Research Centre (JRC)-Ispra. This paper describes the main features of the SMS, including the principles underlying the automatic analysis functionalities. It then focuses on the collaborative work performed by the JRC-Ispra, Euriware and the IAEA for the parameterization of the software (vessels and cycles of operation), including the current status and the future challenges.

MILDOS-AREA: An enhanced version of MILDOS for large-area sources

International Nuclear Information System (INIS)

Yuan, Y.C.; Wang, J.H.C.; Zielen, A.

1989-06-01

The MILDOS-AREA computer code is a modified version of the MILDOS code, which estimates the radiological impacts of airborne emissions from uranium mining and milling facilities or any other large-area source involving emissions of radioisotopes of the uranium-238 series. MILDOS-AREA is designed for execution on personal computers. The modifications incorporated in the MILDOS-AREA code provide enhanced capabilities for calculating doses from large-area sources and update dosimetry calculations. The major revision from the original MILDOS code is the treatment of atmospheric dispersion from area sources: MILDOS-AREA substitutes a finite element integration approach for the virtual-point method (the algorithm used in the original MILDOS code) when specified by the user. Other revisions include the option of using Martin-Tickvart dispersion coefficients in place of Briggs coefficients for a given source, consideration of plume reflection, and updated internal dosimetry calculations based on the most recent recommendations of the International Commission on Radiation Protection and the age-specific dose calculation methodology developed by Oak Ridge National Laboratory. This report also discusses changes in computer code structure incorporated into MILDOS-AREA, summarizes data input requirements, and provides instructions for installing and using the program on personal computers. 15 refs., 9 figs., 26 tabs

Emergent Low-Symmetry Phases and Large Property Enhancements in Ferroelectric KNbO ₃ Bulk Crystals

Energy Technology Data Exchange (ETDEWEB)

Lummen, Tom T. A. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Leung, J. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Kumar, Amit [School of Mathematics and Physics, Queen' s University Belfast, University Road, Belfast BT71NN Northern Ireland UK; Wu, X. [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; Ren, Y. [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; VanLeeuwen, Brian K. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Haislmaier, Ryan C. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Holt, Martin [Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL 60439 USA; Lai, Keji [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Gopalan, Venkatraman [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA

2017-06-19

The design of new or enhanced functionality in materials is traditionally viewed as requiring the discovery of new chemical compositions through synthesis. Large property enhancements may however also be hidden within already well-known materials, when their structural symmetry is deviated from equilibrium through a small local strain or field. Here, the discovery of enhanced material properties associated with a new metastable phase of monoclinic symmetry within bulk KNbO3 is reported. This phase is found to coexist with the nominal orthorhombic phase at room temperature, and is both induced by and stabilized with local strains generated by a network of ferroelectric domain walls. While the local microstructural shear strain involved is only approximate to 0.017%, the concurrent symmetry reduction results in an optical second harmonic generation response that is over 550% higher at room temperature. Moreover, the meandering walls of the low-symmetry domains also exhibit enhanced electrical conductivity on the order of 1 S m(-1). This discovery reveals a potential new route to local engineering of significant property enhancements and conductivity through symmetry lowering in ferroelectric crystals.

Bi-functional TiO2 cemented Ag grid under layer for enhancing the photovoltaic performance of a large-area dye-sensitized solar cell

International Nuclear Information System (INIS)

Lan Zhang; Wu Jihuai; Lin Jianming; Huang, Miaoliang

2012-01-01

Graphical abstract: Enhanced photovoltaic performance of large-area DSSC with conductive grids in the photo and counter electrodes. Highlights: ► TiO 2 protected Ag grids is made for using as electrode in large-area DSSC. ► The electrode has high conductivity and low internal resistance. ► TiO 2 protected Ag grids electrode avoids iodine corrosion in electrolyte. ► The TiO 2 layer also play a blocking layer role. ► Above factors enhance the photovoltaic performance of large-area DSSC. - Abstract: A bi-functional TiO 2 cemented Ag grid under layer for enhanced the photovoltaic performance of a large-area dye-sensitized solar cell (DSSC) is prepared with a simple way. The conductive printing paste contains micro-sized Ag powders and nano-sized TiO 2 cementing agent. The conductive printing paste can be well cemented on the FTO glass and form high conductive grids with Ag powders sintered together by the nano-sized TiO 2 particles. The formed conductive grid is protected with a TiO 2 thin layer and TiO 2 sol treatment to avoid the iodine corrosion. The addition of the TiO 2 cemented conductive grid can decrease the internal resistance of the large-area dye-sensitized solar cell when it is prepared in the photo and counter electrodes. Furthermore, the protecting TiO 2 thin layer and the TiO 2 sol treatment can be done on the whole area of the large-area photo electrode to both play as the blocking under layer at the same time, which can also enhance the photovoltaic performance of the large-area dye-sensitized solar cell.

Precursory enhancement of EIA in the morning sector: Contribution from mid-latitude large earthquakes in the north-east Asian region

Science.gov (United States)

Ryu, Kwangsun; Oyama, Koh-Ichiro; Bankov, Ludmil; Chen, Chia-Hung; Devi, Minakshi; Liu, Huixin; Liu, Jann-Yenq

2016-01-01

To investigate whether the link between seismic activity and EIA (equatorial ionization anomaly) enhancement is valid for mid-latitude seismic activity, DEMETER observations around seven large earthquakes in the north-east Asian region were fully analyzed (M ⩾ 6.8). In addition, statistical analysis was performed for 35 large earthquakes (M ⩾ 6.0) that occurred during the DEMETER observation period. The results suggest that mid-latitude earthquakes do contribute to EIA enhancement, represented as normalized equatorial Ne , and that ionospheric change precedes seismic events, as has been reported in previous studies. According to statistical studies, the normalized equatorial density enhancement is sensitive and proportional to both the magnitude and the hypocenter depth of an earthquake. The mechanisms that can explain the contribution of mid-latitude seismic activity to EIA variation are briefly discussed based on current explanations of the geochemical and ionospheric processes involved in lithosphere-ionosphere interaction.

Large-scale and green synthesis of octahedral flower-like cupric oxide nanocrystals with enhanced photochemical properties

Science.gov (United States)

Li, Shi-Kuo; Pan, Yu-Yi; Wu, Mi; Huang, Fang-Zhi; Li, Chuan-Hao; Shen, Yu-Hua

2014-10-01

In this work, a large-scale and green method is reported for the facile synthesis of octahedral flower-like CuO nanocrystals via a coordination-deposition route by using Fehling regents. Not any harmful organic chemicals were used during the reaction period. The obtained hierarchical nanostructure can be rationally tailored by varying the concentration of tartrate ions and reaction time. The typical flower-like CuO nanocrystals in the range of 200-250 nm are consisted of numerous small crystalline whiskers, which present a porous surface with a specific surface area of 32.12 m2/g and a narrow band gap of 1.5 eV. Importantly, the flower-like CuO nanocrystals show an enhanced photocatalytic activity toward decomposing Rhodamine B (RhB) molecules. The degradation rate is about 87.9% in 40 min under visible light irradiation, which is about 2.5 times for the commercial CuO powers (35.2%). Moreover, the uniform flower-like monolayered CuO film exhibits an excellent photoelectrochemical (PEC) performance with a maximum photocurrent density of 58.8 μA/cm2, which is nearly five times higher than the commercial CuO film. This novel synthesis approach provides a large-scale and green protocol for synthesizing hierarchical metal oxide nanocrystals that are useful for photocatalysis, PEC water splitting and photovoltaic device.

The price effects of enhancing services sector competition in a large open economy

NARCIS (Netherlands)

P.A.D. Cavelaars

2003-01-01

textabstractThis paper studies the price e?ects of shocks to the degree of competition. It is motivated by initiatives to enhance competition in services in the European Union. The paper shows that a higher degree of competition in the nontradable goods sector may have adverse implications for

Theoretical evaluations of magnetic nanoparticle-enhanced heating on tumor embedded with large blood vessels during hyperthermia

International Nuclear Information System (INIS)

Wang, Q.; Deng, Z. S.; Liu, J.

2012-01-01

The large blood vessels surrounding the tumor would significantly result in heat sink, and thus seriously limit the thermal ablative area during tumor hyperthermia. Magnetic nanoparticle (MNP) was recently identified as an important heating enhancer to improve the treatment efficiency. It will not only help to absorb more energy under the irradiation of external magnetic field, but also can block the blood flow and subsequently weaken the heat sink effect of large vessels. In this study, these two critical factors, reserved to be undisclosed before in theory, were comprehensively investigated through three-dimensional numerical simulation. The results suggested that concerning the contribution to temperature increase in the tissues surrounding large vessel, the factor of blood flow blocking is more effective than that of energy absorption. Therefore, selective loading of MNPs to the target sites is expected to serve as a promising method to perform successful hyperthermia treatment for tumor tissues embedded with large blood vessels.

Theoretical evaluations of magnetic nanoparticle-enhanced heating on tumor embedded with large blood vessels during hyperthermia

Energy Technology Data Exchange (ETDEWEB)

Wang, Q. [Tsinghua University, Department of Biomedical Engineering, School of Medicine (China); Deng, Z. S. [Chinese Academy of Sciences, Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry (China); Liu, J., E-mail: jliubme@tsinghua.edu.cn [Tsinghua University, Department of Biomedical Engineering, School of Medicine (China)

2012-07-15

The large blood vessels surrounding the tumor would significantly result in heat sink, and thus seriously limit the thermal ablative area during tumor hyperthermia. Magnetic nanoparticle (MNP) was recently identified as an important heating enhancer to improve the treatment efficiency. It will not only help to absorb more energy under the irradiation of external magnetic field, but also can block the blood flow and subsequently weaken the heat sink effect of large vessels. In this study, these two critical factors, reserved to be undisclosed before in theory, were comprehensively investigated through three-dimensional numerical simulation. The results suggested that concerning the contribution to temperature increase in the tissues surrounding large vessel, the factor of blood flow blocking is more effective than that of energy absorption. Therefore, selective loading of MNPs to the target sites is expected to serve as a promising method to perform successful hyperthermia treatment for tumor tissues embedded with large blood vessels.

Deal or No Deal? Decision Making under Risk in a Large-Stake TV Game Show and Related Experiments

NARCIS (Netherlands)

M.J. van den Assem (Martijn)

2008-01-01

textabstractThe central theme of this dissertation is the analysis of risky choice. The first two chapters analyze the choice behavior of contestants in a TV game show named “Deal or No Deal” (DOND). DOND provides a unique opportunity to study risk behavior, because it is characterized by very large

The Sommerfeld enhancement for dark matter with an excited state

International Nuclear Information System (INIS)

Slatyer, Tracy R.

2010-01-01

We present an analysis of the Sommerfeld enhancement to dark matter annihilation in the presence of an excited state, where the interaction inducing the enhancement is purely off-diagonal, such as in models of exciting or inelastic dark matter. We derive a simple and accurate semi-analytic approximation for the s-wave enhancement, which is valid provided the mass splitting between the ground and excited states is not too large, and discuss the cutoff of the enhancement for large mass splittings. We reproduce previously derived results in the appropriate limits, and demonstrate excellent agreement with numerical calculations of the enhancement. We show that the presence of an excited state leads to generically larger values of the Sommerfeld enhancement, larger resonances, and shifting of the resonances to lower mediator masses. Furthermore, in the presence of a mass splitting the enhancement is no longer a monotonic function of velocity: the enhancement where the kinetic energy is close to that required to excite the higher state can be up to twice as large as the enhancement at zero velocity

Large enhancement of Faraday rotation by localized surface plasmon resonance in Au nanoparticles embedded in Bi:YIG film

International Nuclear Information System (INIS)

Uchida, H.; Masuda, Y.; Fujikawa, R.; Baryshev, A.V.; Inoue, M.

2009-01-01

A large enhancement of the Faraday rotation, which is associated with localized surface plasmon resonance (LSPR), was obtained in a sample with Au nanoparticles embedded in a Bi-substituted yttrium iron garnet (Bi:YIG) film. On a quartz substrate, Au nanoparticles were formed by heating an Au thin film, and a Bi:YIG film was then deposited on them. A sample containing the Au nanoparticles produced by 1000 deg. C heating showed a resonant attenuation with narrower bandwidth in the transmission spectrum than nanoparticles of other samples formed by low-temperature heating. The sharp resonant Faraday rotation angle was 4.4 times larger than the estimated intrinsic Bi:YIG film at the LSPR wavelength; the angular difference was 0.14 deg. A discrepancy in the bandwidth between the transmission attenuation and the resonant Faraday rotation is discussed

Self-Assembled Complexes of Horseradish Peroxidase with Magnetic Nanoparticles Showing Enhanced Peroxidase Activity

KAUST Repository

Corgié, Stéphane C.

2012-02-15

Bio-nanocatalysts (BNCs) consisting of horseradish peroxidase (HRP) self-assembled with magnetic nanoparticles (MNPs) enhance enzymatic activity due to the faster turnover and lower inhibition of the enzyme. The size and magnetization of the MNPs affect the formation of the BNCs, and ultimately control the activity of the bound enzymes. Smaller MNPs form small clusters with a low affinity for the HRP. While the turnover for the bound fraction is drastically increased, there is no difference in the H 2O 2 inhibitory concentration. Larger MNPs with a higher magnetization aggregate in larger clusters and have a higher affinity for the enzyme and a lower substrate inhibition. All of the BNCs are more active than the free enzyme or the MNPs (BNCs > HRP ≤laquo; MNPs). Since the BNCs show surprising resilience in various reaction conditions, they may pave the way towards new hybrid biocatalysts with increased activities and unique catalytic properties for magnetosensitive enzymatic reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

Science.gov (United States)

Huang, Yu; Wei, Xiaoyang; Zhou, Shiguang; Liu, Mingyong; Tu, Yuanyuan; Li, Ao; Chen, Peng; Wang, Yanting; Zhang, Xuewen; Tai, Hongzhong; Peng, Liangcai; Xia, Tao

2015-04-01

In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond. Copyright © 2015 Elsevier Ltd. All rights reserved.

ROSAT view of the ISM in the Large Magellanic Cloud

Science.gov (United States)

Chu, You-Hua

1996-01-01

Rosat observations of the Large Magellanic Cloud (LMC) show a large scale unbounded diffuse X-ray emission, as well as an enhanced emission within large shell structures. These observations allow the distribution of hot ionized medium in the LMC to be examined. Moreover, the hot interior of supernova shells and superbubbles, supernova remnants and the multi-phase structure of the interstellar medium (ISM) can be investigated.

Endothelial Protein C–Targeting Liposomes Show Enhanced Uptake and Improved Therapeutic Efficacy in Human Retinal Endothelial Cells

DEFF Research Database (Denmark)

Arta, Anthoula; Eriksen, Anne Z.; Melander, Fredrik

2018-01-01

PURPOSE. To determine whether human retinal endothelial cells (HRECs) express the endothelial cell protein C receptor (EPCR) and to realize its potential as a targeting moiety by developing novel single and dual corticosteroid–loaded functionalized liposomes that exhibit both enhanced uptake by H...... of cell tube formations in contrast to nontargeting liposomes. CONCLUSIONS. We show that HRECs express EPCR and this receptor could be a promising nanomedicine target in ocular diseases where the endothelial barrier of the retina is compromised....

An efficient top-down approach for the fabrication of large-aspect-ratio g-C3N4 nanosheets with enhanced photocatalytic activities.

Science.gov (United States)

Tong, Jincheng; Zhang, Li; Li, Fei; Li, Mingming; Cao, Shaokui

2015-09-28

Graphitic carbon nitride (g-C3N4) nanosheets with large aspect ratios were fabricated from bulk g-C3N4 through an efficient top-down approach of moderate disintegration-exfoliation using diluted H2SO4 as an "efficient knife". By prior disintegration in a diluted H2SO4 solution, the exfoliation of bulk g-C3N4 was effectively accelerated. The as-prepared g-C3N4 nanosheets possess a two-dimensional (2D) thin-layer structure with seven-atom thickness, a large lateral size of about 1 μm, and a high specific surface area of 80 m(2) g(-1). Compared with the bulk precursor, the g-C3N4 nanosheets showed much higher efficiency of photogenerated charge transfer and separation, and consequently exhibited enhanced photocatalytic activity toward hydrogen evolution and pollutant decomposition under both full-sunlight and visible-light irradiation.

A case of falx meningiomas showing an unusual extension on CT

International Nuclear Information System (INIS)

Tsuha, Mitsuru; Fudaba, Hiroyoshi; Orita, Tetsuji; Wakuta, Yukio; Aoki, Hideo

1986-01-01

It is well known that homogeneous high-density areas with well-defined borders and marked contrast enhancements on CT scans are characteristic features of meningiomas. However, there are a few cases of meningiomas which are more difficult to diagnose because of their unusual CT findings. We have, for example, recently experienced a case of falx meningioma with a small attachment to the flax and a large exophytic component in the brain parenchyma. This 53-year-old female had complained of dull headaches for several years. She had then suffered speech disturbance in June, 1983, followed by a weakness of her right arm. She was referred to our clinic on Oct. 31, 1983. The neurological findings on admission were dyscalculia, mild motor dysphasia, and right hemiparesis to a minor degree. CT revealed a left frontal iso- and high-density mass lesion and also central, partly visible, low-density areas. A postinfusion study showed a moderate contrast enhancement. Also noted were a partial attachment of these tumors to the falx and a more prominent contrast enhancement of these areas than those of other tumor sites. A left internal carotid angiogram revealed a frontal tumor stain, fed by the left ACA and MCAs; early venous drainage was also seen. Moreover, left external carotid angiography showed a small tumor stain adjacent to the falx. Left frontoparietal craniotomy, on Nov. 14, 1983, revealed a soft, well-defined tumor, partly attached to the tumor. Histology indicated a meningioma with partial anisocytosis and mitoses of tumor cells; this was consequently diagnosed as a malignant meningioma. Intracranial meningiomas with a small attachment to the falx and large areas of exophytic components are rare CT findings. In addition to the CT findings mentioned above, the heterogeneity of the absorption coefficients of meningiomas on CT and differential diagnosis were discussed. (author)

Psychopaths show enhanced amygdala activation during fear conditioning

Directory of Open Access Journals (Sweden)

Douglas eSchultz

2016-03-01

Full Text Available Psychopathy is a personality disorder characterized by emotional deficits and a failure to inhibit impulsive behavior and is often subdivided into primary and secondary psychopathic subtypes. The maladaptive behavior related to primary psychopathy is thought to reflect constitutional fearlessness, while the problematic behavior related to secondary psychopathy is motivated by other factors. The fearlessness observed in psychopathy has often been interpreted as reflecting a fundamental deficit in amygdala function, and previous studies have provided support for a low-fear model of psychopathy. However, many of these studies fail to use appropriate screening procedures, use liberal inclusion criteria, or have used unconventional approaches to assay amygdala function. We measured brain activity with BOLD imaging in primary and secondary psychopaths and non-psychopathic control subjects during Pavlovian fear conditioning. In contrast to the low-fear model, we observed normal fear expression in primary psychopaths. Psychopaths also displayed greater differential BOLD activity in the amygdala relative to matched controls. Inverse patterns of activity were observed in the anterior cingulate cortex (ACC for primary versus secondary psychopaths. Primary psychopaths exhibited a pattern of activity in the dorsal and ventral ACC consistent with enhanced fear expression, while secondary psychopaths exhibited a pattern of activity in these regions consistent with fear inhibition. These results contradict the low-fear model of psychopathy and suggest that the low fear observed for psychopaths in previous studies may be specific to secondary psychopaths.

Power flow control and damping enhancement of a large wind farm using a superconducting magnetic energy storage unit

DEFF Research Database (Denmark)

Chen, S. S.; Wang, L.; Lee, W. J.

2009-01-01

A novel scheme using a superconducting magnetic energy storage (SMES) unit to perform both power flow control and damping enhancement of a large wind farm (WF) feeding to a utility grid is presented. The studied WF consisting of forty 2 MW wind induction generators (IGs) is simulated...

Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

Energy Technology Data Exchange (ETDEWEB)

Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Wang, Qingguo, E-mail: wqgyyy@126.com [College of Food Science and Engineering, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Xu, Jing, E-mail: jiaxu@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China)

2016-11-15

Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm{sup −1}) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

International Nuclear Information System (INIS)

Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

2016-01-01

Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm −1 ) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

Transformation of Lettuce with rol ABC Genes: Extracts Show Enhanced Antioxidant, Analgesic, Anti-Inflammatory, Antidepressant, and Anticoagulant Activities in Rats.

Science.gov (United States)

Ismail, Hammad; Dilshad, Erum; Waheed, Mohammad Tahir; Mirza, Bushra

2017-03-01

Lettuce is an edible crop that is well known for dietary and antioxidant benefits. The present study was conducted to investigate the effects of rol ABC genes on antioxidant and medicinal potential of lettuce by Agrobacterium-mediated transformation. Transgene integration and expression was confirmed through PCR and real-time RT-PCR, respectively. The transformed plants showed 91-102 % increase in total phenolic contents and 53-65 % increase in total flavonoid contents compared to untransformed plants. Total antioxidant capacity and total reducing power increased up to 112 and 133 % in transformed plants, respectively. Results of DPPH assay showed maximum 51 % increase, and lipid peroxidation assay exhibited 20 % increase in antioxidant activity of transformed plants compared to controls. Different in vivo assays were carried out in rats. The transgenic plants showed up to 80 % inhibition in both hot plate analgesic assay and carrageenan-induced hind paw edema test, while untransformed plants showed only 45 % inhibition. Antidepressant and anticoagulant potential of transformed plants was also significantly enhanced compared to untransformed plants. Taken together, the present work highlights the use of rol genes to enhance the secondary metabolite production in lettuce and improve its analgesic, anti-inflammatory, antidepressant, and anticoagulatory properties.

Resonant Scanning with Large Field of View Reduces Photobleaching and Enhances Fluorescence Yield in STED Microscopy.

Science.gov (United States)

Wu, Yong; Wu, Xundong; Lu, Rong; Zhang, Jin; Toro, Ligia; Stefani, Enrico

2015-10-01

Photobleaching is a major limitation of superresolution Stimulated Depletion Emission (STED) microscopy. Fast scanning has long been considered an effective means to reduce photobleaching in fluorescence microscopy, but a careful quantitative study of this issue is missing. In this paper, we show that the photobleaching rate in STED microscopy can be slowed down and the fluorescence yield be enhanced by scanning with high speed, enabled by using large field of view in a custom-built resonant-scanning STED microscope. The effect of scanning speed on photobleaching and fluorescence yield is more remarkable at higher levels of depletion laser irradiance, and virtually disappears in conventional confocal microscopy. With ≥6 GW∙cm(-2) depletion irradiance, we were able to extend the fluorophore survival time of Atto 647N and Abberior STAR 635P by ~80% with 8-fold wider field of view. We confirm that STED Photobleaching is primarily caused by the depletion light acting upon the excited fluorophores. Experimental data agree with a theoretical model. Our results encourage further increasing the linear scanning speed for photobleaching reduction in STED microscopy.

Using interpreted large scale aerial photo data to enhance satellite-based mapping and explore forest land definitions

Science.gov (United States)

Tracey S. Frescino; Gretchen G. Moisen

2009-01-01

The Interior-West, Forest Inventory and Analysis (FIA), Nevada Photo-Based Inventory Pilot (NPIP), launched in 2004, involved acquisition, processing, and interpretation of large scale aerial photographs on a subset of FIA plots (both forest and nonforest) throughout the state of Nevada. Two objectives of the pilot were to use the interpreted photo data to enhance...

Large-scale and green synthesis of octahedral flower-like cupric oxide nanocrystals with enhanced photochemical properties

International Nuclear Information System (INIS)

Li, Shi-Kuo; Pan, Yu-Yi; Wu, Mi; Huang, Fang-Zhi; Li, Chuan-Hao; Shen, Yu-Hua

2014-01-01

Graphical abstract: - Highlights: • A green method is reported for large-scale synthesis of CuO nanocrystals via a coordination-deposition technique. • Flower-like nanostructure can be rationally tailored by adjusting reaction parameters. • Flower-like nanostructure can be obtained in a wide reaction solution volume range. • Uniform flower-like nanocrystal film assembled by oil–water interfacial self-assembly method exhibits excellent PEC performance. - Abstract: In this work, a large-scale and green method is reported for the facile synthesis of octahedral flower-like CuO nanocrystals via a coordination-deposition route by using Fehling regents. Not any harmful organic chemicals were used during the reaction period. The obtained hierarchical nanostructure can be rationally tailored by varying the concentration of tartrate ions and reaction time. The typical flower-like CuO nanocrystals in the range of 200–250 nm are consisted of numerous small crystalline whiskers, which present a porous surface with a specific surface area of 32.12 m 2 /g and a narrow band gap of 1.5 eV. Importantly, the flower-like CuO nanocrystals show an enhanced photocatalytic activity toward decomposing Rhodamine B (RhB) molecules. The degradation rate is about 87.9% in 40 min under visible light irradiation, which is about 2.5 times for the commercial CuO powers (35.2%). Moreover, the uniform flower-like monolayered CuO film exhibits an excellent photoelectrochemical (PEC) performance with a maximum photocurrent density of 58.8 μA/cm 2 , which is nearly five times higher than the commercial CuO film. This novel synthesis approach provides a large-scale and green protocol for synthesizing hierarchical metal oxide nanocrystals that are useful for photocatalysis, PEC water splitting and photovoltaic device

Large-scale and green synthesis of octahedral flower-like cupric oxide nanocrystals with enhanced photochemical properties

Energy Technology Data Exchange (ETDEWEB)

Li, Shi-Kuo; Pan, Yu-Yi; Wu, Mi; Huang, Fang-Zhi; Li, Chuan-Hao, E-mail: lichuanhao1983@163.com; Shen, Yu-Hua, E-mail: s_yuhua@163.com

2014-10-01

Graphical abstract: - Highlights: • A green method is reported for large-scale synthesis of CuO nanocrystals via a coordination-deposition technique. • Flower-like nanostructure can be rationally tailored by adjusting reaction parameters. • Flower-like nanostructure can be obtained in a wide reaction solution volume range. • Uniform flower-like nanocrystal film assembled by oil–water interfacial self-assembly method exhibits excellent PEC performance. - Abstract: In this work, a large-scale and green method is reported for the facile synthesis of octahedral flower-like CuO nanocrystals via a coordination-deposition route by using Fehling regents. Not any harmful organic chemicals were used during the reaction period. The obtained hierarchical nanostructure can be rationally tailored by varying the concentration of tartrate ions and reaction time. The typical flower-like CuO nanocrystals in the range of 200–250 nm are consisted of numerous small crystalline whiskers, which present a porous surface with a specific surface area of 32.12 m{sup 2}/g and a narrow band gap of 1.5 eV. Importantly, the flower-like CuO nanocrystals show an enhanced photocatalytic activity toward decomposing Rhodamine B (RhB) molecules. The degradation rate is about 87.9% in 40 min under visible light irradiation, which is about 2.5 times for the commercial CuO powers (35.2%). Moreover, the uniform flower-like monolayered CuO film exhibits an excellent photoelectrochemical (PEC) performance with a maximum photocurrent density of 58.8 μA/cm{sup 2}, which is nearly five times higher than the commercial CuO film. This novel synthesis approach provides a large-scale and green protocol for synthesizing hierarchical metal oxide nanocrystals that are useful for photocatalysis, PEC water splitting and photovoltaic device.

Sea-anemone toxin ATX-II elicits A-fiber-dependent pain and enhances resurgent and persistent sodium currents in large sensory neurons

Directory of Open Access Journals (Sweden)

Klinger Alexandra B

2012-09-01

Full Text Available Abstract Background Gain-of-function mutations of the nociceptive voltage-gated sodium channel Nav1.7 lead to inherited pain syndromes, such as paroxysmal extreme pain disorder (PEPD. One characteristic of these mutations is slowed fast-inactivation kinetics, which may give rise to resurgent sodium currents. It is long known that toxins from Anemonia sulcata, such as ATX-II, slow fast inactivation and skin contact for example during diving leads to various symptoms such as pain and itch. Here, we investigated if ATX-II induces resurgent currents in sensory neurons of the dorsal root ganglion (DRGs and how this may translate into human sensations. Results In large A-fiber related DRGs ATX-II (5 nM enhances persistent and resurgent sodium currents, but failed to do so in small C-fiber linked DRGs when investigated using the whole-cell patch-clamp technique. Resurgent currents are thought to depend on the presence of the sodium channel β4-subunit. Using RT-qPCR experiments, we show that small DRGs express significantly less β4 mRNA than large sensory neurons. With the β4-C-terminus peptide in the pipette solution, it was possible to evoke resurgent currents in small DRGs and in Nav1.7 or Nav1.6 expressing HEK293/N1E115 cells, which were enhanced by the presence of extracellular ATX-II. When injected into the skin of healthy volunteers, ATX-II induces painful and itch-like sensations which were abolished by mechanical nerve block. Increase in superficial blood flow of the skin, measured by Laser doppler imaging is limited to the injection site, so no axon reflex erythema as a correlate for C-fiber activation was detected. Conclusion ATX-II enhances persistent and resurgent sodium currents in large diameter DRGs, whereas small DRGs depend on the addition of β4-peptide to the pipette recording solution for ATX-II to affect resurgent currents. Mechanical A-fiber blockade abolishes all ATX-II effects in human skin (e.g. painful and itch

Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing

Science.gov (United States)

Xiao, Bo; Pradhan, Sangram K.; Santiago, Kevin C.; Rutherford, Gugu N.; Pradhan, Aswini K.

2016-04-01

We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing.

Magnetic resonance imaging of large chromophobe renal cell carcinomas

International Nuclear Information System (INIS)

Sasaguri, Kohei; Irie, Hiroyuki; Kamochi, Noriyuki; Nakazono, Takahiko; Yamaguchi, Ken; Uozumi, Jiro; Kudo, Sho

2010-01-01

The objective of this study was to clarify the magnetic resonance imaging (MRI) findings of large chromophobe renal cell carcinomas. Five patients diagnosed pathologically with chromophobe renal cell carcinoma are included. MRI findings were retrospectively evaluated for the tumor contour, uniformity and hypointensity of the rim of the tumor on T2-weighted images, ''micro-scopic fat'', enhancement degree and pattern on dynamic study, and necrosis in the tumor, among other findings. The tumor size ranged from 4.8 to 13.7 cm (mean 7.9 cm). The tumor contour was well defined in four patients. All but one tumor showed a hypointensity rim, and all tumors had a heterogeneous appearance on T2-weighted images. ''Microscopic fat'' was detected in one case. All tumors demonstrated low enhancement compared to that of the renal cortex. All tumors showed heterogeneous enhancement on postcontrast images. Necrosis was seen in four. Hemorrhage and renal vein thrombosis was seen in one. Chromophobe renal cell carcinomas of large size tend to have a heterogeneous appearance on post-contrast and T2-weighted images, a well-defined tumor contour with a hypointensity rim on T2-wighted images, and lower enhancement than that of the renal cortex. Tumor necrosis is easily apparent, and ''microscopic fat'' may be observed. (author)

Enhanced axion-photon coupling in GUT with hidden photon

Science.gov (United States)

Daido, Ryuji; Takahashi, Fuminobu; Yokozaki, Norimi

2018-05-01

We show that the axion coupling to photons can be enhanced in simple models with a single Peccei-Quinn field, if the gauge coupling unification is realized by a large kinetic mixing χ = O (0.1) between hypercharge and unbroken hidden U(1)H. The key observation is that the U(1)H gauge coupling should be rather strong to induce such large kinetic mixing, leading to enhanced contributions of hidden matter fields to the electromagnetic anomaly. We find that the axion-photon coupling is enhanced by about a factor of 10-100 with respect to the GUT-axion models with E / N = 8 / 3.

Do large heads enhance stability and restore native anatomy in primary total hip arthroplasty?

Science.gov (United States)

Lombardi, Adolph V; Skeels, Michael D; Berend, Keith R; Adams, Joanne B; Franchi, Orlando J

2011-06-01

Dislocation remains a serious complication in hip arthroplasty. Resurfacing proponents tout anatomic femoral head restoration as an advantage over total hip arthroplasty. However, advances in bearings have expanded prosthetic head options from traditional sizes of 22, 26, 28, and 32 mm to diameters as large as 60 mm. Large heads reportedly enhance stability owing to increased range of motion before impingement and increased jump distance to subluxation. Available larger diameter material combinations include metal- or ceramic-on-highly crosslinked polyethylene and metal-on-metal, each with distinct advantages and disadvantages. We sought to determine (1) if using larger diameter heads has lowered our dislocation rate; and (2) how closely an anatomic metal-on-metal bearing with diameters to 60 mm replicates native femoral head size. We retrospectively reviewed 2020 primary arthroplasties performed with large heads (≥ 36 mm) in 1748 patients and noted dislocation incidence. In a prospective subset of 89 cases using anatomic heads, native femoral head diameter was measured intraoperatively with calipers by an independent observer and later compared with implanted size. One dislocation has occurred in 2020 hips for an incidence of 0.05%. The prosthetic head averaged 0.7 mm larger than the native head with 68 of 89 (76%) reconstructed to within ± 2 mm of native size. Larger diameter heads have contributed to lower dislocation rates and large-diameter metal-on-metal articulation can provide close anatomic restoration in primary THA.

A nonself sugar mimic of the HIV glycan shield shows enhanced antigenicity

Energy Technology Data Exchange (ETDEWEB)

Doores, Katie J.; Fulton, Zara; Hong, Vu; Patel, Mitul K.; Scanlan, Christopher N.; Wormald, Mark R.; Finn, M.G.; Burton, Dennis R.; Wilson, Ian A.; Davis, Benjamin G. (Scripps); (Oxford)

2011-08-24

Antibody 2G12 uniquely neutralizes a broad range of HIV-1 isolates by binding the high-mannose glycans on the HIV-1 surface glycoprotein, gp120. Antigens that resemble these natural epitopes of 2G12 would be highly desirable components for an HIV-1 vaccine. However, host-produced (self)-carbohydrate motifs have been unsuccessful so far at eliciting 2G12-like antibodies that cross-react with gp120. Based on the surprising observation that 2G12 binds nonproteinaceous monosaccharide D-fructose with higher affinity than D-mannose, we show here that a designed set of nonself, synthetic monosaccharides are potent antigens. When introduced to the terminus of the D1 arm of protein glycans recognized by 2G12, their antigenicity is significantly enhanced. Logical variation of these unnatural sugars pinpointed key modifications, and the molecular basis of this increased antigenicity was elucidated using high-resolution crystallographic analyses. Virus-like particle protein conjugates containing such nonself glycans are bound more tightly by 2G12. As immunogens they elicit higher titers of antibodies than those immunogenic conjugates containing the self D1 glycan motif. These antibodies generated from nonself immunogens also cross-react with this self motif, which is found in the glycan shield, when it is presented in a range of different conjugates and glycans. However, these antibodies did not bind this glycan motif when present on gp120.

Large-Scale No-Show Patterns and Distributions for Clinic Operational Research

Directory of Open Access Journals (Sweden)

Michael L. Davies

2016-02-01

Full Text Available Patient no-shows for scheduled primary care appointments are common. Unused appointment slots reduce patient quality of care, access to services and provider productivity while increasing loss to follow-up and medical costs. This paper describes patterns of no-show variation by patient age, gender, appointment age, and type of appointment request for six individual service lines in the United States Veterans Health Administration (VHA. This retrospective observational descriptive project examined 25,050,479 VHA appointments contained in individual-level records for eight years (FY07-FY14 for 555,183 patients. Multifactor analysis of variance (ANOVA was performed, with no-show rate as the dependent variable, and gender, age group, appointment age, new patient status, and service line as factors. The analyses revealed that males had higher no-show rates than females to age 65, at which point males and females exhibited similar rates. The average no-show rates decreased with age until 75–79, whereupon rates increased. As appointment age increased, males and new patients had increasing no-show rates. Younger patients are especially prone to no-show as appointment age increases. These findings provide novel information to healthcare practitioners and management scientists to more accurately characterize no-show and attendance rates and the impact of certain patient factors. Future general population data could determine whether findings from VHA data generalize to others.

Large-Scale No-Show Patterns and Distributions for Clinic Operational Research.

Science.gov (United States)

Davies, Michael L; Goffman, Rachel M; May, Jerrold H; Monte, Robert J; Rodriguez, Keri L; Tjader, Youxu C; Vargas, Dominic L

2016-02-16

Patient no-shows for scheduled primary care appointments are common. Unused appointment slots reduce patient quality of care, access to services and provider productivity while increasing loss to follow-up and medical costs. This paper describes patterns of no-show variation by patient age, gender, appointment age, and type of appointment request for six individual service lines in the United States Veterans Health Administration (VHA). This retrospective observational descriptive project examined 25,050,479 VHA appointments contained in individual-level records for eight years (FY07-FY14) for 555,183 patients. Multifactor analysis of variance (ANOVA) was performed, with no-show rate as the dependent variable, and gender, age group, appointment age, new patient status, and service line as factors. The analyses revealed that males had higher no-show rates than females to age 65, at which point males and females exhibited similar rates. The average no-show rates decreased with age until 75-79, whereupon rates increased. As appointment age increased, males and new patients had increasing no-show rates. Younger patients are especially prone to no-show as appointment age increases. These findings provide novel information to healthcare practitioners and management scientists to more accurately characterize no-show and attendance rates and the impact of certain patient factors. Future general population data could determine whether findings from VHA data generalize to others.

Strong discontinuity with cam clay under large deformations

DEFF Research Database (Denmark)

Katic, Natasa; Hededal, Ole

2008-01-01

The work shows simultaneous implementation of Strong discontinuity approach (SDA) by means of Enhanced Assumed Strain (EAS) and Critical State Soil Mechanics CSSM) in large strain regime. The numerical model is based on an additive decomposition of the displacement gradient into a conforming and ...... and an enhanced part. The localized deformations are approximated by means of a discontinuous displacement field. The applied algorithm leads to a predictor/corrector procedure which is formally identical to the returnmapping algorithm of classical (local and continuous) Cam clay model....

Fast-Valving of Large Steam Turbine Units as a Means of Power System Security Enhancement

Directory of Open Access Journals (Sweden)

Bogdan Sobczak

2014-03-01

Full Text Available Fast-valving assists in maintaining system stability following a severe transmission system fault by reducing the turbine mechanical power. Fast-valving consists in rapid closing and opening of steam valves in an adequate manner to reduce the generator accelerating power following the recognition of a severe fault. FV can be an effective and economical method of meeting the performance requirements of a power system in the presence of an increase in wind and solar generation in the power system, newly connected large thermal units and delaying of building new transmission lines. The principle of fast-valving and advantages of applying this technique in large steam turbine units was presented in the paper. Effectiveness of fast-valving in enhancing the stability of the Polish Power Grid was analyzed. The feasibility study of fast-valving application in the 560 MW unit in Kozienice Power Station (EW SA was discussed.

Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator.

Science.gov (United States)

Wu, Dandan; Ma, Wenhui; Mao, Yingbo; Deng, Jiushuai; Wen, Shuming

2017-05-18

In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The results of ICP analysis indicate that the dissolution of enhanced sulfurized malachite surface is significantly decreased. Zeta potential measurements indicate that a smaller isoelectric point value and a large number of copper-sulfide films formed on the malachite surface by enhancing sulfidation resulted in a large amount of sodium butyl xanthate absorbed onto the enhanced sulfurized malachite surface. EDS semi-quantitative analysis and XPS analysis show that malachite was easily sulfurized by sodium sulfide with ammonium ion. These results show that the addition of ammonium ion plays a significant role in the sulfidation of malachite and results in improved flotation performance.

Self-Assembled Complexes of Horseradish Peroxidase with Magnetic Nanoparticles Showing Enhanced Peroxidase Activity

KAUST Repository

Corgié , Sté phane C.; Kahawong, Patarawan; Duan, Xiaonan; Bowser, Daniel; Edward, Joseph B.; Walker, Larry P.; Giannelis, Emmanuel P.

2012-01-01

Bio-nanocatalysts (BNCs) consisting of horseradish peroxidase (HRP) self-assembled with magnetic nanoparticles (MNPs) enhance enzymatic activity due to the faster turnover and lower inhibition of the enzyme. The size and magnetization of the MNPs

Fault Ride Through Capability Enhancement of a Large-Scale PMSG Wind System with Bridge Type Fault Current Limiters

Directory of Open Access Journals (Sweden)

ALAM, M. S.

2018-02-01

Full Text Available In this paper, bridge type fault current limiter (BFCL is proposed as a potential solution to the fault problems of permanent magnet synchronous generator (PMSG based large-scale wind energy system. As PMSG wind system is more vulnerable to disturbances, it is essential to guarantee the stability during severe disturbances by enhancing the fault ride through capability. BFCL controller has been designed to insert resistance and inductance during the inception of system disturbances in order to limit fault current. Constant capacitor voltage has been maintained by the grid voltage source converter (GVSC controller while current extraction or injection has been achieved by machine VSC (MVSC controller. Symmetrical and unsymmetrical faults have been applied in the system to show the effectiveness of the proposed BFCL solution. PMSG wind system, BFCL and their controllers have been implemented by real time hardware in loop (RTHIL setup with real time digital simulator (RTDS and dSPACE. Another significant feature of this work is that the performance of the proposed BFCL is compared with that of series dynamic braking resistor (SDBR. Comparative RTHIL implementation results show that the proposed BFCL is very efficient in improving system fault ride through capability by limiting the fault current and outperforms SDBR.

Carbon dioxide efficiency of terrestrial enhanced weathering.

Science.gov (United States)

Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

2014-05-06

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

Human behaviour can trigger large carnivore attacks in developed countries.

Science.gov (United States)

Penteriani, Vincenzo; Delgado, María del Mar; Pinchera, Francesco; Naves, Javier; Fernández-Gil, Alberto; Kojola, Ilpo; Härkönen, Sauli; Norberg, Harri; Frank, Jens; Fedriani, José María; Sahlén, Veronica; Støen, Ole-Gunnar; Swenson, Jon E; Wabakken, Petter; Pellegrini, Mario; Herrero, Stephen; López-Bao, José Vicente

2016-02-03

The media and scientific literature are increasingly reporting an escalation of large carnivore attacks on humans in North America and Europe. Although rare compared to human fatalities by other wildlife, the media often overplay large carnivore attacks on humans, causing increased fear and negative attitudes towards coexisting with and conserving these species. Although large carnivore populations are generally increasing in developed countries, increased numbers are not solely responsible for the observed rise in the number of attacks by large carnivores. Here we show that an increasing number of people are involved in outdoor activities and, when doing so, some people engage in risk-enhancing behaviour that can increase the probability of a risky encounter and a potential attack. About half of the well-documented reported attacks have involved risk-enhancing human behaviours, the most common of which is leaving children unattended. Our study provides unique insight into the causes, and as a result the prevention, of large carnivore attacks on people. Prevention and information that can encourage appropriate human behaviour when sharing the landscape with large carnivores are of paramount importance to reduce both potentially fatal human-carnivore encounters and their consequences to large carnivores.

Enhancement of juvenile Caribbean spiny lobsters: an evaluation of changes in multiple response variables with the addition of large artificial shelters.

Science.gov (United States)

Briones-Fourzán, Patricia; Lozano-Alvarez, Enrique; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia

2007-03-01

Shortage of natural crevice shelters may produce population bottlenecks in juvenile Caribbean spiny lobsters (Panulirus argus), a socially gregarious species. We conducted a field experiment to test enhancement of a local population of juvenile P. argus with the addition of artificial shelters ("casitas") that mimic large crevices (1.1 m(2) in surface area and 3.8 cm in height). Changes in density and biomass of juvenile lobsters 15-50 mm carapace length (CL) were assessed with a multiple before-after control-impact (MBACI) analysis. Separate analyses were also conducted on small (15-35 mm CL) and large (35.1-50 mm CL) juveniles to assess size-related effects. First, we carried out 13 lobster surveys on nine fixed 1-ha sites over a shallow reef lagoon ("before" period). Then, we deployed ten casitas in each of five sites and left four sites as controls, and conducted 22 further surveys ("after" period). Deployment of casitas resulted in a sixfold increase in juvenile density (76% contributed by small and 24% by large juveniles) and a sevenfold increase in biomass (40 and 60%, respectively). Capture-recapture results revealed that enhancement was achieved not by promoting individual growth but by increasing survival, persistence, and foraging ranges of small and large juveniles. Casitas both mitigated shortage of natural shelter and increased sociality, allowing for cohabitation of smaller, more vulnerable juveniles with larger conspecifics that have greater defensive abilities. Casitas may help enhance local populations of juvenile P. argus in Caribbean seagrass habitats, typically poor in natural crevice shelters. The use of MBACI and the simultaneous assessment of multiple interrelated response variables may be a powerful analytical approach to test shelter limitation in other species and to examine the function of structural habitat in other systems.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.; Theodorou, I. G.; Centeno, A.; Petrov, P. K.; Alford, N. M.; Ryan, M. P.; Xie, F.

2016-01-01

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.

2016-12-28

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Large enhancements of thermopower and carrier mobility in quantum dot engineered bulk semiconductors.

Science.gov (United States)

Liu, Yuanfeng; Sahoo, Pranati; Makongo, Julien P A; Zhou, Xiaoyuan; Kim, Sung-Joo; Chi, Hang; Uher, Ctirad; Pan, Xiaoqing; Poudeu, Pierre F P

2013-05-22

The thermopower (S) and electrical conductivity (σ) in conventional semiconductors are coupled adversely through the carriers' density (n) making it difficult to achieve meaningful simultaneous improvements in both electronic properties through doping and/or substitutional chemistry. Here, we demonstrate the effectiveness of coherently embedded full-Heusler (FH) quantum dots (QDs) in tailoring the density, mobility, and effective mass of charge carriers in the n-type Ti(0.1)Zr(0.9)NiSn half-Heusler matrix. We propose that the embedded FH QD forms a potential barrier at the interface with the matrix due to the offset of their conduction band minima. This potential barrier discriminates existing charge carriers from the conduction band of the matrix with respect to their relative energy leading to simultaneous large enhancements of the thermopower (up to 200%) and carrier mobility (up to 43%) of the resulting Ti(0.1)Zr(0.9)Ni(1+x)Sn nanocomposites. The improvement in S with increasing mole fraction of the FH-QDs arises from a drastic reduction (up to 250%) in the effective carrier density coupled with an increase in the carrier's effective mass (m*), whereas the surprising enhancement in the mobility (μ) is attributed to an increase in the carrier's relaxation time (τ). This strategy to manipulate the transport behavior of existing ensembles of charge carriers within a bulk semiconductor using QDs is very promising and could pave the way to a new generation of high figure of merit thermoelectric materials.

Live Faecalibacterium prausnitzii Does Not Enhance Epithelial Barrier Integrity in an Apical Anaerobic Co-Culture Model of the Large Intestine

Directory of Open Access Journals (Sweden)

Eva Maier

2017-12-01

Full Text Available Appropriate intestinal barrier maturation during infancy largely depends on colonization with commensal bacteria. Faecalibacterium prausnitzii is an abundant obligate anaerobe that colonizes during weaning and is thought to maintain colonic health throughout life. We previously showed that F. prausnitzii induced Toll-like receptor 2 (TLR2 activation, which is linked to enhanced tight junction formation. Therefore, we hypothesized that F. prausnitzii enhances barrier integrity, an important factor in appropriate intestinal barrier maturation. In order to test metabolically active bacteria, we used a novel apical anaerobic co-culture system that allows the survival of both obligate anaerobic bacteria and oxygen-requiring intestinal epithelial cells (Caco-2. The first aim was to optimize the culture medium to enable growth and active metabolism of F. prausnitzii while maintaining the viability and barrier integrity, as measured by trans-epithelial electrical resistance (TEER, of the Caco-2 cells. This was achieved by supplementing the apical cell culture medium with bacterial culture medium. The second aim was to test the effect of F. prausnitzii on TEER across Caco-2 cell layers. Live F. prausnitzii did not improve TEER, which indicates that its benefits are not via altering tight junction integrity. The optimization of the novel dual-environment co-culturing system performed in this research will enable the investigation of new probiotics originating from indigenous beneficial bacteria.

Live Faecalibacterium prausnitzii Does Not Enhance Epithelial Barrier Integrity in an Apical Anaerobic Co-Culture Model of the Large Intestine.

Science.gov (United States)

Maier, Eva; Anderson, Rachel C; Roy, Nicole C

2017-12-12

Appropriate intestinal barrier maturation during infancy largely depends on colonization with commensal bacteria. Faecalibacterium prausnitzii is an abundant obligate anaerobe that colonizes during weaning and is thought to maintain colonic health throughout life. We previously showed that F. prausnitzii induced Toll-like receptor 2 (TLR2) activation, which is linked to enhanced tight junction formation. Therefore, we hypothesized that F. prausnitzii enhances barrier integrity, an important factor in appropriate intestinal barrier maturation. In order to test metabolically active bacteria, we used a novel apical anaerobic co-culture system that allows the survival of both obligate anaerobic bacteria and oxygen-requiring intestinal epithelial cells (Caco-2). The first aim was to optimize the culture medium to enable growth and active metabolism of F. prausnitzii while maintaining the viability and barrier integrity, as measured by trans-epithelial electrical resistance (TEER), of the Caco-2 cells. This was achieved by supplementing the apical cell culture medium with bacterial culture medium. The second aim was to test the effect of F. prausnitzii on TEER across Caco-2 cell layers. Live F. prausnitzii did not improve TEER, which indicates that its benefits are not via altering tight junction integrity. The optimization of the novel dual-environment co-culturing system performed in this research will enable the investigation of new probiotics originating from indigenous beneficial bacteria.

The Planform Mobility of Large River Channel Confluences

Science.gov (United States)

Sambrook Smith, Greg; Dixon, Simon; Nicholas, Andrew; Bull, Jon; Vardy, Mark; Best, James; Goodbred, Steven; Sarker, Maminul

2017-04-01

Large river confluences are widely acknowledged as exerting a controlling influence upon both upstream and downstream morphology and thus channel planform evolution. Despite their importance, little is known concerning their longer-term evolution and planform morphodynamics, with much of the literature focusing on confluences as representing fixed, nodal points in the fluvial network. In contrast, some studies of large sand bed rivers in India and Bangladesh have shown large river confluences can be highly mobile, although the extent to which this is representative of large confluences around the world is unknown. Confluences have also been shown to generate substantial bed scours, and if the confluence location is mobile these scours could 'comb' across wide areas. This paper presents field data of large confluences morphologies in the Ganges-Brahmaputra-Meghna river basin, illustrating the spatial extent of large river bed scours and showing scour depth can extend below base level, enhancing long term preservation potential. Based on a global review of the planform of large river confluences using Landsat imagery from 1972 to 2014 this study demonstrates such scour features can be highly mobile and there is an array of confluence morphodynamic types: from freely migrating confluences, through confluences migrating on decadal timescales to fixed confluences. Based on this analysis, a conceptual model of large river confluence types is proposed, which shows large river confluences can be sites of extensive bank erosion and avulsion, creating substantial management challenges. We quantify the abundance of mobile confluence types by classifying all large confluences in both the Amazon and Ganges-Brahmaputra-Meghna basins, showing these two large rivers have contrasting confluence morphodynamics. We show large river confluences have multiple scales of planform adjustment with important implications for river management, infrastructure and interpretation of the rock

Process Improvement to Enhance Quality in a Large Volume Labor and Birth Unit.

Science.gov (United States)

Bell, Ashley M; Bohannon, Jessica; Porthouse, Lisa; Thompson, Heather; Vago, Tony

using the Lean process, frontline clinicians identified areas that needed improvement, developed and implemented successful strategies that addressed each gap, and enhanced the quality and safety of care for a large volume perinatal service.

Enhanced 2D-DOA Estimation for Large Spacing Three-Parallel Uniform Linear Arrays

Directory of Open Access Journals (Sweden)

Dong Zhang

2018-01-01

Full Text Available An enhanced two-dimensional direction of arrival (2D-DOA estimation algorithm for large spacing three-parallel uniform linear arrays (ULAs is proposed in this paper. Firstly, we use the propagator method (PM to get the highly accurate but ambiguous estimation of directional cosine. Then, we use the relationship between the directional cosine to eliminate the ambiguity. This algorithm not only can make use of the elements of the three-parallel ULAs but also can utilize the connection between directional cosine to improve the estimation accuracy. Besides, it has satisfied estimation performance when the elevation angle is between 70° and 90° and it can automatically pair the estimated azimuth and elevation angles. Furthermore, it has low complexity without using any eigen value decomposition (EVD or singular value decompostion (SVD to the covariance matrix. Simulation results demonstrate the effectiveness of our proposed algorithm.

Large enhanced dielectric permittivity in polyaniline passivated core-shell nano magnetic iron oxide by plasma polymerization

Energy Technology Data Exchange (ETDEWEB)

Joy, Lija K.; Sooraj, V.; Sethulakshmi, N.; Anantharaman, M. R., E-mail: mraiyer@yahoo.com [Department of Physics, Cochin University of Science and Technology, Cochin-682022, Kerala (India); Sajeev, U. S. [Department of Physics, Government College, Kottayam-686613, Kerala (India); Nair, Swapna S. [Department of Physics, School of Mathematical and Physical Sciences, Central University of Kerala, Kasargode-671123, Kerala (India); Narayanan, T. N. [CSIR-Central Electrochemical Research Institute, Karaikkudi-630006, Tamil Nadu (India); Ajayan, P. M. [Department of Material Science and Nano Engineering, Rice University, 6100 Main Street, Houston, Texas 7700 (United States)

2014-03-24

Commercial samples of Magnetite with size ranging from 25–30 nm were coated with polyaniline by using radio frequency plasma polymerization to achieve a core shell structure of magnetic nanoparticle (core)–Polyaniline (shell). High resolution transmission electron microscopy images confirm the core shell architecture of polyaniline coated iron oxide. The dielectric properties of the material were studied before and after plasma treatment. The polymer coated magnetite particles exhibited a large dielectric permittivity with respect to uncoated samples. The dielectric behavior was modeled using a Maxwell–Wagner capacitor model. A plausible mechanism for the enhancement of dielectric permittivity is proposed.

Real-time simulation of large-scale floods

Science.gov (United States)

Liu, Q.; Qin, Y.; Li, G. D.; Liu, Z.; Cheng, D. J.; Zhao, Y. H.

2016-08-01

According to the complex real-time water situation, the real-time simulation of large-scale floods is very important for flood prevention practice. Model robustness and running efficiency are two critical factors in successful real-time flood simulation. This paper proposed a robust, two-dimensional, shallow water model based on the unstructured Godunov- type finite volume method. A robust wet/dry front method is used to enhance the numerical stability. An adaptive method is proposed to improve the running efficiency. The proposed model is used for large-scale flood simulation on real topography. Results compared to those of MIKE21 show the strong performance of the proposed model.

Conversion of just-continuous metallic films to large particulate substrates for metal-enhanced fluorescence

OpenAIRE

Aslan, Kadir; Malyn, Stuart N.; Zhang, Yongxia; Geddes, Chris D.

2008-01-01

We report the effects of thermally annealing, non-, just-, and thick continuous silver films for their potential applications in metal-enhanced fluorescence, a near-field concept which can alter the free-space absorption and emissive properties of close-proximity fluorophores (excited states). We have chosen to anneal a noncontinuous particulate film 5 nm thick and two thicker continuous films, 15 and 25 nm thick, respectively. Our results show that the annealing of the 25 nm film has little ...

Heliosphere Responds to a Large Solar Wind Intensification: Decisive Observations from IBEX

Science.gov (United States)

McComas, D. J.; Dayeh, M. A.; Funsten, H. O.; Heerikhuisen, J.; Janzen, P. H.; Reisenfeld, D. B.; Schwadron, N. A.; Szalay, J. R.; Zirnstein, E. J.

2018-03-01

Our heliosphere—the bubble in the local interstellar medium produced by the Sun’s outflowing solar wind—has finally responded to a large increase in solar wind output and pressure in the second half of 2014. NASA’s Interstellar Boundary Explorer (IBEX) mission remotely monitors the outer heliosphere by observing energetic neutral atoms (ENAs) returning from the heliosheath, the region between the termination shock and heliopause. IBEX observed a significant enhancement in higher energy ENAs starting in late 2016. While IBEX observations over the previous decade reflected a general reduction of ENA intensities, indicative of a deflating heliosphere, new observations show that the large (∼50%), persistent increase in the solar wind dynamic pressure has modified the heliosheath, producing enhanced ENA emissions. The combination of these new observations with simulation results indicate that this pressure is re-expanding our heliosphere, with the termination shock and heliopause already driven outward in the locations closest to the Sun. The timing between the IBEX observations, a large transient pressure enhancement seen by Voyager 2, and the simulations indicates that the pressure increase propagated through the heliosheath, reflected off the heliopause, and the enhanced density of the solar wind filled the heliosheath behind it before generating significantly enhanced ENA emissions. The coming years should see significant changes in anomalous cosmic rays, galactic cosmic radiation, and the filtration of interstellar neutral atoms into the inner heliosphere.

Automatic tools for enhancing the collaborative experience in large projects

International Nuclear Information System (INIS)

Bourilkov, D; Rodriquez, J L

2014-01-01

With the explosion of big data in many fields, the efficient management of knowledge about all aspects of the data analysis gains in importance. A key feature of collaboration in large scale projects is keeping a log of what is being done and how - for private use, reuse, and for sharing selected parts with collaborators and peers, often distributed geographically on an increasingly global scale. Even better if the log is automatically created on the fly while the scientist or software developer is working in a habitual way, without the need for extra efforts. This saves time and enables a team to do more with the same resources. The CODESH - COllaborative DEvelopment SHell - and CAVES - Collaborative Analysis Versioning Environment System projects address this problem in a novel way. They build on the concepts of virtual states and transitions to enhance the collaborative experience by providing automatic persistent virtual logbooks. CAVES is designed for sessions of distributed data analysis using the popular ROOT framework, while CODESH generalizes the approach for any type of work on the command line in typical UNIX shells like bash or tcsh. Repositories of sessions can be configured dynamically to record and make available the knowledge accumulated in the course of a scientific or software endeavor. Access can be controlled to define logbooks of private sessions or sessions shared within or between collaborating groups. A typical use case is building working scalable systems for analysis of Petascale volumes of data as encountered in the LHC experiments. Our approach is general enough to find applications in many fields.

Listeria monocytogenes strains show large variations in competitive growth in mixed culture biofilms and suspensions with bacteria from food processing environments.

Science.gov (United States)

Heir, Even; Møretrø, Trond; Simensen, Andreas; Langsrud, Solveig

2018-06-20

Interactions and competition between resident bacteria in food processing environments could affect their ability to survive, grow and persist in microhabitats and niches in the food industry. In this study, the competitive ability of L. monocytogenes strains grown together in separate culture mixes with other L. monocytogenes (L. mono mix), L. innocua (Listeria mix), Gram-negative bacteria (Gram- mix) and with a multigenera mix (Listeria + Gram- mix) was investigated in biofilms on stainless steel and in suspensions at 12 °C. The mixed cultures included resident bacteria from processing surfaces in meat and salmon industry represented by L. monocytogenes (n = 6), L. innocua (n = 5) and Gram-negative bacteria (n = 6; Acinetobacter sp., Pseudomonas fragi, Pseudomonas fluorescens, Serratia liquefaciens, Stenotrophomonas maltophilia). Despite hampered in growth in mixed cultures, L. monocytogenes established in biofilms with counts at day nine between 7.3 and 9.0 log per coupon with the lowest counts in the Listeria + G- mix that was dominated by Pseudomonas. Specific L. innocua inhibited growth of L. monocytogenes strains differently; inhibition that was further enhanced by the background Gram-negative microbiota. In these multispecies and multibacteria cultures, the growth competitive effects lead to the dominance of a strong competitor L. monocytogenes strain that was only slightly inhibited by L. innocua and showed strong competitive abilities in mixed cultures with resident Gram-negative bacteria. The results indicates complex patterns of bacterial interactions and L. monocytogenes inhibition in the multibacteria cultures that only partially depend on cell contact and likely involve various antagonistic and bacterial tolerance mechanisms. The study indicates large variations among L. monocytogenes in their competitiveness under multibacterial culture conditions that should be considered in further studies towards understanding of L

Enhanced pairing susceptibility in a photodoped two-orbital Hubbard model

Science.gov (United States)

Werner, Philipp; Strand, Hugo U. R.; Hoshino, Shintaro; Murakami, Yuta; Eckstein, Martin

2018-04-01

Local spin fluctuations provide the glue for orbital-singlet spin-triplet pairing in the doped Mott insulating regime of multiorbital Hubbard models. At large Hubbard repulsion U , the pairing susceptibility is nevertheless tiny because the pairing interaction cannot overcome the suppression of charge fluctuations. Using nonequilibrium dynamical mean field simulations of the two-orbital Hubbard model, we show that out of equilibrium the pairing susceptibility in this large-U regime can be strongly enhanced by creating a photoinduced population of the relevant charge states. This enhancement is supported by the long lifetime of photodoped charge carriers and a built-in cooling mechanism in multiorbital Hubbard systems.

\\psi (2S) enhancement in p-Pb collision as an indication of quark-gluon plasma formation at the Large Hadron Collider

Science.gov (United States)

Ganesh, S.; Singh, R., Captain; Mishra, M.

2018-03-01

Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and Relativistic Heavy-Ion Collider energies for the past several years, as it was thought that quark-gluon plasma (QGP) is not formed in such collisions. However, at the Large Hadron Collider (LHC), there seems a possibility that QGP is formed during proton-lead (p-Pb) collisions. In this work, we have derived an expression for gluon induced excitation of J/\\psi to \\psi (2S), using pNRQCD, and show that the relative enhancement of \\psi (2S) vis-à-vis J/\\psi , especially at high p T , gives further indication that the QGP is indeed formed in p-Pb collisions at the most central collisions at LHC energy. J/\\psi and \\psi (2S) suppression effects seen at ALICE are also qualitatively explained.

Identification of activated enhancers and linked transcription factors in breast, prostate, and kidney tumors by tracing enhancer networks using epigenetic traits.

Science.gov (United States)

Rhie, Suhn Kyong; Guo, Yu; Tak, Yu Gyoung; Yao, Lijing; Shen, Hui; Coetzee, Gerhard A; Laird, Peter W; Farnham, Peggy J

2016-01-01

Although technological advances now allow increased tumor profiling, a detailed understanding of the mechanisms leading to the development of different cancers remains elusive. Our approach toward understanding the molecular events that lead to cancer is to characterize changes in transcriptional regulatory networks between normal and tumor tissue. Because enhancer activity is thought to be critical in regulating cell fate decisions, we have focused our studies on distal regulatory elements and transcription factors that bind to these elements. Using DNA methylation data, we identified more than 25,000 enhancers that are differentially activated in breast, prostate, and kidney tumor tissues, as compared to normal tissues. We then developed an analytical approach called Tracing Enhancer Networks using Epigenetic Traits that correlates DNA methylation levels at enhancers with gene expression to identify more than 800,000 genome-wide links from enhancers to genes and from genes to enhancers. We found more than 1200 transcription factors to be involved in these tumor-specific enhancer networks. We further characterized several transcription factors linked to a large number of enhancers in each tumor type, including GATA3 in non-basal breast tumors, HOXC6 and DLX1 in prostate tumors, and ZNF395 in kidney tumors. We showed that HOXC6 and DLX1 are associated with different clusters of prostate tumor-specific enhancers and confer distinct transcriptomic changes upon knockdown in C42B prostate cancer cells. We also discovered de novo motifs enriched in enhancers linked to ZNF395 in kidney tumors. Our studies characterized tumor-specific enhancers and revealed key transcription factors involved in enhancer networks for specific tumor types and subgroups. Our findings, which include a large set of identified enhancers and transcription factors linked to those enhancers in breast, prostate, and kidney cancers, will facilitate understanding of enhancer networks and mechanisms

Surface-enhanced Raman scattering on gold nanotrenches and nanoholes

KAUST Repository

Yue, Weisheng

2012-04-01

Dependent effects on edge-to-edge distance and incidence polarization in surface-enhanced Raman Scattering (SERS) were studied in detection of 4-mercaptopyridine (4-MPy) molecules absorbed on gold nanotrenches and nanoholes. The gold nanostructures with controllable size and period were fabricated using electron-beam lithography. Large SERS enhancement in detection of 4-MPy molecules on both nanostructred substrates was observed. The SERS enhancement increased exponentially with decrease of edge to-edge distance for both the nanotrenches and nanoholes while keeping the sizes of the nanotrenches and nanoholes unchanged. Investigation of polarization dependence showed that the SERS enhancement of nanotrenches was much more sensitive to the incidence polarizations than that of nanoholes. © 2012 American Scientific Publishers.

Higgs, moduli problem, baryogenesis and large volume compactifications

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [RIKEN Nishina Center, Saitama (Japan). Mathematical Physics Lab.; Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Takahashi, Fuminobu [Tohoku Univ., Sendai (Japan). Dept. of Physics

2012-07-15

We consider the cosmological moduli problem in the context of high-scale supersymmetry breaking suggested by the recent discovery of the standard-model like Higgs boson. In order to solve the notorious moduli-induced gravitino problem, we focus on the LARGE volume scenario, in which the modulus decay into gravitinos can be kinematically forbidden. We then consider the Affleck-Dine mechanism with or without an enhanced coupling with the inflaton, taking account of possible Q-ball formation. We show that the baryon asymmetry of the present Universe can be generated by the Affleck-Dine mechanism in LARGE volume scenario, solving the moduli and gravitino problems.

Higgs, moduli problem, baryogenesis and large volume compactifications

International Nuclear Information System (INIS)

Higaki, Tetsutaro; Takahashi, Fuminobu

2012-07-01

We consider the cosmological moduli problem in the context of high-scale supersymmetry breaking suggested by the recent discovery of the standard-model like Higgs boson. In order to solve the notorious moduli-induced gravitino problem, we focus on the LARGE volume scenario, in which the modulus decay into gravitinos can be kinematically forbidden. We then consider the Affleck-Dine mechanism with or without an enhanced coupling with the inflaton, taking account of possible Q-ball formation. We show that the baryon asymmetry of the present Universe can be generated by the Affleck-Dine mechanism in LARGE volume scenario, solving the moduli and gravitino problems.

Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet.

Science.gov (United States)

Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

2014-02-01

We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11-13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet

Energy Technology Data Exchange (ETDEWEB)

Kimura, Daiju, E-mail: kimura@nf.eie.eng.osaka-u.ac.jp; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2014-02-15

We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11–13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

Polymer film strain gauges for measuring large elongations

Science.gov (United States)

Kondratov, A. P.; Zueva, A. M.; Varakin, R. S.; Taranec, I. P.; Savenkova, I. A.

2018-02-01

The paper shows the possibility to print polymer strain gages, microstrip lines, coplanar waveguides, and other prints for avionics using printing technology and equipment. The methods of screen and inkjet printing have been complemented by three new operations of preparing print films for application of an electrically conductive ink layer. Such additional operations make it possible to enhance the conductive ink layer adhesion to the film and to manufacture strain gages for measuring large elongations.

Enhancing the Economic Value of Large Investments in Sustainable Drainage Systems (SuDS through Inclusion of Ecosystems Services Benefits

Directory of Open Access Journals (Sweden)

Santiago Urrestarazu Vincent

2017-10-01

Full Text Available Although Sustainable Drainage Systems (SuDS are used in cities across the world as effective flood adaptation responses, their economic viability has frequently been questioned. Inclusion of the monetary value of ecosystem services (ES provided by SuDS can increase the rate of return on investments made. Hence, this paper aims at reviewing the enhancement of the economic value of large-scale investments in SuDS through inclusion of ecosystem services. This study focuses on the flood reduction capacity and the ES benefits of green roofs and rain barrels in the combined sewerage network of Montevideo Municipality in Uruguay. The methodology comprises a cost–benefit analysis—with and without monetised ES provided by SuDS—of two drainage network configurations comprising: (i SuDS; and (ii SuDS and detention storage. The optimal drainage design for both these drainage configurations have been determined using SWMM-EA, a tool which uses multi-objective optimisation based evolutionary algorithm (EA and the storm water management model (SWMM. In both design configurations, total benefits comprising both flood reduction and ES benefits are always higher than their costs. The use of storage along with SuDS provides greater benefits with a larger reduction in flooding, and thus is more cost-effective than using SuDS alone. The results show that, for both of the drainage configurations, the larger investments are not beneficial unless ES benefits are taken into account. Hence, it can be concluded that the inclusion of ES benefits is necessary to justify large-scale investments in SuDS.

Gd-enhanced MR imaging of the herniated lumbar disc: patterns of enhancement

International Nuclear Information System (INIS)

Kwag, Hyon Joo; Choi, Hye Young; Kim, Hyae Young; Kim, Yoo Kyung; Kim, Ah Young; Chung, Eun Chul

1995-01-01

The purpose of this study is to describe the patterns of enhancement of the herniated lumbar disc with Gd-DTPA enhanced MR imaging. Out of 65 patients, 103 lumbar discs diagnosed to be herniated by MR image were retrospectively analyzed. The MR imaging was performed with 1.5 T MR unit, using T1-and T2-weighted sagittal and axial spin echo techniques. Contrast-enhanced T1 weighted sagittal and axial images were performed after intravenous injection of Gadopentetate-dimeglumine(Magnevist, Shering) (0.1 mmol/kg). Contrast enhancement was seen in 66 cases(64%). Thirteen cases of bulging disc were not enhanced. Twenty-eight cases of protruded disc showed intraannular enchantment in 23 cases, peripheral linear and irregular enhancement in each of one case, and nonenhancement in three cases. Fifty-seven cases of extruded disc showed irregular enhancement in 14 cases, peripheral linear enhancement in 12 cases, peripheral ring enhancement in five cases and intraannular enhancement in five cases. All five cases of sequestered disc showed peripheral ring enhancement. Protruded discs show intraannular enhancement frequently and sequestered discs usually show peripheral ring enhancement. Enhanced MR imaging may be helpful to evaluate the type of herniated lumbar disc and relationship among disc material, nerve root and thecal sac

PCTRAN enhancement for large break loss of coolant accident concurrent with loss of offsite power in VVER-1000 simulation

Energy Technology Data Exchange (ETDEWEB)

Hadad, Kamal; Esmaeili-Sanjavanmareh, Mansour [Shiraz Univ., Shiraz (Iran, Islamic Republic of). Dept. of Nuclear Engineering

2017-05-15

PCTRAN capability to simulate a large break loss of coolant accident concurrent with the loss of offsite power in Bushehr Nuclear Power Plant is enhanced and investigated. Following the correction of the accident scenario for Bushehr nuclear power plant in PCTRAN, simulation results are compared with the final safety assessment report of that plant. As a result, the primary loop thermal hydraulics parameters including pressure, total flow rates, leakage flow rates and reactor power are in a good agreement with the reference data. Hot and cold leg temperature variations have the same trends as reference data but have a maximum of 80 C disagreement at the transient initiation. The reason for this disagreement is explained and its adjustment is discussed. Improvements of PCTRAN simulator are mainly due to enhancing user control for atmospheric steam dump valve, containment pressure and emergency core cooling systems which are thoroughly described in this paper.

Formation and Evolution of Carbon-Enhanced Metal-Poor Stars

NARCIS (Netherlands)

Abate, C.; Pols, O.R.; Izzard, R.G.

2010-01-01

Very metal-poor stars observed in the Galactic halo constitute a window on the primordial conditions under which the Milky Way was formed. A large fraction of these stars show a great enhancement in the abundance of carbon and other heavy elements. One explanation of this observation is that these

Enhanced attention amplifies face adaptation.

Science.gov (United States)

Rhodes, Gillian; Jeffery, Linda; Evangelista, Emma; Ewing, Louise; Peters, Marianne; Taylor, Libby

2011-08-15

Perceptual adaptation not only produces striking perceptual aftereffects, but also enhances coding efficiency and discrimination by calibrating coding mechanisms to prevailing inputs. Attention to simple stimuli increases adaptation, potentially enhancing its functional benefits. Here we show that attention also increases adaptation to faces. In Experiment 1, face identity aftereffects increased when attention to adapting faces was increased using a change detection task. In Experiment 2, figural (distortion) face aftereffects increased when attention was increased using a snap game (detecting immediate repeats) during adaptation. Both were large effects. Contributions of low-level adaptation were reduced using free viewing (both experiments) and a size change between adapt and test faces (Experiment 2). We suggest that attention may enhance adaptation throughout the entire cortical visual pathway, with functional benefits well beyond the immediate advantages of selective processing of potentially important stimuli. These results highlight the potential to facilitate adaptive updating of face-coding mechanisms by strategic deployment of attentional resources. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mixed P25 nanoparticles and large rutile particles as a top scattering layer to enhance performance of nanocrystalline TiO{sub 2} based dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiaohua, E-mail: mksxh@163.com; Zhou, Xin; Xu, Yalong; Sun, Panpan; Huang, Niu; Sun, Yihua

2015-05-15

Graphical abstract: - Highlights: • Mixed P25 nanoparticles and large rutile particles were employed to form a top scattering layer. • The top scattering layer exhibits superior light scattering effect. • The bottom nanocrystalline TiO{sub 2} layer can make good use of the back-scattered light. • Bilayer TiO{sub 2} photoanode shows faster interfacial electron transfer and slower charge recombination process. • Bilayer photoanode enhances the DSSC efficiency by a factor of 25%. - Abstract: Herein, we report a bilayer TiO{sub 2} photoanode composed of nanocrystalline TiO{sub 2} (NCT) bottom layer and mixed P25 nanoparticles and large rutile particles (PR) top scattering layer. The present structure performs well in solar light harvesting which is mainly attributed to the fact that the top scattering layer exhibits superior light scattering effect and meanwhile the NCT bottom layer with large dye-loading capacity can make better use of the back-scattered light. Moreover, electrochemical impedance spectroscopy and open circuit voltage decay measurements demonstrate that DSSC based on bilayer photoanode shows faster interfacial electron transfer and slower charge recombination process than that based on NCT monolayer photoanode. These advantages render the DSSCs based on NCT-PR bilayer photoanode exhibiting superior performance under AM1.5G simulated solar irradiation. As an example, by tuning mass ratio between P25 nanoparticles and large rutile particles in the top scattering layer, the DSSC based on NCT-PR bilayer photoanode exhibits an optimum solar energy conversion efficiency of 9.0%, which is about 1.25 times higher than that of monolayer NCT device (7.2%) with the same film thickness.

Simultaneous effect of modified gravity and primordial non-Gaussianity in large scale structure observations

International Nuclear Information System (INIS)

Mirzatuny, Nareg; Khosravi, Shahram; Baghram, Shant; Moshafi, Hossein

2014-01-01

In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in f(R) framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale dependent bias and growth rate functions. The deviation from ΛCDM in the case of primordial non-Gaussian models is in large scales, while the growth rate deviates from ΛCDM in small scales for modified gravity theories. We show that the redshift space distortion can be used to distinguish positive and negative f NL in standard background, while in f(R) theories they are not easily distinguishable. The galaxy power spectrum is generally enhanced in presence of non-Gaussianity and modified gravity. We also obtain the scale dependence of this enhancement. Finally we define galaxy growth rate and galaxy growth rate bias as new observational parameters to constrain cosmology

Enhanced sources of acoustic power surrounding AR 11429

International Nuclear Information System (INIS)

Donea, Alina; Hanson, Christopher

2013-01-01

Multi-frequency power maps of the local acoustic oscillations show acoustic enhancements (''acoustic-power halos'') at high frequencies surrounding large active region. Computational seismic holography reveals a high-frequency ''acoustic-emission halo'', or ''seismic glory'' surrounding large active regions. In this study, we have applied computational seismic holography to map the seismic seismic source density surrounding AR 11429. Studies of HMI/SDO Doppler data, shows that the ''acoustic halos'' and the ''seismic glories'' are prominent at high frequencies 5–8 mHz. We investigate morphological properties of acoustic-power and acoustic emission halos around an active region to see if they are spatially correlated. Details about the local magnetic field from vectormagnetograms of AR 11429 are included. We identify a 15'' region of seismic deficit power (dark moat) shielding the white-light boundary of the active region. The size of the seismic moat is related to region of intermediate magnetic field strength. The acoustic moat is circled by the halo of enhanced seismic amplitude as well as enhanced seismic emission. Overall, the results suggest that features are related. However, if we narrow the frequency band to 5.5 – 6.5 mHz, we find that the seismic source density dominates over the local acoustic power, suggesting the existence of sources that emit more energy downward into the solar interior than upward toward the solar surface.

Survey and research for the enhancement of large-scale technology development 2. How large-scale technology development should be in the future; Ogata gijutsu kaihatsu suishin no tame no chosa kenkyu. 2. Kongo no ogata gijutsu kaihatsu no arikata

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

A survey is conducted over the subject matter by holding interviews with people, employed with the entrusted businesses participating in the large-scale industrial technology development system, who are engaged in the development of industrial technologies, and with people of experience or academic background involved in the project enhancement effort. Needs of improvement are pointed out that the competition principle based for example on parallel development be introduced; that research-on-research be practiced for effective task institution; midway evaluation be substantiated since prior evaluation is difficult; efforts be made to organize new industries utilizing the fruits of large-scale industrial technology for the creation of markets, not to induce economic conflicts; that transfer of technologies be enhanced from the private sector to public sector. Studies are made about the review of research conducting systems; utilization of the power of private sector research and development efforts; enlightening about industrial proprietorship; and the diffusion of large-scale project systems. In this connection, problems are pointed out, requests are submitted, and remedial measures and suggestions are presented. (NEDO)

Substructure boosts to dark matter annihilation from Sommerfeld enhancement

International Nuclear Information System (INIS)

Bovy, Jo

2009-01-01

The recently introduced Sommerfeld enhancement of the dark matter annihilation cross section has important implications for the detection of dark matter annihilation in subhalos in the Galactic halo. In addition to the boost to the dark matter annihilation cross section from the high densities of these subhalos with respect to the main halo, an additional boost caused by the Sommerfeld enhancement results from the fact that they are kinematically colder than the Galactic halo. If we further believe the generic prediction of the cold dark matter paradigm that in each subhalo there is an abundance of substructure which is approximately self-similar to that of the Galactic halo, then I show that additional boosts coming from the density enhancements of these small substructures and their small velocity dispersions enhance the dark matter annihilation cross section even further. I find that very large boost factors (10 5 to 10 9 ) are obtained in a large class of models. The implications of these boost factors for the detection of dark matter annihilation from dwarf spheroidal galaxies in the Galactic halo are such that, generically, they outshine the background gamma-ray flux and are detectable by the Fermi Gamma-ray Space Telescope.

Large enhancement of radiative strength for soft transitions in the quasicontinuum.

Science.gov (United States)

Voinov, A; Algin, E; Agvaanluvsan, U; Belgya, T; Chankova, R; Guttormsen, M; Mitchell, G E; Rekstad, J; Schiller, A; Siem, S

2004-10-01

Radiative strength functions (RSFs) for the (56,57)Fe nuclei below the separation energy are obtained from the 57Fe(3He,alphagamma)56Fe and 57Fe(3He,3He'gamma)57Fe reactions, respectively. An enhancement of more than a factor of 10 over common theoretical models of the soft (E(gamma) less than or approximately equal 2 MeV) RSF for transitions in the quasicontinuum (several MeV above the yrast line) is observed. Two-step cascade intensities with soft primary transitions from the 56Fe(n,2gamma)57Fe reaction confirm the enhancement.

Enhanced ICP for the Registration of Large-Scale 3D Environment Models: An Experimental Study

Directory of Open Access Journals (Sweden)

Jianda Han

2016-02-01

Full Text Available One of the main applications of mobile robots is the large-scale perception of the outdoor environment. One of the main challenges of this application is fusing environmental data obtained by multiple robots, especially heterogeneous robots. This paper proposes an enhanced iterative closest point (ICP method for the fast and accurate registration of 3D environmental models. First, a hierarchical searching scheme is combined with the octree-based ICP algorithm. Second, an early-warning mechanism is used to perceive the local minimum problem. Third, a heuristic escape scheme based on sampled potential transformation vectors is used to avoid local minima and achieve optimal registration. Experiments involving one unmanned aerial vehicle and one unmanned surface vehicle were conducted to verify the proposed technique. The experimental results were compared with those of normal ICP registration algorithms to demonstrate the superior performance of the proposed method.

Sustainability of small reservoirs and large scale water availability under current conditions and climate change

OpenAIRE

Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

2011-01-01

Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts of small reservoirs are subject to climate change. Using a case-study on North-East Brazil, this paper shows that climate change impacts on water availability may be severe, and impacts on distrib...

Global analysis of seagrass restoration: the importance of large-scale planting

KAUST Repository

van Katwijk, Marieke M.; Thorhaug, Anitra; Marbà , Nú ria; Orth, Robert J.; Duarte, Carlos M.; Kendrick, Gary A.; Althuizen, Inge H. J.; Balestri, Elena; Bernard, Guillaume; Cambridge, Marion L.; Cunha, Alexandra; Durance, Cynthia; Giesen, Wim; Han, Qiuying; Hosokawa, Shinya; Kiswara, Wawan; Komatsu, Teruhisa; Lardicci, Claudio; Lee, Kun-Seop; Meinesz, Alexandre; Nakaoka, Masahiro; O'Brien, Katherine R.; Paling, Erik I.; Pickerell, Chris; Ransijn, Aryan M. A.; Verduin, Jennifer J.

2015-01-01

In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta-analysis shows that both trial survival and seagrass population growth rate in trials that survived are positively affected by the number of plants or seeds initially transplanted. This relationship between restoration scale and restoration success was not related to trial characteristics of the initial restoration. The majority of the seagrass restoration trials have been very small, which may explain the low overall trial survival rate (i.e. estimated 37%). Successful regrowth of the foundation seagrass species appears to require crossing a minimum threshold of reintroduced individuals. Our study provides the first global field evidence for the requirement of a critical mass for recovery, which may also hold for other foundation species showing strong positive feedback to a dynamic environment. Synthesis and applications. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting

Global analysis of seagrass restoration: the importance of large-scale planting

KAUST Repository

van Katwijk, Marieke M.

2015-10-28

In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta-analysis shows that both trial survival and seagrass population growth rate in trials that survived are positively affected by the number of plants or seeds initially transplanted. This relationship between restoration scale and restoration success was not related to trial characteristics of the initial restoration. The majority of the seagrass restoration trials have been very small, which may explain the low overall trial survival rate (i.e. estimated 37%). Successful regrowth of the foundation seagrass species appears to require crossing a minimum threshold of reintroduced individuals. Our study provides the first global field evidence for the requirement of a critical mass for recovery, which may also hold for other foundation species showing strong positive feedback to a dynamic environment. Synthesis and applications. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting

Solving very large scattering problems using a parallel PWTD-enhanced surface integral equation solver

KAUST Repository

Liu, Yang

2013-07-01

The computational complexity and memory requirements of multilevel plane wave time domain (PWTD)-accelerated marching-on-in-time (MOT)-based surface integral equation (SIE) solvers scale as O(NtNs(log 2)Ns) and O(Ns 1.5); here N t and Ns denote numbers of temporal and spatial basis functions discretizing the current [Shanker et al., IEEE Trans. Antennas Propag., 51, 628-641, 2003]. In the past, serial versions of these solvers have been successfully applied to the analysis of scattering from perfect electrically conducting as well as homogeneous penetrable targets involving up to Ns ≈ 0.5 × 106 and Nt ≈ 10 3. To solve larger problems, parallel PWTD-enhanced MOT solvers are called for. Even though a simple parallelization strategy was demonstrated in the context of electromagnetic compatibility analysis [M. Lu et al., in Proc. IEEE Int. Symp. AP-S, 4, 4212-4215, 2004], by and large, progress in this area has been slow. The lack of progress can be attributed wholesale to difficulties associated with the construction of a scalable PWTD kernel. © 2013 IEEE.

Fluorescence-enhanced optical imaging in large tissue volumes using a gain-modulated ICCD camera

International Nuclear Information System (INIS)

Godavarty, Anuradha; Eppstein, Margaret J; Zhang, Chaoyang; Theru, Sangeeta; Thompson, Alan B; Gurfinkel, Michael; Sevick-Muraca, Eva M

2003-01-01

A novel image-intensified charge-coupled device (ICCD) imaging system has been developed to perform 3D fluorescence tomographic imaging in the frequency-domain using near-infrared contrast agents. The imager is unique since it (i) employs a large tissue-mimicking phantom, which is shaped and sized to resemble a female breast and part of the extended chest-wall region, and (ii) enables rapid data acquisition in the frequency-domain by using a gain-modulated ICCD camera. Diffusion model predictions are compared to experimental measurements using two different referencing schemes under two different experimental conditions of perfect and imperfect uptake of fluorescent agent into a target. From these experimental measurements, three-dimensional images of fluorescent absorption were reconstructed using a computationally efficient variant of the approximate extended Kalman filter algorithm. The current work represents the first time that 3D fluorescence-enhanced optical tomographic reconstructions have been achieved from experimental measurements of the time-dependent light propagation on a clinically relevant breast-shaped tissue phantom using a gain-modulated ICCD camera

Transudative vs exudative pleural effusions: differentiation using Gd-DTPA-enhanced MRI

International Nuclear Information System (INIS)

Frola, C.; Cantoni, S.; Turtulici, I.; Leoni, C.; Loria, F.; Gaeta, M.; Derchi, L.E.

1997-01-01

The aim of this study was to investigate the capability of Gd-DTPA-enhanced MRI to differentiate between exudative and transudative pleural effusions. An MRI examination was performed on 22 patients with different types of pleural effusion (10 transudative and 12 exudative effusions). T1-weighted SE images were obtained before and 20 min after administration of Gd-DTPA (0.1 mmol/kg). The degree of enhancement of pleural effusions was evaluated both by visual assessement and by quantitative analysis of images. None of 10 transudative effusions showed significative enhancement, whereas 10 of 12 exudative effusions showed enhancement (sensitivity 83 %, specificity 100 %, positive predictive value 100 %). The postcontrast signal intensity ratios (SIRs) of exudates were significantly higher than corresponding precontrast ratios (P = 0.0109) and the postcontrast SIRs of exudates were significantly higher than those of transudates (P = 0.0300). Exudative pleural effusions show a significant enhancement following administration of Gd-DTPA. We presume that this may be caused by increased pleural permeability and more rapid passage of a large amount of Gd-DTPA from the blood into the pleural fluid in case of exudative effusions. In our limited group of patients, signal enhancement proved the presence of an exudative effusion. Absence of signal enhancement suggests a transudate, but does not exclude an exudate. (orig.). With 5 figs., 2 tabs

Surface-enhanced Raman scattering from silver electrodes

International Nuclear Information System (INIS)

Trott, G.R.

1982-01-01

The chemical and physical origins of the anomalously large enhancement of the Raman scattering cross section for molecules adsorbed on silver electrodes in an electrochemical cell were investigated. The effect of the chemical reactions which occur during the anodization/activation procedure were studied using the Ag-CN system. It was shown that the function of the anodization process is to roughen the electrode surface and create an activated site for bonding to the cyanide. A new nonelectrochemical technique for activating the silver surface, along with a study of the enhanced cyanide Raman scattering in different background electrolytes, showed that the Raman active entity on the surface must be a silver-cyanide complex. In order to study the physical mechanism of the enhancement, the angular dependence of the scattered radiation was measured from pyridine adsorbed on an evaporated silver electrode. Both polycrystalline and single crystalline silver films were used. The angular dependence of the scattered radiation from these films showed that the metal surface was controlling the directional properties of the scattered radiation, and not the polarizability tensor of the adsorbate. Based on these experimental results, it was concluded that for weakly roughened silver electrodes the source of the anomalous enhancement is due to a resonant Raman scattering process

The 130 GeV gamma-ray line and Sommerfeld enhancements

International Nuclear Information System (INIS)

Chen, Jing; Zhou, Yu-Feng

2013-01-01

Recently, possible indications of line spectral features in the Fermi-LAT photon spectrum towards the galactic center have been reported. If the distinct line features arise from dark matter (DM) annihilation into γX(X = γ,Z 0 or h 0 ), the corresponding annihilation cross-section is unnaturally large for typical loop-induced radiative processes. On the other hand, it is still too small to be responsible for the observed DM relic density. We show that the mechanism of Sommerfeld enhancement with scalar force-carrier can provide a simple solution to these puzzles. The possibly large Sommerfeld enhancement of the cross-section for s-wave DM annihilation can significantly reduce the required effective couplings between DM and charged particles in typical loop diagrams. The DM particles necessarily annihilate into scalar force-carriers through tree-level p-wave process, which can dominate the total DM annihilation cross-section at freeze out, resulting in the correct thermal relic density, but has subdominant contributions to the DM annihilation today due to velocity suppression. We perform detailed analysis on the effects of p-wave Sommerfeld enhancement on freeze out. The results show that with the constraints from the thermal relic density, the required effective couplings can be reduced by an order of magnitude

Fluorescence Enhancement on Large Area Self-Assembled Plasmonic-3D Photonic Crystals.

Science.gov (United States)

Chen, Guojian; Wang, Dongzhu; Hong, Wei; Sun, Lu; Zhu, Yongxiang; Chen, Xudong

2017-03-01

Discontinuous plasmonic-3D photonic crystal hybrid structures are fabricated in order to evaluate the coupling effect of surface plasmon resonance and the photonic stop band. The nanostructures are prepared by silver sputtering deposition on top of hydrophobic 3D photonic crystals. The localized surface plasmon resonance of the nanostructure has a symbiotic relationship with the 3D photonic stop band, leading to highly tunable characteristics. Fluorescence enhancements of conjugated polymer and quantum dot based on these hybrid structures are studied. The maximum fluorescence enhancement for the conjugated polymer of poly(5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene) potassium salt by a factor of 87 is achieved as compared with that on a glass substrate due to the enhanced near-field from the discontinuous plasmonic structures, strong scattering effects from rough metal surface with photonic stop band, and accelerated decay rates from metal-coupled excited state of the fluorophore. It is demonstrated that the enhancement induced by the hybrid structures has a larger effective distance (optimum thickness ≈130 nm) than conventional plasmonic systems. It is expected that this approach has tremendous potential in the field of sensors, fluorescence-imaging, and optoelectronic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Risk Aversion in Game Shows

DEFF Research Database (Denmark)

Andersen, Steffen; Harrison, Glenn W.; Lau, Morten I.

2008-01-01

We review the use of behavior from television game shows to infer risk attitudes. These shows provide evidence when contestants are making decisions over very large stakes, and in a replicated, structured way. Inferences are generally confounded by the subjective assessment of skill in some games......, and the dynamic nature of the task in most games. We consider the game shows Card Sharks, Jeopardy!, Lingo, and finally Deal Or No Deal. We provide a detailed case study of the analyses of Deal Or No Deal, since it is suitable for inference about risk attitudes and has attracted considerable attention....

Hierarchical ZnO microspheres built by sheet-like network: Large-scale synthesis and structurally enhanced catalytic performances

International Nuclear Information System (INIS)

Zhu Guoxing; Liu Yuanjun; Ji Zhenyuan; Bai Song; Shen Xiaoping; Xu Zheng

2012-01-01

Highlights: ► Hierarchical ZnO microspheres were prepared through a facile precursor procedure in the absence of self-assembled templates, organic additives, or matrices. ► The building blocks of microspheres, sheet-like ZnO networks, are porous mesocrystal terminated with (0 1 −1 0) crystal planes. ► The hierarchical ZnO microsphere catalyst exhibits structure-induced enhancement of catalytic performance and a strong durability. - Abstract: Large-scale novel hierarchical ZnO microspheres were fabricated by a facile precursor procedure in the absence of self-assembled templates, organic additives, or matrices. A field emission scanning electron microscopy (FESEM) image reveals that the ZnO microspheres with diameter of 5–18 μm are built by sheet-like ZnO networks with average thickness of 40 nm and length of several microns. High resolution transmission electron microscopy (HRTEM) image indicates that the building blocks, sheet-like ZnO networks, are porous mesocrystal terminated with {0 1 −1 0} crystal planes. A potential application of the ZnO microspheres as a catalyst in the synthesis of 5-substituted 1H-tetrazoles was investigated. It was found that the hierarchical ZnO microsphere catalyst exhibits structure-induced enhancement of catalytic performance and a strong durability.

The journey from texting to applications on personally owned devices to enhance student eEngagement in large lectures: A pilot study

Directory of Open Access Journals (Sweden)

Trevor Nesbit

Full Text Available Increasing class sizes to gain economies of scale have resulted in less interaction between lecturers and students during lectures. This paper presented the results of a pilot study that set out to examine the use of applications on personally owned devices (APODs to enhance student interaction, participation and engagement in large lectures. The pilot study commences with the development and trial of a text messaging based application, and after a survey of students regarding ownership levels of mobile devices, concludes with the trial of an application developed for mobile devices. The conclusions of the paper highlight that the use of APODs can significantly increase student interaction, participation and engagement in large lectures and identifies implications and opportunities for further research.

Reynolds-number dependence of turbulence enhancement on collision growth

Directory of Open Access Journals (Sweden)

R. Onishi

2016-10-01

Full Text Available This study investigates the Reynolds-number dependence of turbulence enhancement on the collision growth of cloud droplets. The Onishi turbulent coagulation kernel proposed in Onishi et al. (2015 is updated by using the direct numerical simulation (DNS results for the Taylor-microscale-based Reynolds number (Reλ up to 1140. The DNS results for particles with a small Stokes number (St show a consistent Reynolds-number dependence of the so-called clustering effect with the locality theory proposed by Onishi et al. (2015. It is confirmed that the present Onishi kernel is more robust for a wider St range and has better agreement with the Reynolds-number dependence shown by the DNS results. The present Onishi kernel is then compared with the Ayala–Wang kernel (Ayala et al., 2008a; Wang et al., 2008. At low and moderate Reynolds numbers, both kernels show similar values except for r2 ∼ r1, for which the Ayala–Wang kernel shows much larger values due to its large turbulence enhancement on collision efficiency. A large difference is observed for the Reynolds-number dependences between the two kernels. The Ayala–Wang kernel increases for the autoconversion region (r1, r2 < 40 µm and for the accretion region (r1 < 40 and r2 > 40 µm; r1 > 40 and r2 < 40 µm as Reλ increases. In contrast, the Onishi kernel decreases for the autoconversion region and increases for the rain–rain self-collection region (r1, r2 > 40 µm. Stochastic collision–coalescence equation (SCE simulations are also conducted to investigate the turbulence enhancement on particle size evolutions. The SCE with the Ayala–Wang kernel (SCE-Ayala and that with the present Onishi kernel (SCE-Onishi are compared with results from the Lagrangian Cloud Simulator (LCS; Onishi et al., 2015, which tracks individual particle motions and size evolutions in homogeneous isotropic turbulence. The SCE-Ayala and SCE-Onishi kernels show consistent

Quick Mining of Isomorphic Exact Large Patterns from Large Graphs

KAUST Repository

Almasri, Islam

2014-12-01

The applications of the sub graph isomorphism search are growing with the growing number of areas that model their systems using graphs or networks. Specifically, many biological systems, such as protein interaction networks, molecular structures and protein contact maps, are modeled as graphs. The sub graph isomorphism search is concerned with finding all sub graphs that are isomorphic to a relevant query graph, the existence of such sub graphs can reflect on the characteristics of the modeled system. The most computationally expensive step in the search for isomorphic sub graphs is the backtracking algorithm that traverses the nodes of the target graph. In this paper, we propose a pruning approach that is inspired by the minimum remaining value heuristic that achieves greater scalability over large query and target graphs. Our testing on various biological networks shows that performance enhancement of our approach over existing state-of-the-art approaches varies between 6x and 53x. © 2014 IEEE.

Quick Mining of Isomorphic Exact Large Patterns from Large Graphs

KAUST Repository

Almasri, Islam; Gao, Xin; Fedoroff, Nina V.

2014-01-01

The applications of the sub graph isomorphism search are growing with the growing number of areas that model their systems using graphs or networks. Specifically, many biological systems, such as protein interaction networks, molecular structures and protein contact maps, are modeled as graphs. The sub graph isomorphism search is concerned with finding all sub graphs that are isomorphic to a relevant query graph, the existence of such sub graphs can reflect on the characteristics of the modeled system. The most computationally expensive step in the search for isomorphic sub graphs is the backtracking algorithm that traverses the nodes of the target graph. In this paper, we propose a pruning approach that is inspired by the minimum remaining value heuristic that achieves greater scalability over large query and target graphs. Our testing on various biological networks shows that performance enhancement of our approach over existing state-of-the-art approaches varies between 6x and 53x. © 2014 IEEE.

Large thermoelectric power factor in Pr-doped SrTiO3-δ ceramics via grain-boundary-induced mobility enhancement

KAUST Repository

Mehdizadeh Dehkordi, Arash

2014-04-08

We report a novel synthesis strategy to prepare high-performance bulk polycrystalline Pr-doped SrTiO3 ceramics. A large thermoelectric power factor of 1.3 W m-1 K-1 at 500 °C is achieved in these samples. In-depth investigations of the electronic transport and microstructure suggest that this significant improvement results from a substantial enhancement in carrier mobility originating from the formation of Pr-rich grain boundaries. This work provides new directions to higher performance oxide thermoelectrics as well as possibly other properties and applications of this broadly functional perovskite material. © 2014 American Chemical Society.

Large thermoelectric power factor in Pr-doped SrTiO3-δ ceramics via grain-boundary-induced mobility enhancement

KAUST Repository

Mehdizadeh Dehkordi, Arash; Bhattacharya, Sriparna K.; Darroudi, Taghi; Graff, Jennifer W.; Schwingenschlö gl, Udo; Alshareef, Husam N.; Tritt, Terry M.

2014-01-01

We report a novel synthesis strategy to prepare high-performance bulk polycrystalline Pr-doped SrTiO3 ceramics. A large thermoelectric power factor of 1.3 W m-1 K-1 at 500 °C is achieved in these samples. In-depth investigations of the electronic transport and microstructure suggest that this significant improvement results from a substantial enhancement in carrier mobility originating from the formation of Pr-rich grain boundaries. This work provides new directions to higher performance oxide thermoelectrics as well as possibly other properties and applications of this broadly functional perovskite material. © 2014 American Chemical Society.

Highly Enhanced Electromechanical Stability of Large-Area Graphene with Increased Interfacial Adhesion Energy by Electrothermal-Direct Transfer for Transparent Electrodes.

Science.gov (United States)

Kim, Jangheon; Kim, Gi Gyu; Kim, Soohyun; Jung, Wonsuk

2016-09-07

Graphene, a two-dimensional sheet of carbon atoms in a hexagonal lattice structure, has been extensively investigated for research and industrial applications as a promising material with outstanding electrical, mechanical, and chemical properties. To fabricate graphene-based devices, graphene transfer to the target substrate with a clean and minimally defective surface is the first step. However, graphene transfer technologies require improvement in terms of uniform transfer with a clean, nonfolded and nontorn area, amount of defects, and electromechanical reliability of the transferred graphene. More specifically, uniform transfer of a large area is a key challenge when graphene is repetitively transferred onto pretransferred layers because the adhesion energy between graphene layers is too low to ensure uniform transfer, although uniform multilayers of graphene have exhibited enhanced electrical and optical properties. In this work, we developed a newly suggested electrothermal-direct (ETD) transfer method for large-area high quality monolayer graphene with less defects and an absence of folding or tearing of the area at the surface. This method delivers uniform multilayer transfer of graphene by repetitive monolayer transfer steps based on high adhesion energy between graphene layers and the target substrate. To investigate the highly enhanced electromechanical stability, we conducted mechanical elastic bending experiments and reliability tests in a highly humid environment. This ETD-transferred graphene is expected to replace commercial transparent electrodes with ETD graphene-based transparent electrodes and devices such as a touch panels with outstanding electromechanical stability.

Large deformation frictional contact analysis with immersed boundary method

Science.gov (United States)

Navarro-Jiménez, José Manuel; Tur, Manuel; Albelda, José; Ródenas, Juan José

2018-01-01

This paper proposes a method of solving 3D large deformation frictional contact problems with the Cartesian Grid Finite Element Method. A stabilized augmented Lagrangian contact formulation is developed using a smooth stress field as stabilizing term, calculated by Zienckiewicz and Zhu Superconvergent Patch Recovery. The parametric definition of the CAD surfaces (usually NURBS) is considered in the definition of the contact kinematics in order to obtain an enhanced measure of the contact gap. The numerical examples show the performance of the method.

A Wavelet-Enhanced PWTD-Accelerated Time-Domain Integral Equation Solver for Analysis of Transient Scattering from Electrically Large Conducting Objects

KAUST Repository

Liu, Yang

2018-02-26

A wavelet-enhanced plane-wave time-domain (PWTD) algorithm for efficiently and accurately solving time-domain surface integral equations (TD-SIEs) on electrically large conducting objects is presented. The proposed scheme reduces the memory requirement and computational cost of the PWTD algorithm by representing the PWTD ray data using local cosine wavelet bases (LCBs) and performing PWTD operations in the wavelet domain. The memory requirement and computational cost of the LCB-enhanced PWTD-accelerated TD-SIE solver, when applied to the analysis of transient scattering from smooth quasi-planar objects with near-normal incident pulses, scale nearly as O(Ns log Ns) and O(Ns 1.5 ), respectively. Here, Ns denotes the number of spatial unknowns. The efficiency and accuracy of the proposed scheme are demonstrated through its applications to the analysis of transient scattering from a 185 wave-length-long NASA almond and a 123-wavelength long Air-bus-A320 model.

Assessment of the ring enhancement of the brain abscess by computerized tomography

International Nuclear Information System (INIS)

Tanaka, Keisei; Yasunaga, Akio; Kawano, Teruaki; Miyazaki, Hisaya; Mori, Kazuo

1982-01-01

The underlying mechanism concerning the ring enhancement of the CT scan was considered in three cases of brain abscess. The first case, a 55-year-old male, was admitted 1 week after the onset of symptoms. A CT scan showed a contrast ring enhancement with perifocal severe edema in the right temporal lobe. A subsequent CT scan, after the administration of antibiotics and steroid treatment, showed no contrast ring enhancement. However, it reappeared after discontinuation of treatment and the disappeared again following the readministration of antibiotics. In the acute stage, functional changes in the local vessels (failure of BBB) caused by inflammation might have been responsible for the ring enhancement. The second case, an 8-year-old girl, was abmitted 1 month after the onset of symptoms. An initial CT scan showed large lobulated abscesses in the right fronto-temporal lobe, with ring enhancement. The follow-up CT scans, one and two years after onset, still showed a small disc enhancement in the temporallobe. The third case, a 10-year-old boy with tetoralogy of Fallot, developed multiple cerebral abscesses in the left frontal lobe. In spite of medical treatment, his clinical status and CT findings did not show any remarkable inprovement, and so an extracapsular excision of the abscesses was performed. Serial CT scans. however, revealed the persistence of the ring sign even after a complete excision of the brain abscesses. Microscopic findings of the excised abscess wall showed a marked, vascular-rich granulation, the outer part of which remained in situ and must have been responsible for the ring enhancement even after the extracapsular excision of the brain abscesses. (author)

A novel large deletion of the ICR1 region including H19 and putative enhancer elements.

Science.gov (United States)

Fryssira, Helen; Amenta, Stella; Kanber, Deniz; Sofocleous, Christalena; Lykopoulou, Evangelia; Kanaka-Gantenbein, Christina; Cerrato, Flavia; Lüdecke, Hermann-Josef; Bens, Susanne; Riccio, Andrea; Buiting, Karin

2015-05-06

Beckwith-Wiedemann syndrome (BWS) is a rare pediatric overgrowth disorder with a variable clinical phenotype caused by deregulation affecting imprinted genes in the chromosomal region 11p15. Alterations of the imprinting control region 1 (ICR1) at the IGF2/H19 locus resulting in biallelic expression of IGF2 and biallelic silencing of H19 account for approximately 10% of patients with BWS. The majority of these patients have epimutations of the ICR1 without detectable DNA sequence changes. Only a few patients were found to have deletions. Most of these deletions are small affecting different parts of the ICR1 differentially methylated region (ICR1-DMR) removing target sequences for CTCF. Only a very few deletions reported so far include the H19 gene in addition to the CTCF binding sites. None of these deletions include IGF2. A male patient was born with hypotonia, facial dysmorphisms and hypoglycemia suggestive of Beckwith-Wiedemann syndrome. Using methylation-specific (MS)-MLPA (Multiplex ligation-dependent probe amplification) we have identified a maternally inherited large deletion of the ICR1 region in a patient and his mother. The deletion results in a variable clinical expression with a classical BWS in the mother and a more severe presentation of BWS in her son. By genome-wide SNP array analysis the deletion was found to span ~100 kb genomic DNA including the ICR1DMR, H19, two adjacent non-imprinted genes and two of three predicted enhancer elements downstream to H19. Methylation analysis by deep bisulfite next generation sequencing revealed hypermethylation of the maternal allele at the IGF2 locus in both, mother and child, although IGF2 is not affected by the deletion. We here report on a novel large familial deletion of the ICR1 region in a BWS family. Due to the deletion of the ICR1-DMR CTCF binding cannot take place and the residual enhancer elements have access to the IGF2 promoters. The aberrant methylation (hypermethylation) of the maternal IGF2

Circumpolar assessment of rhizosphere priming shows limited increase in carbon loss estimates for permafrost soils but large regional variability

Science.gov (United States)

Wild, B.; Keuper, F.; Kummu, M.; Beer, C.; Blume-Werry, G.; Fontaine, S.; Gavazov, K.; Gentsch, N.; Guggenberger, G.; Hugelius, G.; Jalava, M.; Koven, C.; Krab, E. J.; Kuhry, P.; Monteux, S.; Richter, A.; Shazhad, T.; Dorrepaal, E.

2017-12-01

Predictions of soil organic carbon (SOC) losses in the northern circumpolar permafrost area converge around 15% (± 3% standard error) of the initial C pool by 2100 under the RCP 8.5 warming scenario. Yet, none of these estimates consider plant-soil interactions such as the rhizosphere priming effect (RPE). While laboratory experiments have shown that the input of plant-derived compounds can stimulate SOC losses by up to 1200%, the magnitude of RPE in natural ecosystems is unknown and no methods for upscaling exist so far. We here present the first spatial and depth explicit RPE model that allows estimates of RPE on a large scale (PrimeSCale). We combine available spatial data (SOC, C/N, GPP, ALT and ecosystem type) and new ecological insights to assess the importance of the RPE at the circumpolar scale. We use a positive saturating relationship between the RPE and belowground C allocation and two ALT-dependent rooting-depth distribution functions (for tundra and boreal forest) to proportionally assign belowground C allocation and RPE to individual soil depth increments. The model permits to take into account reasonable limiting factors on additional SOC losses by RPE including interactions between spatial and/or depth variation in GPP, plant root density, SOC stocks and ALT. We estimate potential RPE-induced SOC losses at 9.7 Pg C (5 - 95% CI: 1.5 - 23.2 Pg C) by 2100 (RCP 8.5). This corresponds to an increase of the current permafrost SOC-loss estimate from 15% of the initial C pool to about 16%. If we apply an additional molar C/N threshold of 20 to account for microbial C limitation as a requirement for the RPE, SOC losses by RPE are further reduced to 6.5 Pg C (5 - 95% CI: 1.0 - 16.8 Pg C) by 2100 (RCP 8.5). Although our results show that current estimates of permafrost soil C losses are robust without taking into account the RPE, our model also highlights high-RPE risk in Siberian lowland areas and Alaska north of the Brooks Range. The small overall impact of

Nanoscale control of Ag nanostructures for plasmonic fluorescence enhancement of near-infrared dyes

KAUST Repository

Xie, Fang

2013-05-23

Potential utilization of proteins for early detection and diagnosis of various diseases has drawn considerable interest in the development of protein-based detection techniques. Metal induced fluorescence enhancement offers the possibility of increasing the sensitivity of protein detection in clinical applications. We report the use of tunable plasmonic silver nanostructures for the fluorescence enhancement of a near-infrared (NIR) dye (Alexa Fluor 790). Extensive fluorescence enhancement of ∼2 orders of magnitude is obtained by the nanoscale control of the Ag nanostructure dimensions and interparticle distance. These Ag nanostructures also enhanced fluorescence from a dye with very high quantum yield (7.8 fold for Alexa Fluor 488, quantum efficiency (Qy) = 0.92). A combination of greatly enhanced excitation and an increased radiative decay rate, leading to an associated enhancement of the quantum efficiency leads to the large enhancement. These results show the potential of Ag nanostructures as metal induced fluorescence enhancement (MIFE) substrates for dyes in the NIR "biological window" as well as the visible region. Ag nanostructured arrays fabricated by colloidal lithography thus show great potential for NIR dye-based biosensing applications. [Figure not available: see fulltext.] © 2013 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

Factors affecting the performance of large-aperture microphone arrays

Science.gov (United States)

Silverman, Harvey F.; Patterson, William R.; Sachar, Joshua

2002-05-01

Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m×8 m×3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment.

Facilitating Cohort Discovery by Enhancing Ontology Exploration, Query Management and Query Sharing for Large Clinical Data Repositories

Science.gov (United States)

Tao, Shiqiang; Cui, Licong; Wu, Xi; Zhang, Guo-Qiang

2017-01-01

To help researchers better access clinical data, we developed a prototype query engine called DataSphere for exploring large-scale integrated clinical data repositories. DataSphere expedites data importing using a NoSQL data management system and dynamically renders its user interface for concept-based querying tasks. DataSphere provides an interactive query-building interface together with query translation and optimization strategies, which enable users to build and execute queries effectively and efficiently. We successfully loaded a dataset of one million patients for University of Kentucky (UK) Healthcare into DataSphere with more than 300 million clinical data records. We evaluated DataSphere by comparing it with an instance of i2b2 deployed at UK Healthcare, demonstrating that DataSphere provides enhanced user experience for both query building and execution. PMID:29854239

Facilitating Cohort Discovery by Enhancing Ontology Exploration, Query Management and Query Sharing for Large Clinical Data Repositories.

Science.gov (United States)

Tao, Shiqiang; Cui, Licong; Wu, Xi; Zhang, Guo-Qiang

2017-01-01

To help researchers better access clinical data, we developed a prototype query engine called DataSphere for exploring large-scale integrated clinical data repositories. DataSphere expedites data importing using a NoSQL data management system and dynamically renders its user interface for concept-based querying tasks. DataSphere provides an interactive query-building interface together with query translation and optimization strategies, which enable users to build and execute queries effectively and efficiently. We successfully loaded a dataset of one million patients for University of Kentucky (UK) Healthcare into DataSphere with more than 300 million clinical data records. We evaluated DataSphere by comparing it with an instance of i2b2 deployed at UK Healthcare, demonstrating that DataSphere provides enhanced user experience for both query building and execution.

Large Scale Plasmonic nanoCones array For Spectroscopy Detection

KAUST Repository

Das, Gobind

2015-09-24

Advanced optical materials or interfaces are gaining attention for diagnostic applications. However, the achievement of large device interface as well as facile surface functionalization largely impairs their wide use. The present work is aimed to address different innovative aspects related to the fabrication of large area 3D plasmonic arrays, their direct and easy functionalization with capture elements and their spectroscopic verifications through enhanced Raman and enhanced fluorescence techniques. In detail we have investigated the effect of Au-based nanoCones array, fabricated by means of direct nanoimprint technique over large area (mm2), on protein capturing and on the enhancement in optical signal. A selective functionalization of gold surfaces was proposed by using a peptide (AuPi3) previously selected by phage display. In this regard, two different sequences, labeled with fluorescein and biotin, were chemisorbed on metallic surfaces. The presence of Au nanoCones array consents an enhancement in electric field on the apex of cone, enabling the detection of molecules. We have witnessed around 12-fold increase in fluorescence intensity and SERS enhancement factor around 1.75 ×105 with respect to the flat gold surface. Furthermore, a sharp decrease in fluorescence lifetime over nanoCones confirms the increase in radiative emission (i.e. an increase in photonics density at the apex of cones).

Large Scale Plasmonic nanoCones array For Spectroscopy Detection

KAUST Repository

Das, Gobind; Battista, Edmondo; Manzo, Gianluigi; Causa, Filippo; Netti, Paolo; Di Fabrizio, Enzo M.

2015-01-01

Advanced optical materials or interfaces are gaining attention for diagnostic applications. However, the achievement of large device interface as well as facile surface functionalization largely impairs their wide use. The present work is aimed to address different innovative aspects related to the fabrication of large area 3D plasmonic arrays, their direct and easy functionalization with capture elements and their spectroscopic verifications through enhanced Raman and enhanced fluorescence techniques. In detail we have investigated the effect of Au-based nanoCones array, fabricated by means of direct nanoimprint technique over large area (mm2), on protein capturing and on the enhancement in optical signal. A selective functionalization of gold surfaces was proposed by using a peptide (AuPi3) previously selected by phage display. In this regard, two different sequences, labeled with fluorescein and biotin, were chemisorbed on metallic surfaces. The presence of Au nanoCones array consents an enhancement in electric field on the apex of cone, enabling the detection of molecules. We have witnessed around 12-fold increase in fluorescence intensity and SERS enhancement factor around 1.75 ×105 with respect to the flat gold surface. Furthermore, a sharp decrease in fluorescence lifetime over nanoCones confirms the increase in radiative emission (i.e. an increase in photonics density at the apex of cones).

Enhancement of natural radiation and population exposures due to the activity of large steelworks

Energy Technology Data Exchange (ETDEWEB)

Niewiadomski, T; Godek, J; Jasinska, M; Wasiolek, P [Institute of Nuclear Physics, Krakow (Poland)

1984-09-01

Radionuclide releases and resulting population exposures from large industrial plants have recently become a subject of some public concern. Methods for assessing these effects were developed and, as an example, a complex of large steelworks located in the vicinity of the city of Krakow was investigated. The following critical pathways were considered: atmospheric release, and use of fly ash for production of building materials. For assessing annual average radionuclide concentrations in air and in soil around the works, a computer program was developed while other mathematical methods were applied to the assessment of maximum individual effective dose equivalent commitments (EDEC) due to inhalation, ingestion, and external gamma radiation. In order to acquire data for calculations many samples of raw materials, coal, ash, and dust were analysed as to their radionuclide concentration. The total individual EDEC at the place of maximum immission was estimated to be about 100 ..mu..Sv a/sup -1/ (i.e., about 6% of the natural exposure in this region), this being mainly due to ingestion (ca. 65 ..mu..Sv a/sup -1/) and to gamma radiation (ca. 30 ..mu..Sv a/sup -1/). The enhancement of dose rates over the ponds and of radioactivity concentration of liquid discharges from the ponds was found to be negligible. Dose rates in houses built entirely of fly ash were estimated to be higher than those in red-brick houses by not more than 0.2 ..mu..Sv a/sup -1/. The collective EDEC from the operational discharge of the steelworks is less than 11 man Sv a/sup -1/ and that of use of fly-ash prefabricated elements will be in the future less than 45 man Sv a/sup -1/.

Explaining Large-N Cooperation: Generalized Social Trust and the Social Exchange Heuristic

DEFF Research Database (Denmark)

Sønderskov, Kim Mannemar

2011-01-01

This article presents a new argument that links generalized social trust and collective action in situations with a large number of actors, who do not have specific information on each other. Generalized social trust enhances large-N cooperation through the social exchange heuristic, which...... stimulate conditional cooperation in social dilemmas. Using data from a survey in four countries and recycling behavior as an indicator of collective action, this explanation is tested with individual level data. While the relationship between generalized social trust and large-N collective action is often...... hypothesized, there is scant micro level evidence as it has mainly been tested at the macro level. The results show that people holding generalized social trust cooperate more readily in large-N dilemmas, and that they most likely do so because of the social exchange heuristic....

Some connections between importance sampling and enhanced sampling methods in molecular dynamics.

Science.gov (United States)

Lie, H C; Quer, J

2017-11-21

In molecular dynamics, enhanced sampling methods enable the collection of better statistics of rare events from a reference or target distribution. We show that a large class of these methods is based on the idea of importance sampling from mathematical statistics. We illustrate this connection by comparing the Hartmann-Schütte method for rare event simulation (J. Stat. Mech. Theor. Exp. 2012, P11004) and the Valsson-Parrinello method of variationally enhanced sampling [Phys. Rev. Lett. 113, 090601 (2014)]. We use this connection in order to discuss how recent results from the Monte Carlo methods literature can guide the development of enhanced sampling methods.

Gold nanorods and nanospheroids for enhancing spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Mohammadi, A [Department of Physics, Persian Gulf University, 75196 Bushehr (Iran, Islamic Republic of); Sandoghdar, V; Agio, M [Laboratory of Physical Chemistry, ETH Zurich, 8093 Zurich (Switzerland)], E-mail: mario.agio@phys.chem.ethz.ch

2008-10-15

We compute the radiative decay rate and the quantum efficiency for an emitter coupled to gold nanorods and nanospheroids using the body-of-revolution finite-difference time-domain method. We study these quantities as a function of the nanoparticle aspect ratio and volume, showing that large enhancements can be achieved with realistic parameters. Moreover, we find that nanospheroids exhibit better performances than nanorods for applications in the visible and near-infrared spectral range.

Gold nanorods and nanospheroids for enhancing spontaneous emission

International Nuclear Information System (INIS)

Mohammadi, A; Sandoghdar, V; Agio, M

2008-01-01

We compute the radiative decay rate and the quantum efficiency for an emitter coupled to gold nanorods and nanospheroids using the body-of-revolution finite-difference time-domain method. We study these quantities as a function of the nanoparticle aspect ratio and volume, showing that large enhancements can be achieved with realistic parameters. Moreover, we find that nanospheroids exhibit better performances than nanorods for applications in the visible and near-infrared spectral range.

2'-OMe-phosphorodithioate-modified siRNAs show increased loading into the RISC complex and enhanced anti-tumour activity.

Science.gov (United States)

Wu, Sherry Y; Yang, Xianbin; Gharpure, Kshipra M; Hatakeyama, Hiroto; Egli, Martin; McGuire, Michael H; Nagaraja, Archana S; Miyake, Takahito M; Rupaimoole, Rajesha; Pecot, Chad V; Taylor, Morgan; Pradeep, Sunila; Sierant, Malgorzata; Rodriguez-Aguayo, Cristian; Choi, Hyun J; Previs, Rebecca A; Armaiz-Pena, Guillermo N; Huang, Li; Martinez, Carlos; Hassell, Tom; Ivan, Cristina; Sehgal, Vasudha; Singhania, Richa; Han, Hee-Dong; Su, Chang; Kim, Ji Hoon; Dalton, Heather J; Kovvali, Chandra; Keyomarsi, Khandan; McMillan, Nigel A J; Overwijk, Willem W; Liu, Jinsong; Lee, Ju-Seog; Baggerly, Keith A; Lopez-Berestein, Gabriel; Ram, Prahlad T; Nawrot, Barbara; Sood, Anil K

2014-03-12

Improving small interfering RNA (siRNA) efficacy in target cell populations remains a challenge to its clinical implementation. Here, we report a chemical modification, consisting of phosphorodithioate (PS2) and 2'-O-Methyl (2'-OMe) MePS2 on one nucleotide that significantly enhances potency and resistance to degradation for various siRNAs. We find enhanced potency stems from an unforeseen increase in siRNA loading to the RNA-induced silencing complex, likely due to the unique interaction mediated by 2'-OMe and PS2. We demonstrate the therapeutic utility of MePS2 siRNAs in chemoresistant ovarian cancer mouse models via targeting GRAM domain containing 1B (GRAMD1B), a protein involved in chemoresistance. GRAMD1B silencing is achieved in tumours following MePS2-modified siRNA treatment, leading to a synergistic anti-tumour effect in combination with paclitaxel. Given the previously limited success in enhancing siRNA potency with chemically modified siRNAs, our findings represent an important advance in siRNA design with the potential for application in numerous cancer types.

Explaining Large-N Cooperation: Generalized Social Trust and the Social Exchange Heuristic

DEFF Research Database (Denmark)

Sønderskov, Kim Mannemar

This paper argues that generalized social trust enhances collective action in situations with a large number of actors, who do not have specific information on each other. This effect comes about through the social exchange heuristic, which stimulate conditional cooperation in social dilemmas....... This paper tests this explanation in an individual level test. While the relationship between generalized social trust and large-N collective action is often hypothesized, there is scant micro level evidence as it has mainly been tested at the macro level. Using recycling behavior as an indicator...... of collective action, the paper shows that people holding generalized social trust cooperate more readily in large-N dilemmas. These results are based on a unique survey of respondents in four countries....

Large-D gravity and low-D strings.

Science.gov (United States)

Emparan, Roberto; Grumiller, Daniel; Tanabe, Kentaro

2013-06-21

We show that in the limit of a large number of dimensions a wide class of nonextremal neutral black holes has a universal near-horizon limit. The limiting geometry is the two-dimensional black hole of string theory with a two-dimensional target space. Its conformal symmetry explains the properties of massless scalars found recently in the large-D limit. For black branes with string charges, the near-horizon geometry is that of the three-dimensional black strings of Horne and Horowitz. The analogies between the α' expansion in string theory and the large-D expansion in gravity suggest a possible effective string description of the large-D limit of black holes. We comment on applications to several subjects, in particular to the problem of critical collapse.

Mice expressing a "hyper-sensitive" form of the CB1 cannabinoid receptor (CB1 show modestly enhanced alcohol preference and consumption.

Directory of Open Access Journals (Sweden)

David J Marcus

Full Text Available We recently characterized S426A/S430A mutant mice expressing a desensitization-resistant form of the CB1 receptor. These mice display an enhanced response to endocannabinoids and ∆9-THC. In this study, S426A/S430A mutants were used as a novel model to test whether ethanol consumption, morphine dependence, and reward for these drugs are potentiated in mice with a "hyper-sensitive" form of CB1. Using an unlimited-access, two-bottle choice, voluntary drinking paradigm, S426A/S430A mutants exhibit modestly increased intake and preference for low (6% but not higher concentrations of ethanol. S426A/S430A mutants and wild-type mice show similar taste preference for sucrose and quinine, exhibit normal sensitivity to the hypothermic and ataxic effects of ethanol, and have normal blood ethanol concentrations following administration of ethanol. S426A/S430A mutants develop robust conditioned place preference for ethanol (2 g/kg, morphine (10 mg/kg, and cocaine (10 mg/kg, demonstrating that drug reward is not changed in S426A/S430A mutants. Precipitated morphine withdrawal is also unchanged in opioid-dependent S426A/S430A mutant mice. Although ethanol consumption is modestly changed by enhanced CB1 signaling, reward, tolerance, and acute sensitivity to ethanol and morphine are normal in this model.

On the chemical enhancement in SERS

Science.gov (United States)

Jensen, Lasse

2012-12-01

In Surface-enhanced Raman scattering (SERS), the Raman signal of a molecule adsorbed on a metal surface is enhanced by many orders of magnitude. This provides a "finger-print" of molecules which can be used in ultrasensitive sensing devises. Here we present a time-dependent density functional theory (TDDFT) study of the molecule-surface chemical coupling in SERS. A systematic study of the chemical enhancement (CHEM) of meta-and para-substituted pyridines interacting with a small silver cluster (Ag20) is presented. We find that the magnitude of chemical enhancement is governed to a large extent by the energy difference between the highest occupied energy level (HOMO) of the metal and the lowest unoccupied energy level (LUMO) of the molecule. A two-state approximation shows that the enhancement scales roughly as (ωX/ω¯e)4, where accent="true">ω¯e is an average excitation energy between the HOMO of the metal and the LUMO of the molecule and wX the HOMO-LUMO gap of the free molecule. Furthermore, we demonstrate that it is possible to control the CHEM enhancement by switching a dithienylethene photoswitch from its closed form to its open form. The open form of the photoswitch is found to be the strongest Raman scatterer when adsorbed on the surface whereas the opposite is found for the free molecule. This trend is explained using the simple two-state approximation.

Magnetosheath dynamic pressure enhancements: occurrence and typical properties

Directory of Open Access Journals (Sweden)

M. O. Archer

2013-02-01

Full Text Available The first comprehensive statistical study of large-amplitude (> 100% transient enhancements of the magnetosheath dynamic pressure reveals events of up to ~ 15 times the ambient dynamic pressure with durations up to 3 min and an average duration of around 30 s, predominantly downstream of the quasi-parallel shock. The dynamic pressure transients are most often dominated by velocity increases along with a small fractional increase in the density, though the velocity is generally only deflected by a few degrees. Superposed wavelet transforms of the magnetic field show that, whilst most enhancements exhibit changes in the magnetosheath magnetic field, the majority are not associated with changes in the Interplanetary Magnetic Field (IMF. However, there is a minority of enhancements that do appear to be associated with solar wind discontinuities which cannot be explained simply by random events. In general, it is found that during periods of magnetosheath dynamic pressure enhancements the IMF is steadier than usual. This suggests that a stable foreshock and hence foreshock structures or processes may be important in the generation of the majority of magnetosheath dynamic pressure enhancements.

Ring enhancement in recurrent gliomas

International Nuclear Information System (INIS)

Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

1981-01-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas. (author)

Ring enhancement in recurrent gliomas

Energy Technology Data Exchange (ETDEWEB)

Ogashiwa, M; Takeuchi, K; Akai, K [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

1981-08-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas.

Natural Deposition Strategy for Interfacial, Self-Assembled, Large-Scale, Densely Packed, Monolayer Film with Ligand-Exchanged Gold Nanorods for In Situ Surface-Enhanced Raman Scattering Drug Detection.

Science.gov (United States)

Mao, Mei; Zhou, Binbin; Tang, Xianghu; Chen, Cheng; Ge, Meihong; Li, Pan; Huang, Xingjiu; Yang, Liangbao; Liu, Jinhuai

2018-03-15

Liquid interfacial self-assembly of metal nanoparticles holds great promise for its various applications, such as in tunable optical devices, plasmonics, sensors, and catalysis. However, the construction of large-area, ordered, anisotropic, nanoparticle monolayers and the acquisition of self-assembled interface films are still significant challenges. Herein, a rapid, validated method to fabricate large-scale, close-packed nanomaterials at the cyclohexane/water interface, in which hydrophilic cetyltrimethylammonium bromide coated nanoparticles and gold nanorods (AuNRs) self-assemble into densely packed 2D arrays by regulating the surface ligand and suitable inducer, is reported. Decorating AuNRs with polyvinylpyrrolidone not only extensively decreases the charge of AuNRs, but also diminishes repulsive forces. More importantly, a general, facile, novel technique to transfer an interfacial monolayer through a designed in situ reaction cell linked to a microfluidic chip is revealed. The self-assembled nanofilm can then automatically settle on the substrate and be directly detected in the reaction cell in situ by means of a portable Raman spectrometer. Moreover, a close-packed monolayer of self-assembled AuNRs provides massive, efficient hotspots to create great surface-enhanced Raman scattering (SERS) enhancement, which provides high sensitivity and reproducibility as the SERS-active substrate. Furthermore, this strategy was exploited to detect drug molecules in human urine for cyclohexane-extracted targets acting as the oil phase to form an oil/water interface. A portable Raman spectrometer was employed to detect methamphetamine down to 100 ppb levels in human urine, exhibiting excellent practicability. As a universal platform, handy tool, and fast pretreatment method with a good capability for drug detection in biological systems, this technique shows great promise for rapid, credible, and on-spot drug detection. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A facile method to prepare "green" nano-phosphors with a large Stokes-shift and solid-state enhanced photophysical properties based on surface-modified gold nanoclusters.

Science.gov (United States)

Cheng, C H; Huang, H Y; Talite, M J; Chou, W C; Yeh, J M; Yuan, C T

2017-12-15

Colloidal nano-materials, such as quantum dots (QDs) have been applied to light-conversion nano-phosphors due to their unique tunable emission. However, most of the QDs involve toxic elements and are synthesized in a hazardous solvent. In addition, conventional QD nano-phosphors with a small Stokes shift suffered from reabsorption losses and aggregation-induced quenching in the solid state. Here, we demonstrate a facile, matrix-free method to prepare eco-friendly nano-phosphors with a large Stokes shift based on aqueous thiolate-stabilized gold nanoclusters (GSH-AuNCs) with simple surface modifications. Our method is just to drop GSH-AuNCs solution on the aluminum foil and then surface-modified AuNCs (Al-GSH-AuNCs) can be spontaneously precipitated out of the aqueous solution. Compared with pristine GSH-AuNCs in solution, the Al-GSH-AuNCs exhibit enhanced solid-state PL quantum yields, lengthened PL lifetime, and spectral blue shift, which can be attributed to the aggregation-induced emission enhancement facilitated by surface modifications. Such surface-treatment induced aggregation of AuNCs can restrict the surface-ligand motion, leading to the enhancement of PL properties in the solid state. In addition, the Al-GSH-AuNCs nano-phosphors with a large Stokes shift can mitigate the aggregation-induced PL quenching and reabsorption losses, which would be potential candidates for "green" nano-phosphors. Copyright © 2017 Elsevier Inc. All rights reserved.

Anomalous nuclear enhancement of inclusive spectra at large transverse momentum

International Nuclear Information System (INIS)

Krzywicki, Andre.

1976-01-01

A parton model interpretation of the anomalous nuclear enhancement of inclusive spectra, observed by Cronin et al is proposed. It seems that the picture representing a nucleus as a collection of quasi-free nucleons in slow relative motion is incorrect when the nucleus is probed during a very short time. This conjecture rests on an extension to nuclei of the Kuti and Weisskopf parton model. A list of observable predictions concerning both hadronic and leptonic interactions with nuclei is given [fr

Large plasma density enhancements occurring in the northern polar region during the 6 April 2000 superstorm

Science.gov (United States)

Horvath, Ildiko; Lovell, Brian C.

2014-06-01

We focus on the ionospheric response of northern high-latitude region to the 6 April 2000 superstorm and aim to investigate how the storm-enhanced density (SED) plume plasma became distributed in the regions of auroral zone and polar cap plus to study the resultant ionospheric features and their development. Multi-instrument observational results combined with model-generated, two-cell convection maps permitted identifying the high-density plasma's origin and the underlying plasma transportation processes. Results show the plasma density feature of polar cap enhancement (PCE; 600 × 103 i+/cm3) appearing for 7 h during the main phase and characterized by increases reaching up to 6 times of the quiet time values. Meanwhile, strong westward convections ( 17,500 m/s) created low plasma densities in a wider region of the dusk cell. Oppositely, small ( 750 m/s) but rigorous westward drifts drove the SED plume plasma through the auroral zone, wherein plasma densities doubled. As the SED plume plasma traveled along the convection streamlines and entered the polar cap, a continuous enhancement of the tongue of ionization (TOI) developed under steady convection conditions. However, convection changes caused slow convections and flow stagnations and thus segmented the TOI feature by locally depleting the plasma in the affected regions of the auroral zone and polar cap. From the strong correspondence of polar cap potential drop and subauroral polarization stream (SAPS), we conclude that the SAPS E-field strength remained strong, and under its prolonged influence, the SED plume provided a continuous supply of downward flowing high-density plasma for the development and maintenance of PCEs.

Critical current enhancement by Lorentz force reduction in superconductor-ferromagnet nanocomposites

International Nuclear Information System (INIS)

Blamire, M G; Dinner, R B; Wimbush, S C; MacManus-Driscoll, J L

2009-01-01

Ferromagnetic pinning centres in superconductors form much deeper potential wells than equivalent insulating or metallic non-superconducting inclusions. However, the resultant pinning forces arising from magnetic inclusions are low because the magnetic interaction takes place over the length scale of the magnetic penetration depth which is large in technological superconductors. Nonetheless, we show that a magnetic inclusion can also reduce the Lorentz force on a vortex, yielding a substantially enhanced critical current density for a given pinning force. We calculate this enhancement for a single vortex pinned by a paramagnetic cylinder as well as a vortex lattice interacting with magnetic inclusions, and find that the inclusion of ferromagnetic particles or rods offers a practical means of enhancing the critical currents in oxide high temperature superconductors.

Plasmon-enhanced optically stimulated luminescence

International Nuclear Information System (INIS)

Guidelli, E. J.; Baffa, O.; Ramos, A. P.

2015-10-01

Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

Plasmon-enhanced optically stimulated luminescence

Energy Technology Data Exchange (ETDEWEB)

Guidelli, E. J.; Baffa, O. [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Ramos, A. P., E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Quimica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

2015-10-15

Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

The effect of an enhanced employee assistance program (EAP) intervention on EAP utilization.

Science.gov (United States)

Zarkin, G A; Bray, J W; Karuntzos, G T; Demiralp, B

2001-05-01

An enhanced employee assistance program (EAP) intervention was developed that delivers comprehensive EAP outreach services to all employees who may have alcohol-related and other workplace problems; standard EAP materials traditionally targeted at white men were enhanced to include women and minorities. This study evaluates whether the enhanced EAP intervention increased EAP utilization. The enhanced EAP intervention was developed at a large community-based not-for-profit EAP located in Rockford, Illinois. Two primary worksites and 16 other newly contracted worksites received the enhanced EAP intervention and served as intervention sites; the 107 other worksites serviced by the EAP were used as comparison sites. We used time series data from 1991 to 1998 and included repeated measures on each firm's quarterly EAP utilization. The enhanced EAP intervention increased the mean number of women and minority cases per worksite by 58%, white male cases by 45% and total EAP cases by 53%. This study shows that, for a modest cost, the enhanced EAP intervention successfully increased utilization of EAP by all employees, especially utilization by women and minority employees. It also shows that traditional EAP services and outreach materials can be made more appealing to women and minorities without adversely affecting their utilization by white men.

Distributed learning enhances relational memory consolidation.

Science.gov (United States)

Litman, Leib; Davachi, Lila

2008-09-01

It has long been known that distributed learning (DL) provides a mnemonic advantage over massed learning (ML). However, the underlying mechanisms that drive this robust mnemonic effect remain largely unknown. In two experiments, we show that DL across a 24 hr interval does not enhance immediate memory performance but instead slows the rate of forgetting relative to ML. Furthermore, we demonstrate that this savings in forgetting is specific to relational, but not item, memory. In the context of extant theories and knowledge of memory consolidation, these results suggest that an important mechanism underlying the mnemonic benefit of DL is enhanced memory consolidation. We speculate that synaptic strengthening mechanisms supporting long-term memory consolidation may be differentially mediated by the spacing of memory reactivation. These findings have broad implications for the scientific study of episodic memory consolidation and, more generally, for educational curriculum development and policy.

Manifesting enhanced cancellations in supergravity: integrands versus integrals

Energy Technology Data Exchange (ETDEWEB)

Bern, Zvi; Enciso, Michael; Parra-Martinez, Julio; Zeng, Mao [Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy,University of California at Los Angeles,Los Angeles, CA 90095 (United States)

2017-05-25

Examples of ‘enhanced ultraviolet cancellations’ with no known standard-symmetry explanation have been found in a variety of supergravity theories. By examining one- and two-loop examples in four- and five-dimensional half-maximal supergravity, we argue that enhanced cancellations in general cannot be exhibited prior to integration. In light of this, we explore reorganizations of integrands into parts that are manifestly finite and parts that have poor power counting but integrate to zero due to integral identities. At two loops we find that in the large loop-momentum limit the required integral identities follow from Lorentz and SL(2) relabeling symmetry. We carry out a nontrivial check at four loops showing that the identities generated in this way are a complete set. We propose that at L loops the combination of Lorentz and SL(L) symmetry is sufficient for displaying enhanced cancellations when they happen, whenever the theory is known to be ultraviolet finite up to (L−1) loops.

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Xu Huixiong; Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu; Lu Mingde

2010-01-01

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

Energy Technology Data Exchange (ETDEWEB)

Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

2010-08-15

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

RGB Color Cube-Based Histogram Specification for Hue-Preserving Color Image Enhancement

Directory of Open Access Journals (Sweden)

Kohei Inoue

2017-07-01

Full Text Available A large number of color image enhancement methods are based on the methods for grayscale image enhancement in which the main interest is contrast enhancement. However, since colors usually have three attributes, including hue, saturation and intensity of more than only one attribute of grayscale values, the naive application of the methods for grayscale images to color images often results in unsatisfactory consequences. Conventional hue-preserving color image enhancement methods utilize histogram equalization (HE for enhancing the contrast. However, they cannot always enhance the saturation simultaneously. In this paper, we propose a histogram specification (HS method for enhancing the saturation in hue-preserving color image enhancement. The proposed method computes the target histogram for HS on the basis of the geometry of RGB (rad, green and blue color space, whose shape is a cube with a unit side length. Therefore, the proposed method includes no parameters to be set by users. Experimental results show that the proposed method achieves higher color saturation than recent parameter-free methods for hue-preserving color image enhancement. As a result, the proposed method can be used for an alternative method of HE in hue-preserving color image enhancement.

Fast and accurate solution for the SCUC problem in large-scale power systems using adapted binary programming and enhanced dual neural network

International Nuclear Information System (INIS)

Shafie-khah, M.; Moghaddam, M.P.; Sheikh-El-Eslami, M.K.; Catalão, J.P.S.

2014-01-01

Highlights: • A novel hybrid method based on decomposition of SCUC into QP and BP problems is proposed. • An adapted binary programming and an enhanced dual neural network model are applied. • The proposed EDNN is exactly convergent to the global optimal solution of QP. • An AC power flow procedure is developed for including contingency/security issues. • It is suited for large-scale systems, providing both accurate and fast solutions. - Abstract: This paper presents a novel hybrid method for solving the security constrained unit commitment (SCUC) problem. The proposed formulation requires much less computation time in comparison with other methods while assuring the accuracy of the results. Furthermore, the framework provided here allows including an accurate description of warmth-dependent startup costs, valve point effects, multiple fuel costs, forbidden zones of operation, and AC load flow bounds. To solve the nonconvex problem, an adapted binary programming method and enhanced dual neural network model are utilized as optimization tools, and a procedure for AC power flow modeling is developed for including contingency/security issues, as new contributions to earlier studies. Unlike classical SCUC methods, the proposed method allows to simultaneously solve the unit commitment problem and comply with the network limits. In addition to conventional test systems, a real-world large-scale power system with 493 units has been used to fully validate the effectiveness of the novel hybrid method proposed

Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

2017-01-01

In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

Biomass saccharification is largely enhanced by altering wall polymer features and reducing silicon accumulation in rice cultivars harvested from nitrogen fertilizer supply.

Science.gov (United States)

Zahoor; Sun, Dan; Li, Ying; Wang, Jing; Tu, Yuanyuan; Wang, Yanting; Hu, Zhen; Zhou, Shiguang; Wang, Lingqiang; Xie, Guosheng; Huang, Jianliang; Alam, Aftab; Peng, Liangcai

2017-11-01

In this study, two rice cultivars were collected from experimental fields with seven nitrogen fertilizer treatments. All biomass samples contained significantly increased cellulose contents and reduced silica levels, with variable amounts of hemicellulose and lignin from different nitrogen treatments. Under chemical (NaOH, CaO, H 2 SO 4 ) and physical (hot water) pretreatments, biomass samples exhibited much enhanced hexoses yields from enzymatic hydrolysis, with high bioethanol production from yeast fermentation. Notably, both degree of polymerization (DP) of cellulose and xylose/arabinose (Xyl/Ara) ratio of hemicellulose were reduced in biomass residues, whereas other wall polymer features (cellulose crystallinity and monolignol proportion) were variable. Integrative analysis indicated that cellulose DP, hemicellulosic Xyl/Ara and silica are the major factors that significantly affect cellulose crystallinity and biomass saccharification. Hence, this study has demonstrated that nitrogen fertilizer supply could largely enhance biomass saccharification in rice cultivars, mainly by reducing cellulose DP, hemicellulosic Xyl/Ara and silica in cell walls. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low-temperature thermoelectric power factor enhancement by controlling nanoparticle size distribution.

Science.gov (United States)

Zebarjadi, Mona; Esfarjani, Keivan; Bian, Zhixi; Shakouri, Ali

2011-01-12

Coherent potential approximation is used to study the effect of adding doped spherical nanoparticles inside a host matrix on the thermoelectric properties. This takes into account electron multiple scatterings that are important in samples with relatively high volume fraction of nanoparticles (>1%). We show that with large fraction of uniform small size nanoparticles (∼1 nm), the power factor can be enhanced significantly. The improvement could be large (up to 450% for GaAs) especially at low temperatures when the mobility is limited by impurity or nanoparticle scattering. The advantage of doping via embedded nanoparticles compared to the conventional shallow impurities is quantified. At the optimum thermoelectric power factor, the electrical conductivity of the nanoparticle-doped material is larger than that of impurity-doped one at the studied temperature range (50-500 K) whereas the Seebeck coefficient of the nanoparticle doped material is enhanced only at low temperatures (∼50 K).

Dynamic investigation of nutrient consumption and injection strategy in microbial enhanced oil recovery (MEOR) by means of large-scale experiments.

Science.gov (United States)

Song, Zhiyong; Zhu, Weiyao; Sun, Gangzheng; Blanckaert, Koen

2015-08-01

Microbial enhanced oil recovery (MEOR) depends on the in situ microbial activity to release trapped oil in reservoirs. In practice, undesired consumption is a universal phenomenon but cannot be observed effectively in small-scale physical simulations due to the scale effect. The present paper investigates the dynamics of oil recovery, biomass and nutrient consumption in a series of flooding experiments in a dedicated large-scale sand-pack column. First, control experiments of nutrient transportation with and without microbial consumption were conducted, which characterized the nutrient loss during transportation. Then, a standard microbial flooding experiment was performed recovering additional oil (4.9 % Original Oil in Place, OOIP), during which microbial activity mostly occurred upstream, where oil saturation declined earlier and steeper than downstream in the column. Subsequently, more oil remained downstream due to nutrient shortage. Finally, further research was conducted to enhance the ultimate recovery by optimizing the injection strategy. An extra 3.5 % OOIP was recovered when the nutrients were injected in the middle of the column, and another additional 11.9 % OOIP were recovered by altering the timing of nutrient injection.

Maternal Obesity Induces Sustained Inflammation in Both Fetal and Offspring Large Intestine of Sheep

Science.gov (United States)

Yan, Xu; Huang, Yan; Wang, Hui; Du, Min; Hess, Bret W.; Ford, Stephen P.; Nathanielsz, Peter W.; Zhu, Mei-Jun

2010-01-01

Background Both maternal obesity and inflammatory bowel diseases (IBDs) are increasing. It was hypothesized that maternal obesity induces an inflammatory response in the fetal large intestine, predisposing offspring to IBDs. Methods Nonpregnant ewes were assigned to a control (Con, 100% of National Research Council [NRC] recommendations) or obesogenic (OB, 150% of NRC) diet from 60 days before conception. The large intestine was sampled from fetuses at 135 days (term 150 days) after conception and from offspring lambs at 22.5 ± 0.5 months of age. Results Maternal obesity enhanced mRNA expression tumor necrosis factor (TNF)α, interleukin (IL)1α, IL1β, IL6, IL8, and monocyte/macrophage chemotactic protein-1 (MCP1), as well as macrophage markers, CD11b, CD14, and CD68 in fetal gut. mRNA expression of Toll-like receptor (TLR) 2 and TLR4 was increased in OB versus Con fetuses; correspondingly, inflammatory NF-κB and JNK signaling pathways were also upregulated. Both mRNA expression and protein content of transforming growth factor (TGF) β was increased. The IL-17A mRNA expression and protein content was higher in OB compared to Con samples, which was associated with fibrosis in the large intestine of OB fetuses. Similar inflammatory responses and enhanced fibrosis were detected in OB compared to Con offspring. Conclusions Maternal obesity induced inflammation and enhanced expression of proinflammatory cytokines in fetal and offspring large intestine, which correlated with increased TGFβ and IL17 expression. These data show that maternal obesity may predispose offspring gut to IBDs. PMID:21674707

Seasonally asymmetric enhancement of northern vegetation productivity

Science.gov (United States)

Park, T.; Myneni, R.

2017-12-01

Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

A large-scale superhydrophobic surface-enhanced Raman scattering (SERS) platform fabricated via capillary force lithography and assembly of Ag nanocubes for ultratrace molecular sensing.

Science.gov (United States)

Tan, Joel Ming Rui; Ruan, Justina Jiexin; Lee, Hiang Kwee; Phang, In Yee; Ling, Xing Yi

2014-12-28

An analytical platform with an ultratrace detection limit in the atto-molar (aM) concentration range is vital for forensic, industrial and environmental sectors that handle scarce/highly toxic samples. Superhydrophobic surface-enhanced Raman scattering (SERS) platforms serve as ideal platforms to enhance detection sensitivity by reducing the random spreading of aqueous solution. However, the fabrication of superhydrophobic SERS platforms is generally limited due to the use of sophisticated and expensive protocols and/or suffers structural and signal inconsistency. Herein, we demonstrate a high-throughput fabrication of a stable and uniform superhydrophobic SERS platform for ultratrace molecular sensing. Large-area box-like micropatterns of the polymeric surface are first fabricated using capillary force lithography (CFL). Subsequently, plasmonic properties are incorporated into the patterned surfaces by decorating with Ag nanocubes using the Langmuir-Schaefer technique. To create a stable superhydrophobic SERS platform, an additional 25 nm Ag film is coated over the Ag nanocube-decorated patterned template followed by chemical functionalization with perfluorodecanethiol. Our resulting superhydrophobic SERS platform demonstrates excellent water-repellency with a static contact angle of 165° ± 9° and a consequent analyte concentration factor of 59-fold, as compared to its hydrophilic counterpart. By combining the analyte concentration effect of superhydrophobic surfaces with the intense electromagnetic "hot spots" of Ag nanocubes, our superhydrophobic SERS platform achieves an ultra-low detection limit of 10(-17) M (10 aM) for rhodamine 6G using just 4 μL of analyte solutions, corresponding to an analytical SERS enhancement factor of 10(13). Our fabrication protocol demonstrates a simple, cost- and time-effective approach for the large-scale fabrication of a superhydrophobic SERS platform for ultratrace molecular detection.

SUSY Higgs at the LHC large stop mixing effects and associated production

CERN Document Server

Bélanger, G; Sridhar, K

2000-01-01

We revisit the effect of the large stop mixing on the decay and production of the lightest SUSY Higgs at the LHC. We stress that whenever the inclusive 2-photon signature is substantially reduced, associated production, $Wh$ and $t\\bar t h$, with the subsequent decay of the Higgs into photons is enhanced and becomes an even more important discovery channel. We also point out that these reductions in the inclusive channel do not occur for the smallest Higgs mass where the significance is known to be lowest. We show that in such scenarios the Higgs can be produced in the decay of the heaviest stop. For not too heavy masses of the pseudo-scalar Higgs where the inclusive channel is even further reduced, we show that large stop mixing also allows the production of the pseudo-scalar Higgs through stop decays. These large mixing scenarios therefore offer much better prospects than previously thought. As a by-product we have recalculated stop1-stop1-h production at the LHC and give a first evaluation of stop1-stop1-Z...

Observation of largely enhanced hardness in nanomultilayers of the Ag-Nb system with positive enthalpy of formation

International Nuclear Information System (INIS)

Lai, W. S.; Yang, M. J.

2007-01-01

Ag/Nb nanomultilayers with different modulation wavelengths Λ were prepared on silicon wafers by electron beam evaporation. Nanoindenter measurements show that with decreasing Λ of the multilayers, the nanohardness increases up to ∼80% for Λ=4 nm, whereas the modulus is almost unchanged. This unusual behavior originates from a unique microstructure where amorphous Ag-Nb alloys form at the interfaces and grain boundaries of silver nanoparticles, as observed by cross-section high resolution transmission electron microscopy. The amorphous phases favor hardness enhancement by preventing dislocation emission and movement, whereas they have a negative contribution to the modulus because of their free volume

Large sensitivity enhancement in semiconducting organic field effect transistor sensors through incorporation of ultra-fine platinum nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zheng, Haisheng; Ramalingam, Balavinayagam; Korampally, Venumadhav; Gangopadhyay, Shubhra, E-mail: gangopadhyays@missouri.edu [Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65201 (United States)

2013-11-04

We report remarkable improvement in sensitivity of pentacene-based field effect transistor devices towards trace nitro-aromatic explosive vapors through the incorporation of high density, sub-2 nm platinum nanoparticles (NPs) within these structures. Exploiting the unique electronic properties of these NPs, we have demonstrated a detection limit of 56.6 parts per billion of 2,4-dinitrotoluene (DNT) vapor while control samples without any embedded NPs showed no observable sensitivity to DNT vapor. We attribute this remarkable enhancement in sensitivity to the ability of these NPs to function as discrete nodes, participating in the charge transfer with adsorbed nitro-aromatic molecules.

Disentangling the Impact of Control-Enhancing Mechanisms on Firm Performance

DEFF Research Database (Denmark)

Zattoni, Alessandro; Pedersen, Torben

2011-01-01

shareholders to expropriate minority shareholders. The aim of this article is to contribute to the current debate investigating the implications of these control-enhancing mechanisms on firm performance. To reach this purpose, we collected ownership data on the (100) largest listed companies per capitalization......Governance scholars and investors traditionally advocate against the use of control enhancing mechanisms, i.e. mechanisms aimed at separating voting and cash flow rights. These mechanisms may, in fact, determine a deviation from the proportionality principle and may encourage large and controlling...... in five European countries (i.e. France, Germany, Italy, Spain, and the UK). Then we tested the consequences of control-enhancing mechanisms for firm performance using 2SLS regression models. Our results show that (i) mechanisms that lock-in control do have a direct and negative impact on firm performance...

PIXE analysis showed that the preirradiation enhanced recovery of bone marrow elements after challenging irradiation in C57BL/6N Mice

International Nuclear Information System (INIS)

Matsuda, Y.; Yonezawa, M.; Nishiyama, F.

2000-01-01

Priming X-irradiation with 0.3-0.5 Gy induces radio-resistance in C57BL/6 strain of mice 2 weeks afterward. Elements in the bone marrow, sampled 11 days after challenging exposure to 5.0 Gy, were determined by PIXE. The challenging irradiation decreased Mg, P, S, K, Ca and Zn as well as dried bone marrow weight. The pre-irradiation enhanced recovery of these levels, indicating stimulated recovery of the metabolism int he tissue. Fe in both control (without pre-irradiation) and experimental groups increased to about twice the original value, showing elevated hemoglobin synthesis after challenging exposure. In previous studies we have reported that recovery of peripheral blood cell counts after sub-lethal irradiation was enhanced by the pre-irradiation. Further, study on accumulation of p53 and Bax proteins, which lead to apoptotic cell death, revealed that the pre-irradiation significantly suppressed accumulation of these proteins in the spleen after challenging irradiation with 3 Gy. These results and our present study suggest that the pre-irradiation decreased the spleen cell death, and favored re-growth of the spleen cells, resulting in stimulated recovery of metabolism for hematopoiesis in the bone marrow as well as in the spleen after challenging high dose irradiation. Stimulated recovery of Mg, P, S, K, Ca and Zn levels might indicate the importance of these elements in hematopoiesis. (author)

Mice expressing a “hyper-sensitive” form of the CB1 cannabinoid receptor (CB1) show modestly enhanced alcohol preference and consumption

Science.gov (United States)

Gonek, Maciej; Zee, Michael L.; Farnsworth, Jill C.; Amin, Randa A.; Andrews, Mary-Jeanette; Davis, Brian J.; Mackie, Ken; Morgan, Daniel J.

2017-01-01

We recently characterized S426A/S430A mutant mice expressing a desensitization-resistant form of the CB1 receptor. These mice display an enhanced response to endocannabinoids and ∆9-THC. In this study, S426A/S430A mutants were used as a novel model to test whether ethanol consumption, morphine dependence, and reward for these drugs are potentiated in mice with a “hyper-sensitive” form of CB1. Using an unlimited-access, two-bottle choice, voluntary drinking paradigm, S426A/S430A mutants exhibit modestly increased intake and preference for low (6%) but not higher concentrations of ethanol. S426A/S430A mutants and wild-type mice show similar taste preference for sucrose and quinine, exhibit normal sensitivity to the hypothermic and ataxic effects of ethanol, and have normal blood ethanol concentrations following administration of ethanol. S426A/S430A mutants develop robust conditioned place preference for ethanol (2 g/kg), morphine (10 mg/kg), and cocaine (10 mg/kg), demonstrating that drug reward is not changed in S426A/S430A mutants. Precipitated morphine withdrawal is also unchanged in opioid-dependent S426A/S430A mutant mice. Although ethanol consumption is modestly changed by enhanced CB1 signaling, reward, tolerance, and acute sensitivity to ethanol and morphine are normal in this model. PMID:28426670

MRI enhancement of the facial nerve with Gd-DTPA, 1

International Nuclear Information System (INIS)

Yanagida, Masahiro

1993-01-01

Although there have recently been numerous reports of enhanced MRI in patients with facial palsy, the mechanism of enhancement remains largely unknown. In the present study, animal models with experimentally induced facial paralysis were prepared, and the vascular permeabilities of normal and damaged facial nerves were assessed using Evans blue albumin (EBA) as a tracer. The Gd-DTPA contents in normal and compressively damaged facial nerves were also investigated. In the normal intratemporal facial nerve, EBA remained in the vessels, and did not leak into the endoneurium. In contrast, vascular permeability was very high in the epineurium and the geniculate ganglion which showed leakage of large amounts of EBA from vessels. At the site of compression in the damaged nerve, EBA leakage was also seen in the endoneurism, indicating accentuated vascular permeability. This accentuation of vascular permeability shifted toward the distal side. However, no EBA leakage was seen on the side proximal to the site of compression. Significantly higher Gd-DTPA contents were obtained in the facial nerve on the paralytic side than in that on the normal side (p<0.001). As for differences between the distal and proximal sides, the distal side had a significantly higher Gd-DTPA content (p<0.01). Assessment of vascular permeability with EBA revealed accentuated vascular permeability on the side distal to the site of compression. These results showed the presence of a blood nerve barrier (BNB) in the facial nerve. Furthermore, the present findings suggest that the enhancement of the facial nerve on the affected side is caused by BNB destruction due to nerve damage and subsequent Gd-DTPA leakage from the vessels. Furthermore, it is suggested that the facial nerve enhancement appears to occur mainly on the distal side of the damaged portion of the nerve. (author)

In planta Transformed Cumin (Cuminum cyminum L.) Plants, Overexpressing the SbNHX1 Gene Showed Enhanced Salt Endurance.

Science.gov (United States)

Pandey, Sonika; Patel, Manish Kumar; Mishra, Avinash; Jha, Bhavanath

2016-01-01

Cumin is an annual, herbaceous, medicinal, aromatic, spice glycophyte that contains diverse applications as a food and flavoring additive, and therapeutic agents. An efficient, less time consuming, Agrobacterium-mediated, a tissue culture-independent in planta genetic transformation method was established for the first time using cumin seeds. The SbNHX1 gene, cloned from an extreme halophyte Salicornia brachiata was transformed in cumin using optimized in planta transformation method. The SbNHX1 gene encodes a vacuolar Na+/H+ antiporter and is involved in the compartmentalization of excess Na+ ions into the vacuole and maintenance of ion homeostasis Transgenic cumin plants were confirmed by PCR using gene (SbNHX1, uidA and hptII) specific primers. The single gene integration event and overexpression of the gene were confirmed by Southern hybridization and competitive RT-PCR, respectively. Transgenic lines L3 and L13 showed high expression of the SbNHX1 gene compared to L6 whereas moderate expression was detected in L5 and L10 transgenic lines. Transgenic lines (L3, L5, L10 and L13), overexpressing the SbNHX1 gene, showed higher photosynthetic pigments (chlorophyll a, b and carotenoid), and lower electrolytic leakage, lipid peroxidation (MDA content) and proline content as compared to wild type plants under salinity stress. Though transgenic lines were also affected by salinity stress but performed better compared to WT plants. The ectopic expression of the SbNHX1 gene confirmed enhanced salinity stress tolerance in cumin as compared to wild type plants under stress condition. The present study is the first report of engineering salt tolerance in cumin, so far and the plant may be utilized for the cultivation in saline areas.

In planta Transformed Cumin (Cuminum cyminum L. Plants, Overexpressing the SbNHX1 Gene Showed Enhanced Salt Endurance.

Directory of Open Access Journals (Sweden)

Sonika Pandey

Full Text Available Cumin is an annual, herbaceous, medicinal, aromatic, spice glycophyte that contains diverse applications as a food and flavoring additive, and therapeutic agents. An efficient, less time consuming, Agrobacterium-mediated, a tissue culture-independent in planta genetic transformation method was established for the first time using cumin seeds. The SbNHX1 gene, cloned from an extreme halophyte Salicornia brachiata was transformed in cumin using optimized in planta transformation method. The SbNHX1 gene encodes a vacuolar Na+/H+ antiporter and is involved in the compartmentalization of excess Na+ ions into the vacuole and maintenance of ion homeostasis Transgenic cumin plants were confirmed by PCR using gene (SbNHX1, uidA and hptII specific primers. The single gene integration event and overexpression of the gene were confirmed by Southern hybridization and competitive RT-PCR, respectively. Transgenic lines L3 and L13 showed high expression of the SbNHX1 gene compared to L6 whereas moderate expression was detected in L5 and L10 transgenic lines. Transgenic lines (L3, L5, L10 and L13, overexpressing the SbNHX1 gene, showed higher photosynthetic pigments (chlorophyll a, b and carotenoid, and lower electrolytic leakage, lipid peroxidation (MDA content and proline content as compared to wild type plants under salinity stress. Though transgenic lines were also affected by salinity stress but performed better compared to WT plants. The ectopic expression of the SbNHX1 gene confirmed enhanced salinity stress tolerance in cumin as compared to wild type plants under stress condition. The present study is the first report of engineering salt tolerance in cumin, so far and the plant may be utilized for the cultivation in saline areas.

Enhanced superconductivity of fullerenes

Energy Technology Data Exchange (ETDEWEB)

Washington, II, Aaron L.; Teprovich, Joseph A.; Zidan, Ragaiy

2017-06-20

Methods for enhancing characteristics of superconductive fullerenes and devices incorporating the fullerenes are disclosed. Enhancements can include increase in the critical transition temperature at a constant magnetic field; the existence of a superconducting hysteresis over a changing magnetic field; a decrease in the stabilizing magnetic field required for the onset of superconductivity; and/or an increase in the stability of superconductivity over a large magnetic field. The enhancements can be brought about by transmitting electromagnetic radiation to the superconductive fullerene such that the electromagnetic radiation impinges on the fullerene with an energy that is greater than the band gap of the fullerene.

Large-scale self-assembled zirconium phosphate smectic layers via a simple spray-coating process

Science.gov (United States)

Wong, Minhao; Ishige, Ryohei; White, Kevin L.; Li, Peng; Kim, Daehak; Krishnamoorti, Ramanan; Gunther, Robert; Higuchi, Takeshi; Jinnai, Hiroshi; Takahara, Atsushi; Nishimura, Riichi; Sue, Hung-Jue

2014-04-01

The large-scale assembly of asymmetric colloidal particles is used in creating high-performance fibres. A similar concept is extended to the manufacturing of thin films of self-assembled two-dimensional crystal-type materials with enhanced and tunable properties. Here we present a spray-coating method to manufacture thin, flexible and transparent epoxy films containing zirconium phosphate nanoplatelets self-assembled into a lamellar arrangement aligned parallel to the substrate. The self-assembled mesophase of zirconium phosphate nanoplatelets is stabilized by epoxy pre-polymer and exhibits rheology favourable towards large-scale manufacturing. The thermally cured film forms a mechanically robust coating and shows excellent gas barrier properties at both low- and high humidity levels as a result of the highly aligned and overlapping arrangement of nanoplatelets. This work shows that the large-scale ordering of high aspect ratio nanoplatelets is easier to achieve than previously thought and may have implications in the technological applications for similar materials.

Hepatic enhancement on Gd-BOPTA-enhanced MR imaging: comparison between cirrhotic and normal livers

International Nuclear Information System (INIS)

Shin, Sang Soo; Jeong, Yong Yeon; Kang, Heoung Keun; Lim, Hyo Soon; Yoon, Woong; Seo, Jeong Jin; Park, Jin Gyoon

2004-01-01

To compare the enhancement features of hepatic parenchyma between cirrhotic and normal liver, using Gd-BOPTA-enhanced delayed MR imaging. The 60 patients (35 with cirrhotic and 25 with normal liver) included in our study underwent Gd-BOPTA-enhanced MR imaging using a 1.5T system with a phase-array multicoil. In all cases, T1-weighted in-phase and opposed-phase gradient-echo MR imaging was performed before and 60 minutes after intravenous administration of a bolus of Gd-BOPTA. All images were quantitatively analysed by comparing the signal-to-noise ratio (SNR) and signal enhancement (SE) of cirrhotic and normal liver before and after contrast enhancement, and in cirrhotic patients, SNR and SE were also compared in terms of the Child-Pugh classification. For qualitative analysis, the hepatic enhancement patterns of cirrhotic and normal liver were classified as homogeneous or heterogeneous according to the consensual findings of two radiologists. At contrast-enhanced imaging, both cirrhotic (p<0.001) and normal liver (p<0.001) showed substantially increased SNR relative to unenhanced images, and the SNR of cirrhotic liver was significantly lower than that of normal livers at both in-phase (p<0.001) and opposed-phase (p<0.001) imaging. The SE of cirrhotic liver was significantly lower than that of normal liver (in-phase:p=0.002; opposed phase:p=0.011). Both Child-Pugh class A (p<0.001) and B (p<0.001) cirrhotic liver showed a substantial increase in SNR at contrast-enhanced imaging relative to unenhanced imaging and the SNR of Child-Pugh class A was significantly higher than that of Child-Pugh class B at both in-phase (p<0.001) and opposed-phase (p=0.022) imaging. In addition, the SE of class A was significantly higher than that of class B at in-phase imaging (p=0.004). Cirrhotic liver showed heterogeneous enhancement in 20 of 35 patients (57%), whereas normal liver showed homogeneous enhancement in all patients. At Gd-BOPTA-enhanced delayed MR imaging, cirrhotic liver

Enhanced Nonadiabaticity in Vortex Cores due to the Emergent Hall Effect

KAUST Repository

Bisig, André

2017-01-04

We present a combined theoretical and experimental study, investigating the origin of the enhanced nonadiabaticity of magnetic vortex cores. Scanning transmission x-ray microscopy is used to image the vortex core gyration dynamically to measure the nonadiabaticity with high precision, including a high confidence upper bound. We show theoretically, that the large nonadiabaticity parameter observed experimentally can be explained by the presence of local spin currents arising from a texture induced emergent Hall effect. This study demonstrates that the magnetic damping α and nonadiabaticity parameter β are very sensitive to the topology of the magnetic textures, resulting in an enhanced ratio (β/α>1) in magnetic vortex cores or Skyrmions.

Enhanced Nonadiabaticity in Vortex Cores due to the Emergent Hall Effect

KAUST Repository

Bisig, André ; Akosa, Collins Ashu; Moon, Jung-Hwan; Rhensius, Jan; Moutafis, Christoforos; von Bieren, Arndt; Heidler, Jakoba; Kiliani, Gillian; Kammerer, Matthias; Curcic, Michael; Weigand, Markus; Tyliszczak, Tolek; Van Waeyenberge, Bartel; Stoll, Hermann; Schü tz, Gisela; Lee, Kyung-Jin; Manchon, Aurelien; Klä ui, Mathias

2017-01-01

We present a combined theoretical and experimental study, investigating the origin of the enhanced nonadiabaticity of magnetic vortex cores. Scanning transmission x-ray microscopy is used to image the vortex core gyration dynamically to measure the nonadiabaticity with high precision, including a high confidence upper bound. We show theoretically, that the large nonadiabaticity parameter observed experimentally can be explained by the presence of local spin currents arising from a texture induced emergent Hall effect. This study demonstrates that the magnetic damping α and nonadiabaticity parameter β are very sensitive to the topology of the magnetic textures, resulting in an enhanced ratio (β/α>1) in magnetic vortex cores or Skyrmions.

Transient Stability Enhancement in Power System Using Static VAR Compensator (SVC

Directory of Open Access Journals (Sweden)

Youssef MOULOUDI

2012-12-01

Full Text Available In this paper, an indirect adaptive fuzzy excitation and static VAR (unit of reactive power, volt-ampere reactive compensator (SVC controller is proposed to enhance transient stability for the power system, which based on input-output linearization technique. A three-bus system, which contains a generator and static VAR compensator (SVC, is considered in this paper, the SVC is located at the midpoint of the transmission lines. Simulation results show that the proposed controller compared with a controller based on tradition linearization technique can enhance the transient stability of the power system under a large sudden fault, which may occur nearly at the generator bus terminal.

Numerical Study of the Rib Arrangements for Enhancing Heat Transfer in a Two-pass Channel of Large Aspect Ratio

Energy Technology Data Exchange (ETDEWEB)

Han, Sol; Choi, Seok Min; Sohn, Ho-Seong; Cho, Hyung Hee [Yonsei Univ., Seoul (Korea, Republic of)

2017-03-15

The present study investigated the effect of the rib arrangement and a guide vane for enhancing internal cooling of the blade. Two types of rib arrangements were used in the first and second passage in parallel. Aspect ratio of the channel was 5 and a fixed Reynolds number based on hydraulic diameter was 10,000. The attack angle of rib was 60°, rib pitch-to-height ratio (p/e) was 10, and the rib height-to-hydraulic-diameter ratio (e/D{sub n}) was 0.075. The effect of an interaction between Dean vortices and the secondary vortices from the first passage was observed. Overall, the attack angle of rib in the first passage was dominant factor to heat transfer and flow patterns in turning region. Also, the channel with a guide vane showed enhanced heat transfer at the tip surface with reducing flow separation and recirculation.

Plasmonic resonance-enhanced local photothermal energy deposition by aluminum nanoparticles

International Nuclear Information System (INIS)

Chong Xinyuan; Jiang Naibo; Zhang Zhili; Roy, Sukesh; Gord, James R.

2013-01-01

Local energy deposition of aluminum nanoparticles (Al NPs) by localized surface plasmon resonance-enhanced photothermal effects is demonstrated. Low-power light stimuli are efficiently and locally concentrated to trigger the oxidation reactions of Al NPs because of the large ohmic absorption and high reactivity of the Al. Numerical simulations show that both ultraviolet and visible light are more efficient than infrared light for photothermal energy coupling. The natural oxidation layer of alumina is found to have minimum impact on the energy deposition because of its negligible dielectric losses. The near-field distributions of the electric field indicate that slight aggregation induces much higher local enhancement, especially at the interface region of multiple contacting nanoparticles.

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

Science.gov (United States)

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-05

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH 4 + strategy for ethylene and SO 2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO 2 from fruits. It was satisfied that trace ethylene and SO 2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO 2 during the entire LVCC sampling process were proved to be gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

Evidence of a Large Triggered Event in the Nepal Himalaya Following the Gorkha Earthquake: Implications Toward Enhanced Seismic Hazard

Science.gov (United States)

Mandal, Prantik

2018-03-01

A DC (double couple) constrained multiple point-source moment-tensor inversion is performed on the band-passed (0.008-0.10 Hz) displacement data of the 25 April (M w 7.8) 2015 Nepal mainshock, from 17 broadband stations in India. Our results reveal that the 25 April event (strike = 324°, dip = 14°, rake = 88°) ruptured the north-dipping main Himalayan thrust (MHT) at 16 km depth. We modeled the Coulomb failure stress changes (ΔCFS) produced by the slip on the fault plane of the 25 April Nepal mainshock. A strong correlation with occurrences of aftershocks and regions of increased positive ΔCFS is obtained below the aftershock zone of the 2015 Nepal mainshock. We notice that predicted ΔCFS at 16 km depth show a positive Coulomb stress of 0.06 MPa at the location of the 12 May 2015 event. These small modeled stress changes can lead to trigger events if the crust is already near to failure, but these small stresses can also advance the occurrence of future earthquakes. The main finding of our ΔCFS modeling implies that the 25 April event increased the Coulomb stress changes by 0.06 MPa at 16 km depth below the site of the 12 May event, and thus, this event can be termed as triggered. We propose that the seismic hazard in the Himalaya is not only caused by the mainshock slip on the MHT; rather, the occurrence of large triggered event on the MHT can also enhance our understanding of the seismic hazard in the Nepal Himalaya.

Endometrial Cancer Side-Population Cells Show Prominent Migration and Have a Potential to Differentiate into the Mesenchymal Cell Lineage

Science.gov (United States)

Kato, Kiyoko; Takao, Tomoka; Kuboyama, Ayumi; Tanaka, Yoshihiro; Ohgami, Tatsuhiro; Yamaguchi, Shinichiro; Adachi, Sawako; Yoneda, Tomoko; Ueoka, Yousuke; Kato, Keiji; Hayashi, Shinichi; Asanoma, Kazuo; Wake, Norio

2010-01-01

Cancer stem-like cell subpopulations, referred to as “side-population” (SP) cells, have been identified in several tumors based on their ability to efflux the fluorescent dye Hoechst 33342. Although SP cells have been identified in the normal human endometrium and endometrial cancer, little is known about their characteristics. In this study, we isolated and characterized the SP cells in human endometrial cancer cells and in rat endometrial cells expressing oncogenic human K-Ras protein. These SP cells showed i) reduction in the expression levels of differentiation markers; ii) long-term proliferative capacity of the cell cultures; iii) self-renewal capacity in vitro; iv) enhancement of migration, lamellipodia, and, uropodia formation; and v) enhanced tumorigenicity. In nude mice, SP cells formed large, invasive tumors, which were composed of both tumor cells and stromal-like cells with enriched extracellular matrix. The expression levels of vimentin, α-smooth muscle actin, and collagen III were enhanced in SP tumors compared with the levels in non-SP tumors. In addition, analysis of microdissected samples and fluorescence in situ hybridization of Hec1-SP-tumors showed that the stromal-like cells with enriched extracellular matrix contained human DNA, confirming that the stromal-like cells were derived from the inoculated cells. Moreober, in a Matrigel assay, SP cells differentiated into α-smooth muscle actin-expressing cells. These findings demonstrate that SP cells have cancer stem-like cell features, including the potential to differentiate into the mesenchymal cell lineage. PMID:20008133

Surface-Enhanced Raman Spectroscopy of Dye and Thiol Molecules Adsorbed on Triangular Silver Nanostructures: A Study of Near-Field Enhancement, Localization of Hot-Spots, and Passivation of Adsorbed Carbonaceous Species

Directory of Open Access Journals (Sweden)

Manuel R. Gonçalves

2012-01-01

Full Text Available Surface-enhanced Raman spectroscopy (SERS of thiols and dye molecules adsorbed on triangular silver nanostructures was investigated. The SERS hot-spots are localized at the edges and corners of the silver triangular particles. AFM and SEM measurements permit to observe many small clusters formed at the edges of triangular particles fabricated by nanosphere lithography. Finite-element calculations show that near-field enhancements can reach values of more than 200 at visible wavelengths, in the gaps between small spherical particles and large triangular particles, although for the later no plasmon resonance was found at the wavelengths investigated. The regions near the particles showing strong near-field enhancement are well correlated with spatial localization of SERS hot-spots done by confocal microscopy. Silver nanostructures fabricated by thermal evaporation present strong and fast fluctuating SERS activity, due to amorphous carbon contamination. Thiols and dye molecules seem to be able to passivate the undesired SERS activity on fresh evaporated silver.

Polymer as permeability modifier in porous media for enhanced oil recovery

Science.gov (United States)

Parsa, Shima; Weitz, David

2017-11-01

We use confocal microscopy to directly visualize the changes in morphology and mobilization of trapped oil ganglia within a 3D micromodel of porous media upon polymer flooding. Enhanced oil recovery is achieved in polymer flooding with large molecular weight at concentrations close or higher than a critical concentration of polymer. We also measure the fluctuations of the velocity of the displacing fluid and show that the velocities change upon polymer flooding in the whole medium. The changes in the fluid velocities are heterogeneous and vary in different pores, hence only providing enough pressure gradient across a few of the trapped oil ganglia and mobilize them. Our measurements show that polymer flooding is an effective method for enhancing oil recovery due to retention of polymer on the solid surfaces and changing the resistances of the available paths to water.

Reversal by EGTA of the enhanced secretory responsiveness of mast cells due to treatment with ouabain

DEFF Research Database (Denmark)

Johansen, Torben; Knudsen, T; Bertelsen, Niels Haldor

1990-01-01

The effect of EGTA on the enhancement by ouabain of compound 48/80-induced secretion from mast cells was compared with the effect on the Na(+)-K+ pump activity. The time-dependent secretory enhancement by ouabain was blocked by addition of EGTA to the cell suspension concomitantly with the addition...... of ouabain, and EGTA caused a large increase in the pump activity. Addition of 10 microM EGTA to ouabain-treated cells stopped but did not reverse the enhancement. The experiments show that the effect of ouabain was due to changes in a calcium pool utilized in compound 48/80-induced secretion following...

Spatial bandwidth enlargement and field enhancement of shear horizontal waves in finite graded piezoelectric layered media

International Nuclear Information System (INIS)

Xu, Yanlong

2015-01-01

Shear horizontal (SH) wave propagation in finite graded piezoelectric layered media is investigated by transfer matrix method. Different from the previous studies on SH wave propagation in completely periodic layered media, calculations on band structure and transmission in this paper show that the graded layered media possess very large band gaps. Harmonic wave simulation by finite element method (FEM) confirms that the reason of bandwidth enlargement is that waves within the band gap ranges are spatially enhanced and stopped by the corresponding graded units. The study suggests that the graded structure possesses the property of manipulating elastic waves spatially, which shows potential applications in strengthening energy trapping and harvesting. - Highlights: • Shear horizontal wave propagation in finite graded piezoelectric layered media is investigated by transfer matrix method. • Calculations on band structure and transmission show that the graded layered media possess very large band gaps. • Finite element method confirms that waves in band gaps are spatially enhanced and stopped by the graded units. • The study suggests that the graded structure possesses the property of manipulating elastic waves spatially

Enhanced room-temperature spin Seebeck effect in a YIG/C60/Pt layered heterostructure

Science.gov (United States)

Das, R.; Kalappattil, V.; Geng, R.; Luong, H.; Pham, M.; Nguyen, T.; Liu, Tao; Wu, Mingzhong; Phan, M. H.; Srikanth, H.

2018-05-01

We report on large enhancement of the longitudinal spin Seebeck effect (LSSE) in the Y3Fe5O12 (YIG)/Pt system at room temperature due to the addition of a thin layer of organic semiconductor (C60) in between the YIG and the Pt. LSSE measurements show that the LSSE voltage increases significantly, from the initial value of 150 nV for the YIG/Pt structure to 240 nV for the YIG/C60(5nm)/Pt structure. Radio-frequency transverse susceptibility experiments reveal a significant decrease in the surface perpendicular magnetic anisotropy (PMA) of the YIG film when C60 is deposited on it. These results suggest that the LSSE enhancement may be attributed to increased spin mixing conductance, the decreased PMA, and the large spin diffusion length of C60.

Analyzing Snowpack Metrics Over Large Spatial Extents Using Calibrated, Enhanced-Resolution Brightness Temperature Data and Long Short Term Memory Artificial Neural Networks

Science.gov (United States)

Norris, W.; J Q Farmer, C.

2017-12-01

Snow water equivalence (SWE) is a difficult metric to measure accurately over large spatial extents; snow-tell sites are too localized, and traditional remotely sensed brightness temperature data is at too coarse of a resolution to capture variation. The new Calibrated Enhanced-Resolution Brightness Temperature (CETB) data from the National Snow and Ice Data Center (NSIDC) offers remotely sensed brightness temperature data at an enhanced resolution of 3.125 km versus the original 25 km, which allows for large spatial extents to be analyzed with reduced uncertainty compared to the 25km product. While the 25km brightness temperature data has proved useful in past research — one group found decreasing trends in SWE outweighed increasing trends three to one in North America; other researchers used the data to incorporate winter conditions, like snow cover, into ecological zoning criterion — with the new 3.125 km data, it is possible to derive more accurate metrics for SWE, since we have far more spatial variability in measurements. Even with higher resolution data, using the 37 - 19 GHz frequencies to estimate SWE distorts the data during times of melt onset and accumulation onset. Past researchers employed statistical splines, while other successful attempts utilized non-parametric curve fitting to smooth out spikes distorting metrics. In this work, rather than using legacy curve fitting techniques, a Long Short Term Memory (LSTM) Artificial Neural Network (ANN) was trained to perform curve fitting on the data. LSTM ANN have shown great promise in modeling time series data, and with almost 40 years of data available — 14,235 days — there is plenty of training data for the ANN. LSTM's are ideal for this type of time series analysis because they allow important trends to persist for long periods of time, but ignore short term fluctuations; since LSTM's have poor mid- to short-term memory, they are ideal for smoothing out the large spikes generated in the melt

Threshold enhancement of diphoton resonances

CERN Document Server

Bharucha, Aoife; Goudelis, Andreas

2016-10-10

The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. The implications of such a threshold enhancement are discussed in two explicit scenarios: i) the Minimal Supersymmetric Standard Model in which the $A$ state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through...

Kaempferol enhances endothelium-dependent relaxation in the porcine coronary artery through activation of large-conductance Ca(2+) -activated K(+) channels.

Science.gov (United States)

Xu, Y C; Leung, S W S; Leung, G P H; Man, R Y K

2015-06-01

Kaempferol, a plant flavonoid present in normal human diet, can modulate vasomotor tone. The present study aimed to elucidate the signalling pathway through which this flavonoid enhanced relaxation of vascular smooth muscle. The effect of kaempferol on the relaxation of porcine coronary arteries to endothelium-dependent (bradykinin) and -independent (sodium nitroprusside) relaxing agents was studied in an in vitro organ chamber setup. The whole-cell patch-clamp technique was used to determine the effect of kaempferol on potassium channels in porcine coronary artery smooth muscle cells (PCASMCs). At a concentration without direct effect on vascular tone, kaempferol (3 × 10(-6) M) enhanced relaxations produced by bradykinin and sodium nitroprusside. The potentiation by kaempferol of the bradykinin-induced relaxation was not affected by N(ω)-nitro-L-arginine methyl ester, an inhibitor of NO synthase (10(-4) M) or TRAM-34 plus UCL 1684, inhibitors of intermediate- and small-conductance calcium-activated potassium channels, respectively (10(-6) M each), but was abolished by tetraethylammonium chloride, a non-selective inhibitor of calcium-activated potassium channels (10(-3) M), and iberiotoxin, a selective inhibitor of large-conductance calcium-activated potassium channel (KCa 1.1; 10(-7) M). Iberiotoxin also inhibited the potentiation by kaempferol of sodium nitroprusside-induced relaxations. Kaempferol stimulated an outward-rectifying current in PCASMCs, which was abolished by iberiotoxin. The present results suggest that, in smooth muscle cells of the porcine coronary artery, kaempferol enhanced relaxations caused by endothelium-derived and exogenous NO as well as those due to endothelium-dependent hyperpolarization. This vascular effect of kaempferol involved the activation of KCa 1.1 channels. © 2015 The British Pharmacological Society.

Transgenic alfalfa (Medicago sativa) with increased sucrose phosphate synthase activity shows enhanced growth when grown under N2-fixing conditions.

Science.gov (United States)

Gebril, Sayed; Seger, Mark; Villanueva, Fabiola Muro; Ortega, Jose Luis; Bagga, Suman; Sengupta-Gopalan, Champa

2015-10-01

Overexpression of SPS in alfalfa is accompanied by early flowering, increased plant growth and an increase in elemental N and protein content when grown under N2-fixing conditions. Sucrose phosphate synthase (SPS; EC 2.3.1.14) is the key enzyme in the synthesis of sucrose in plants. The outcome of overexpression of SPS in different plants using transgenic approaches has been quite varied, but the general consensus is that increased SPS activity is associated with the production of new sinks and increased sink strength. In legumes, the root nodule is a strong C sink and in this study our objective was to see how increasing SPS activity in a legume would affect nodule number and function. Here we have transformed alfalfa (Medicago sativa, cv. Regen SY), with a maize SPS gene driven by the constitutive CaMV35S promoter. Our results showed that overexpression of SPS in alfalfa, is accompanied by an increase in nodule number and mass and an overall increase in nitrogenase activity at the whole plant level. The nodules exhibited an increase in the level of key enzymes contributing to N assimilation including glutamine synthetase and asparagine synthetase. Moreover, the stems of the transformants showed higher level of the transport amino acids, Asx, indicating increased export of N from the nodules. The transformants exhibited a dramatic increase in growth both of the shoots and roots, and earlier flowering time, leading to increased yields. Moreover, the transformants showed an increase in elemental N and protein content. The overall conclusion is that increased SPS activity improves the N status and plant performance, suggesting that the availability of more C in the form of sucrose enhances N acquisition and assimilation in the nodules.

High-order-harmonic generation from H2+ molecular ions near plasmon-enhanced laser fields

Science.gov (United States)

Yavuz, I.; Tikman, Y.; Altun, Z.

2015-08-01

Simulations of plasmon-enhanced high-order-harmonic generation are performed for a H2+ molecular cation near the metallic nanostructures. We employ the numerical solution of the time-dependent Schrödinger equation in reduced coordinates. We assume that the main axis of H2+ is aligned perfectly with the polarization direction of the plasmon-enhanced field. We perform systematic calculations on plasmon-enhanced harmonic generation based on an infinite-mass approximation, i.e., pausing nuclear vibrations. Our simulations show that molecular high-order-harmonic generation from plasmon-enhanced laser fields is possible. We observe the dispersion of a plateau of harmonics when the laser field is plasmon enhanced. We find that the maximum kinetic energy of the returning electron follows 4 Up . We also find that when nuclear vibrations are enabled, the efficiency of the harmonics is greatly enhanced relative to that of static nuclei. However, the maximum kinetic energy 4 Up is largely maintained.

Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

Energy Technology Data Exchange (ETDEWEB)

Kim, Bohyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Ajou University School of Medicine, Department of Radiology, Suwon (Korea, Republic of); Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

2016-01-15

To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

International Nuclear Information System (INIS)

Kim, Bohyun; Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun

2016-01-01

To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

Evidence of universal inverse-third power law for the shielding-induced fractional decrease in apex field enhancement factor at large spacings: a response via accurate Laplace-type calculations

Science.gov (United States)

de Assis, Thiago A.; Dall’Agnol, Fernando F.

2018-05-01

Numerical simulations are important when assessing the many characteristics of field emission related phenomena. In small simulation domains, the electrostatic effect from the boundaries is known to influence the calculated apex field enhancement factor (FEF) of the emitter, but no established dependence has been reported at present. In this work, we report the dependence of the lateral size, L, and the height, H, of the simulation domain on the apex-FEF of a single conducting ellipsoidal emitter. Firstly, we analyze the error, ε, in the calculation of the apex-FEF as a function of H and L. Importantly, our results show that the effects of H and L on ε are scale invariant, allowing one to predict ε for ratios L/h and H/h, where h is the height of the emitter. Next, we analyze the fractional change of the apex-FEF, δ, from a single emitter, , and a pair, . We show that small relative errors in (i.e. ), due to the finite domain size, are sufficient to alter the functional dependence , where c is the distance from the emitters in the pair. We show that obeys a recently proposed power law decay (Forbes 2016 J. Appl. Phys. 120 054302), at sufficiently large distances in the limit of infinite domain size (, say), which is not observed when using a long time established exponential decay (Bonard et al 2001 Adv. Mater. 13 184) or a more sophisticated fitting formula proposed recently by Harris et al (2015 AIP Adv. 5 087182). We show that the inverse-third power law functional dependence is respected for various systems like infinity arrays and small clusters of emitters with different shapes. Thus, , with m  =  3, is suggested to be a universal signature of the charge-blunting effect in small clusters or arrays, at sufficient large distances between emitters with any shape. These results improve the physical understanding of the field electron emission theory to accurately characterize emitters in small clusters or arrays.

Observation of enhanced ozone in an electrically active storm over Socorro, NM: Implications for ozone production from corona discharges

Science.gov (United States)

Minschwaner, K.; Kalnajs, L. E.; Dubey, M. K.; Avallone, L. M.; Sawaengphokai, P. C.; Edens, H. E.; Winn, W. P.

2008-09-01

Enhancements in ozone were observed between about 3 and 10 km altitude within an electrically active storm in central New Mexico. Measurements from satellite sensors and ground-based radar show cloud top pressures between 300 and 150 mb in the vicinity of an ozonesonde launched from Socorro, NM, and heavy precipitation with radar reflectivities exceeding 50 dBZ. Data from a lightning mapping array and a surface electric field mill show a large amount of electrical activity within this thunderstorm. The observed ozone enhancements are large (50% above the mean) and could have resulted from a number of possible processes, including the advection of polluted air from the urban environments of El Paso and Juarez, photochemical production by lightning-generated NOx from aged thunderstorm outflow, downward mixing of stratospheric air, or local production from within the thunderstorm. We find that a large fraction of the ozone enhancement is consistent with local production from corona discharges, either from cloud particles or by corona associated with lightning. The implied global source of ozone from thunderstorm corona discharge is estimated to be 110 Tg O3 a-1 with a range between 40 and 180 Tg O3 a-1. This value is about 21% as large as the estimated ozone production rate from lightning NOx, and about 3% as large as the total chemical production rate of tropospheric ozone. Thus while the estimated corona-induced production of ozone may be significant on local scales, it is unlikely to be as important to the global ozone budget as other sources.

Dynamic placement of plasmonic hotspots for super-resolution surface-enhanced Raman scattering.

Science.gov (United States)

Ertsgaard, Christopher T; McKoskey, Rachel M; Rich, Isabel S; Lindquist, Nathan C

2014-10-28

In this paper, we demonstrate dynamic placement of locally enhanced plasmonic fields using holographic laser illumination of a silver nanohole array. To visualize these focused "hotspots", the silver surface was coated with various biological samples for surface-enhanced Raman spectroscopy (SERS) imaging. Due to the large field enhancements, blinking behavior of the SERS hotspots was observed and processed using a stochastic optical reconstruction microscopy algorithm enabling super-resolution localization of the hotspots to within 10 nm. These hotspots were then shifted across the surface in subwavelength (hotspots. Using this technique, we also show that such subwavelength shifting and localization of plasmonic hotspots has potential for imaging applications. Interestingly, illuminating the surface with randomly shifting SERS hotspots was sufficient to completely fill in a wide field of view for super-resolution chemical imaging.

A facile solvothermal synthesis of large-grain iron cubes and cuboids with enhanced performances

International Nuclear Information System (INIS)

Yang, Bai; Yang, Xueying; Li, Xiaopan; Cao, Ying; Yu, Ronghai

2016-01-01

The cubic and cuboid pure iron particles with particle size ranging from 500 nm to 2 μm have been fabricated using a solvothermal method in ethanol solution. The controlled morphology and size distribution can be easily tuned by adjusting the reaction temperatures. The morphologies of the as-synthesized iron particles can be transformed from cubes to cuboids with the reaction temperature increasing from 100 to 150 °C. Uniform particles with narrow size distribution and good dispersion can be obtained under 120 °C. These chemically synthesized Fe particles exhibit good air stability and very slight surface oxidation. High saturation magnetization of 208–211 A m 2 /kg and very low coercivity of 19–26 Oe can be achieved in these micron-level iron particles due to their high purity and small shape anisotropy. The relatively simple preparation process with low cost, good air stability and high saturation magnetization for these large-grain pure iron particles promise their great potential applications in complicated shape and miniaturized Fe-based composite magnetic components. - Highlights: • The micron-level cubic and cuboid pure iron particles have been prepared. • The morphologies of the large-grain iron particles can be tuned. • These iron particles show slight surface oxidation and good air stability. • These iron particles exhibit high saturation magnetization of 208–211 A m 2 kg −1 .

Interface enhancement of glass fiber reinforced vinyl ester composites with flame-synthesized carbon nanotubes and its enhancing mechanism.

Science.gov (United States)

Liao, Lingmin; Wang, Xiao; Fang, Pengfei; Liew, Kim Meow; Pan, Chunxu

2011-02-01

Interface enhancement with carbon nanotubes (CNTs) provides a promising approach for improving shock strength and toughness of glass fiber reinforced plastic (GFRP) composites. The effects of incorporating flame-synthesized CNTs (F-CNTs) into GFRP were studied, including on hand lay-up preparation, microstructural characterization, mechanical properties, fracture morphologies, and theoretical calculation. The experimental results showed that: (1) the impact strength of the GFRP modified by F-CNTs increased by more than 15% over that of the GFRP modified by CNTs from chemical vapor deposition; and (2) with the F-CNT enhancement, no interfacial debonding was observed at the interface between the fiber and resin matrix on the GFRP fracture surface, which indicated strong adhesive strength between them. The theoretical calculation revealed that the intrinsic characteristics of the F-CNTs, including lower crystallinity with a large number of defects and chemical functional groups on the surface, promoted their surface activity and dispersibility at the interface, which improved the interfacial bond strength of GFRP.

Microwave-assisted synthesis of NiS2 nanostructures for supercapacitors and cocatalytic enhancing photocatalytic H2 production

Science.gov (United States)

Pang, Huan; Wei, Chengzhen; Li, Xuexue; Li, Guochang; Ma, Yahui; Li, Sujuan; Chen, Jing; Zhang, Jiangshan

2014-01-01

Uniform NiS2 nanocubes are successfully synthesized with a microwave-assisted method. Interestingly, NiS2 nanocubes, nanospheres and nanoparticles are obtained by controlling microwave reaction time. NiS2 nanomaterials are primarily applied to supercapacitors and cocatalytic enhancing photocatalytic H2 production. Different morphologies of NiS2 nanostructures show different electrochemical and cocatalytic enhancing H2 production activities. Benefited novel nanostructures, NiS2 nanocube electrodes show a large specific capacitance (695 F g-1 at 1.25 A g-1) and excellent cycling performance (the retention 93.4% of initial specific capacitance after 3000 cycles). More importantly, NiS2 nanospheres show highly cocatalytic enhancing photocatalytic for H2 evolution, in which the photocatalytic H2 production is up to 3400 μmol during 12 hours under irradiation of visible light (λ>420 nm) with an average H2 production rate of 283 μmol h-1.

Implantation of autogenous meniscal fragments wrapped with a fascia sheath enhances fibrocartilage regeneration in vivo in a large harvest site defect.

Science.gov (United States)

Kobayashi, Yasukazu; Yasuda, Kazunori; Kondo, Eiji; Katsura, Taro; Tanabe, Yoshie; Kimura, Masashi; Tohyama, Harukazu

2010-04-01

Concerning meniscal tissue regeneration, many investigators have studied the development of a tissue-engineered meniscus. However, the utility still remains unknown. Implantation of autogenous meniscal fragments wrapped with a fascia sheath into the donor site meniscal defect may significantly enhance fibrocartilage regeneration in vivo in the defect. Controlled laboratory study. Seventy-five mature rabbits were used in this study. In each animal, an anterior one-third of the right medial meniscus was resected. Then, the animals were divided into the following 3 groups of 25 rabbits each: In group 1, no treatment was applied to the meniscal defect. In group 2, the defect was covered with a fascia sheath. In group 3, after the resected meniscus was fragmented into small pieces, the fragments were grafted into the defect. Then, the defect with the meniscal fragments was covered with a fascia sheath. In each group, 5 rabbits were used for histological evaluation at 3, 6, and 12 weeks after surgery, and 5 rabbits were used for biomechanical evaluation at 6 and 12 weeks after surgery. Histologically, large round cells in group 3 were scattered in the core portion of the meniscus-shaped tissue, and the matrix around these cells was positively stained by safranin O and toluisin blue at 12 weeks. The histological score of group 3 was significantly higher than that of group 1 and group 2. Biomechanically, the maximal load and stiffness of group 3 were significantly greater than those of groups 1 and 2. This study clearly demonstrated that implantation of autogenous meniscal fragments wrapped with a fascia sheath into the donor site meniscal defect significantly enhanced fibrocartilage regeneration in vivo in the defect at 12 weeks after implantation in the rabbit. This study proposed a novel strategy to treat a large defect after a meniscectomy.

Realistic-contact-induced enhancement of rectifying in carbon-nanotube/graphene-nanoribbon junctions

International Nuclear Information System (INIS)

Zhang, Xiang-Hua; Li, Xiao-Fei; Wang, Ling-Ling; Xu, Liang; Luo, Kai-Wu

2014-01-01

Carbon-nanotube/graphene-nanoribbon junctions were recently fabricated by the controllable etching of single-walled carbon-nanotubes [Wei et al., Nat. Commun. 4, 1374 (2013)] and their electronic transport properties were studied here. First principles results reveal that the transmission function of the junctions show a heavy dependence on the shape of contacts, but rectifying is an inherent property which is insensitive to the details of contacts. Interestingly, the rectifying ratio is largely enhanced in the junction with a realistic contact and the enhancement is insensitive to the details of contact structures. The stability of rectifying suggests a significant feasibility to manufacture realistic all-carbon rectifiers in nanoelectronics

Using the IGCRA (individual, group, classroom reflective action technique to enhance teaching and learning in large accountancy classes

Directory of Open Access Journals (Sweden)

Cristina Poyatos

2011-02-01

Full Text Available First year accounting has generally been perceived as one of the more challenging first year business courses for university students. Various Classroom Assessment Techniques (CATs have been proposed to attempt to enrich and enhance student learning, with these studies generally positioning students as learners alone. This paper uses an educational case study approach and examines the implementation of the IGCRA (individual, group, classroom reflective action technique, a Classroom Assessment Technique, on first year accounting students’ learning performance. Building on theoretical frameworks in the areas of cognitive learning, social development, and dialogical learning, the technique uses reports to promote reflection on both learning and teaching. IGCRA was found to promote feedback on the effectiveness of student, as well as teacher satisfaction. Moreover, the results indicated formative feedback can assist to improve the learning and learning environment for a large group of first year accounting students. Clear guidelines for its implementation are provided in the paper.

Pool Boiling Enhancement of R-123 Using Perforated Plates

Energy Technology Data Exchange (ETDEWEB)

Kim, Nae-Hyun [Incheon Nat’l Univ., Incheon(Korea, Republic of)

2016-05-15

In this study, we investigate the pool boiling enhancement caused by perforated plates on top of a smooth surface. We conduct tests using R-123 at atmospheric pressure. It was shown that perforated plates significantly enhanced the pool boiling of the smooth surface. The reason may be attributed to the increased bubble contact area between the plates. The results showed that the enhancement ratio was dependent on the heat flux. At high heat flux, the enhancement ratio increased as the porosity increased. However, at low heat flux, the enhancement ratio decreased as the porosity increased. For the present investigation, the optimum configuration had a pore diameter of 2.0 mm, pore pitch of 2.5 mm×5.0 mm or 5.0 mm×5.0 mm, and a gap width of 0.5 mm, which yielded heat-transfer coefficients that are close to those of GEWA-T. The optimum porosity for R-123 was significantly larger than that of water or ethanol. The reason for this may be the large liquid-to-vapor density ratio along with the small latent heat of vaporization of R-123. The perforated plates yielded smaller boiling hysteresis compared with that of the smooth surface.

Two-stage nuclear refrigeration with enhanced nuclear moments

International Nuclear Information System (INIS)

Hunik, R.

1979-01-01

Experiments are described in which an enhanced nuclear system is used as a precoolant for a nuclear demagnetisation stage. The results show the promising advantages of such a system in those circumstances for which a large cooling power is required at extremely low temperatures. A theoretical review of nuclear enhancement at the microscopic level and its macroscopic thermodynamical consequences is given. The experimental equipment for the implementation of the nuclear enhanced refrigeration method is described and the experiments on two-stage nuclear demagnetisation are discussed. With the nuclear enhanced system PrCu 6 the author could precool a nuclear stage of indium in a magnetic field of 6 T down to temperatures below 10 mK; this resulted in temperature below 1 mK after demagnetisation of the indium. It is demonstrated that the interaction energy between the nuclear moments in an enhanced nuclear system can exceed the nuclear dipolar interaction. Several experiments are described on pulsed nuclear magnetic resonance, as utilised for thermometry purposes. It is shown that platinum NMR-thermometry gives very satisfactory results around 1 mK. The results of experiments on nuclear orientation of radioactive nuclei, e.g. the brute force polarisation of 95 NbPt and 60 CoCu, are presented, some of which are of major importance for the thermometry in the milli-Kelvin region. (Auth.)

2’f-OMe-phosphorodithioate modified siRNAs show increased loading into the RISC complex and enhanced anti-tumour activity

Science.gov (United States)

Wu, Sherry Y.; Yang, Xianbin; Gharpure, Kshipra M.; Hatakeyama, Hiroto; Egli, Martin; McGuire, Michael H.; Nagaraja, Archana S.; Miyake, Takahito M.; Rupaimoole, Rajesha; Pecot, Chad V.; Taylor, Morgan; Pradeep, Sunila; Sierant, Malgorzata; Rodriguez-Aguayo, Cristian; Choi, Hyun J.; Previs, Rebecca A.; Armaiz-Pena, Guillermo N.; Huang, Li; Martinez, Carlos; Hassell, Tom; Ivan, Cristina; Sehgal, Vasudha; Singhania, Richa; Han, Hee-Dong; Su, Chang; Kim, Ji Hoon; Dalton, Heather J.; Kowali, Chandra; Keyomarsi, Khandan; McMillan, Nigel A.J.; Overwijk, Willem W.; Liu, Jinsong; Lee, Ju-Seog; Baggerly, Keith A.; Lopez-Berestein, Gabriel; Ram, Prahlad T.; Nawrot, Barbara; Sood, Anil K.

2014-01-01

Improving small interfering RNA (siRNA) efficacy in target cell populations remains a challenge to its clinical implementation. Here, we report a chemical modification, consisting of phosphorodithioate (PS2) and 2’-O-Methyl (2’-OMe) MePS2 on one nucleotide that significantly enhances potency and resistance to degradation for various siRNAs. We find enhanced potency stems from an unforeseen increase in siRNA loading to the RNA-induced silencing complex, likely due to the unique interaction mediated by 2’-OMe and PS2. We demonstrate the therapeutic utility of MePS2 siRNAs in chemoresistant ovarian cancer mouse models via targeting GRAM Domain Containing 1B (GRAMD1B), a protein involved in chemoresistance. GRAMD1B silencing is achieved in tumors following MePS2-modified siRNA treatment, leading to a synergistic anti-tumor effect in combination with paclitaxel. Given the previously limited success in enhancing siRNA potency with chemically modified siRNAs, our findings represent an important advance in siRNA design with the potential for application in numerous cancer types. PMID:24619206

High-Performance, Large Format Surfaces for Surface-Enhanced Raman Spectroscopy: Increasing the Accessibility of an Analytical Platform

Science.gov (United States)

Kanipe, Katherine Nicole

Although surface-enhanced Raman spectroscopy (SERS) is a spectroscopic technique with unusually high sensitivity and molecular specificity, few practical analytical applications have been implemented that take advantage of its power. Based on what is understood about SERS from the experimental and theoretical research of the past forty years, we developed a few well-defined design principles on the basis of which a reliable and reproducibly manufacturable SERS-active substrate could be fabricated that is highly enhancing, highly uniform, stable, and based on a broad range of metals so that various chemical processes could be probed. Finally, we restricted ourselves to using only readily scalable fabrication techniques. The resulting SERS-active device was a metal over silica, two-dimensional nano-grating that was shown to produce enhancements of ˜107 when compared to a smooth surface of the same metal. This SERS substrate also shows unprecedented signal uniformity over square centimeters, and is fabricated using commonly-available foundry-based approaches exclusively. Initially, we explored the properties of a gold-coated substrates in which a first-order grating resonance due to long-range symmetry is augmented by a local resonance due to the individual core-shell grating elements. The SERS properties of such grating systems were systematically studied as a function of various structural parameters such as the grating pitch, the inter-element gap and the thickness of the metal layer. The most enhancing substrates were found to have a grating parameter with a radiative, rather than evanescent, first-order resonance; a sufficiently small gap between nearest neighbor grating elements to produce near-field interactions; and a gold layer whose thickness was larger than the electronic mean-free-path of the conduction electrons, so as to ensure a high conductivity for the metal layer to sustain strong surface plasmons. We applied these same architectural principles to

Assessment of the MDNBR enhancement methodologies for the SMART control rods banks withdrawal event

International Nuclear Information System (INIS)

Yang, Soo Hyung; Chung, Young-Jong; Kim, Hee Cheol

2005-01-01

For an electricity generation and seawater desalination, a 330 MW System-integrated Modular Advanced ReacTor (SMART) was developed by KAERI. The safety level of the SMART is enhanced when compared to that of the typical commercial reactors, with the aid of an elimination of a large break loss of coolant accident by placing the major components of the primary system in a reactor vessel and the adoption of a new technology and a passive design concept into the safety system. However, the events related to reactivity and power distribution anomalies have been evaluated as vulnerable points when compared to the other initiating events in the SMART, since the reactivity worth of the control rods (CR) banks is quite large due to the boron free core concept. Especially, safety margins, i.e., minimum departure from nucleate boiling ratio (MDNBR), are significantly threatened during the CR banks withdrawal event. Therefore, MDNBR enhancement methodology for the CR banks withdrawal event should be considered to further enhance the safety level of the SMART design. Two methodologies have been suggested to enhance the MDNBR during the CR banks withdrawal event: the application of a DNBR trip function into a core protection system and a turbine trip delay methodology. Sensitivity studies are performed to evaluate the two MDNBR enhancement methodologies and show that the suggested methodologies could enhance the MDNBR during the CR banks withdrawal event of the SMART

Quantum mechanical limit to plasmonic enhancement as observed by surface-enhanced Raman scattering.

Science.gov (United States)

Zhu, Wenqi; Crozier, Kenneth B

2014-10-14

Plasmonic nanostructures enable light to be concentrated into nanoscale 'hotspots', wherein the intensity of light can be enhanced by orders of magnitude. This plasmonic enhancement significantly boosts the efficiency of nanoscale light-matter interactions, enabling unique linear and nonlinear optical applications. Large enhancements are often observed within narrow gaps or at sharp tips, as predicted by the classical electromagnetic theory. Only recently has it become appreciated that quantum mechanical effects could emerge as the feature size approaches atomic length-scale. Here we experimentally demonstrate, through observations of surface-enhanced Raman scattering, that the emergence of electron tunnelling at optical frequencies limits the maximum achievable plasmonic enhancement. Such quantum mechanical effects are revealed for metallic nanostructures with gap-widths in the single-digit angstrom range by correlating each structure with its optical properties. This work furthers our understanding of quantum mechanical effects in plasmonic systems and could enable future applications of quantum plasmonics.

Kaempferol enhances endothelium-dependent relaxation in the porcine coronary artery through activation of large-conductance a2+-activated K+ channels

Science.gov (United States)

Xu, Y C; Leung, S W S; Leung, G P H; Man, R Y K

2015-01-01

Background and Purpose Kaempferol, a plant flavonoid present in normal human diet, can modulate vasomotor tone. The present study aimed to elucidate the signalling pathway through which this flavonoid enhanced relaxation of vascular smooth muscle. Experimental Approach The effect of kaempferol on the relaxation of porcine coronary arteries to endothelium-dependent (bradykinin) and -independent (sodium nitroprusside) relaxing agents was studied in an in vitro organ chamber setup. The whole-cell patch-clamp technique was used to determine the effect of kaempferol on potassium channels in porcine coronary artery smooth muscle cells (PCASMCs). Key Results At a concentration without direct effect on vascular tone, kaempferol (3 × 10−6 M) enhanced relaxations produced by bradykinin and sodium nitroprusside. The potentiation by kaempferol of the bradykinin-induced relaxation was not affected by Nω-nitro-L-arginine methyl ester, an inhibitor of NO synthase (10−4 M) or TRAM-34 plus UCL 1684, inhibitors of intermediate- and small-conductance calcium-activated potassium channels, respectively (10−6 M each), but was abolished by tetraethylammonium chloride, a non-selective inhibitor of calcium-activated potassium channels (10−3 M), and iberiotoxin, a selective inhibitor of large-conductance calcium-activated potassium channel (KCa1.1; 10−7 M). Iberiotoxin also inhibited the potentiation by kaempferol of sodium nitroprusside-induced relaxations. Kaempferol stimulated an outward-rectifying current in PCASMCs, which was abolished by iberiotoxin. Conclusions and Implications The present results suggest that, in smooth muscle cells of the porcine coronary artery, kaempferol enhanced relaxations caused by endothelium-derived and exogenous NO as well as those due to endothelium-dependent hyperpolarization. This vascular effect of kaempferol involved the activation of KCa1.1 channels. PMID:25652142

Large area substrate for surface enhanced Raman spectroscopy (SERS) using glass-drawing technique

Science.gov (United States)

Ivanov, Ilia N; Simpson, John T

2012-06-26

A method of making a large area substrate comprises drawing a plurality of tubes to form a plurality of drawn tubes, and cutting the plurality of drawn tubes into cut drawn tubes. Each cut drawn tube has a first end and a second end along the longitudinal direction of the respective cut drawn tube. The cut drawn tubes collectively have a predetermined periodicity. The method of making a large area substrate also comprises forming a metal layer on the first ends of the cut drawn tubes to provide a large area substrate.

Microwave-assisted synthesis of NiS2 nanostructures for supercapacitors and cocatalytic enhancing photocatalytic H2 production

Science.gov (United States)

Pang, Huan; Wei, Chengzhen; Li, Xuexue; Li, Guochang; Ma, Yahui; Li, Sujuan; Chen, Jing; Zhang, Jiangshan

2014-01-01

Uniform NiS2 nanocubes are successfully synthesized with a microwave-assisted method. Interestingly, NiS2 nanocubes, nanospheres and nanoparticles are obtained by controlling microwave reaction time. NiS2 nanomaterials are primarily applied to supercapacitors and cocatalytic enhancing photocatalytic H2 production. Different morphologies of NiS2 nanostructures show different electrochemical and cocatalytic enhancing H2 production activities. Benefited novel nanostructures, NiS2 nanocube electrodes show a large specific capacitance (695 F g−1 at 1.25 A g−1) and excellent cycling performance (the retention 93.4% of initial specific capacitance after 3000 cycles). More importantly, NiS2 nanospheres show highly cocatalytic enhancing photocatalytic for H2 evolution, in which the photocatalytic H2 production is up to 3400 μmol during 12 hours under irradiation of visible light (λ>420 nm) with an average H2 production rate of 283 μmol h−1. PMID:24389929

Mathematical model for biomolecular quantification using large-area surface-enhanced Raman spectroscopy mapping

DEFF Research Database (Denmark)

Palla, Mirkó; Bosco, Filippo; Yang, Jaeyoung

2015-01-01

Surface-enhanced Raman spectroscopy (SERS) based on nanostructured platforms is a promising technique for quantitative and highly sensitive detection of biomolecules in the field of analytical biochemistry. Here, we report a mathematical model to predict experimental SERS signal (or hotspot) inte...

Bone marrow-derived mesenchymal stem cells express the pericyte marker 3G5 in culture and show enhanced chondrogenesis in hypoxic conditions.

Science.gov (United States)

Khan, Wasim S; Adesida, Adetola B; Tew, Simon R; Lowe, Emma T; Hardingham, Timothy E

2010-06-01

Bone marrow-derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in some cells. In this study, bone marrow-derived stem cells were characterized and the effects of hypoxia on chondrogenesis investigated. Adherent bone marrow colony-forming cells were characterized for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions. The cells stained strongly for markers of adult mesenchymal stem cells, and a high number of cells were also positive for the pericyte marker 3G5. The cells showed a chondrogenic response in cell aggregate cultures and, in lowered oxygen, there was increased matrix accumulation of proteoglycan, but less cell proliferation. In hypoxia, there was increased expression of key transcription factor SOX6, and of collagens II and XI, and aggrecan. Pericytes are a candidate stem cell in many tissue, and our results show that bone marrow-derived mesenchymal stem cells express the pericyte marker 3G5. The response to chondrogenic culture in these cells was enhanced by lowered oxygen tension. This has important implications for tissue engineering applications of bone marrow-derived stem cells. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Edge enhancement improves disruptive camouflage by emphasising false edges and creating pictorial relief.

Science.gov (United States)

Egan, John; Sharman, Rebecca J; Scott-Brown, Kenneth C; Lovell, Paul George

2016-12-06

Disruptive colouration is a visual camouflage composed of false edges and boundaries. Many disruptively camouflaged animals feature enhanced edges; light patches are surrounded by a lighter outline and/or a dark patches are surrounded by a darker outline. This camouflage is particularly common in amphibians, reptiles and lepidopterans. We explored the role that this pattern has in creating effective camouflage. In a visual search task utilising an ultra-large display area mimicking search tasks that might be found in nature, edge enhanced disruptive camouflage increases crypsis, even on substrates that do not provide an obvious visual match. Specifically, edge enhanced camouflage is effective on backgrounds both with and without shadows; i.e. this is not solely due to background matching of the dark edge enhancement element with the shadows. Furthermore, when the dark component of the edge enhancement is omitted the camouflage still provided better crypsis than control patterns without edge enhancement. This kind of edge enhancement improved camouflage on all background types. Lastly, we show that edge enhancement can create a perception of multiple surfaces. We conclude that edge enhancement increases the effectiveness of disruptive camouflage through mechanisms that may include the improved disruption of the object outline by implying pictorial relief.

How large-scale subsidence affects stratocumulus transitions

Directory of Open Access Journals (Sweden)

J. J. van der Dussen

2016-01-01

Full Text Available Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP budget from large-eddy simulation (LES results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

Uranyl peroxide enhanced nuclear fuel corrosion in seawater.

Science.gov (United States)

Armstrong, Christopher R; Nyman, May; Shvareva, Tatiana; Sigmon, Ginger E; Burns, Peter C; Navrotsky, Alexandra

2012-02-07

The Fukushima-Daiichi nuclear accident brought together compromised irradiated fuel and large amounts of seawater in a high radiation field. Based on newly acquired thermochemical data for a series of uranyl peroxide compounds containing charge-balancing alkali cations, here we show that nanoscale cage clusters containing as many as 60 uranyl ions, bonded through peroxide and hydroxide bridges, are likely to form in solution or as precipitates under such conditions. These species will enhance the corrosion of the damaged fuel and, being thermodynamically stable and kinetically persistent in the absence of peroxide, they can potentially transport uranium over long distances.

[A case of primary central nervous system anaplastic lymphoma kinase positive anaplastic large cell lymphoma manifested as a unilateral pachymeningits].

Science.gov (United States)

Fujisawa, Etsuco; Shibayama, Hidehiro; Mitobe, Fumi; Katada, Fumiaki; Sato, Susumu; Fukutake, Toshio

2017-11-25

There have been 23 reports of primary central nervous system anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma in the literature. Here we report the 24th case of a 40-year-old man who presented with occipital headache for one month. His contrast-enhanced brain MRI showed enhancement around the right temporal lobe, which suggested a diagnosis of hypertrophic pachymeningitis. He improved with steroid therapy. After discharge, however, he was readmitted with generalized convulsive seizures. Finally, he was diagnosed as primary central nervous system ALK-positive anaplastic large cell lymphoma by brain biopsy. Primary central nervous system lymphoma invading dura matter can rarely manifests as a unilateral pachymeningitis. Therefore, in case of pachymeningitis, we should pay attention to the possibility of infiltration of lymophoma with meticulous clinical follow-up.

Refractive index dependent local electric field enhancement in cylindrical gold nanohole

International Nuclear Information System (INIS)

Zhu Jian

2011-01-01

We report on the local electric field characters in a long cylindrical gold nanohole. Theoretical calculation results based on quasi-static model show that the local environmental dielectric constant dependent electric field intensity and field distribution in the gold nanohole show quite unique properties, different from those in the thin gold nanotube. Because of the thick gold wall, no plasmon hybridization exists. So there is only one resonance frequency taking place, and the intense local field has been focused into the gold nanohole. Our main finding is that, the local field in the nanohole is largely dependent on the inner hole refractive index and outer environmental refractive index. The competition between inner hole and outer polarization leads to a non-monotonic change of the local field intensity with increasing the dielectric constant of the nanohole. This refractive index controlled local field enhancement in cylindrical gold nanohole presents a potential for tunable surface-enhanced fluorescence and novel nano-optical biosensing applications.

A Variable Order Fractional Differential-Based Texture Enhancement Algorithm with Application in Medical Imaging.

Directory of Open Access Journals (Sweden)

Qiang Yu

Full Text Available Texture enhancement is one of the most important techniques in digital image processing and plays an essential role in medical imaging since textures discriminate information. Most image texture enhancement techniques use classical integral order differential mask operators or fractional differential mask operators using fixed fractional order. These masks can produce excessive enhancement of low spatial frequency content, insufficient enhancement of large spatial frequency content, and retention of high spatial frequency noise. To improve upon existing approaches of texture enhancement, we derive an improved Variable Order Fractional Centered Difference (VOFCD scheme which dynamically adjusts the fractional differential order instead of fixing it. The new VOFCD technique is based on the second order Riesz fractional differential operator using a Lagrange 3-point interpolation formula, for both grey scale and colour image enhancement. We then use this method to enhance photographs and a set of medical images related to patients with stroke and Parkinson's disease. The experiments show that our improved fractional differential mask has a higher signal to noise ratio value than the other fractional differential mask operators. Based on the corresponding quantitative analysis we conclude that the new method offers a superior texture enhancement over existing methods.

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

Science.gov (United States)

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-01

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

Meningeal enhancement on MRI after craniotomy

International Nuclear Information System (INIS)

Nomura, Motohiro; Hasegawa, Mitsuhiro; Yamashima, Tetsumori; Yamashita, Junkoh; Suzuki, Masayuki

1991-01-01

Gd-DPTA-enhanced MR images in 94 patients who had undergone craniotomy were studied, with particular attention paid to the meningeal enhancement. Such enhancement was noted in 26 of the 94 (27.6%) in the portion surrounding the craniotomy site. Meningeal enhancement, presumably of the subdural neomembrane, was apparent as a third line of a high signal intensity on T 1 -weighted MR images. The outer two high-intensity lines were derived from fat in the subcutaneous tissues of the scalp and fat in the bone marrow of the calvaria. We designated this characteristic enhancement as a 'triple white line'. Of the 26 patients with meningeal enhancement, 22 cases (23.4%) showed such a 'triple white line', 11 cases (11.7%) showed falx enhancement, and 12 cases (12.8%) showed tentorial enhancement. The intervals between surgery and the appearance of the meningeal enhancement ranged from 4 days to 88 weeks. A small amount of bleeding into the dura-arachnoid interface induced by surgery might result in the subdural neomembrane, as has previously been reported. This neomembrane might be enhanced by the leakage of Gd-DTPA through the proliferating capillaries. As meningeal enhancement occurs in approximately a third of the cases following craniotomy, much care should be taken in the differential diagnosis of the infection, inflammation, and metastasis or dissemination of malignant brain tumors. (author)

Water-enhanced solvation of organics

Energy Technology Data Exchange (ETDEWEB)

Lee, Jane H. [Univ. of California, Berkeley, CA (United States)

1993-07-01

Water-enhanced solvation (WES) was explored for Lewis acid solutes in Lewis base organic solvents, to develop cheap extract regeneration processes. WES for solid solutes was determined from ratios of solubilities of solutes in water-sat. and low-water solvent; both were determined from solid-liquid equilibrium. Vapor-headspace analysis was used to determine solute activity coefficients as function of organic phase water concentration. WES magnitudes of volatile solutes were normalized, set equal to slope of log γ_s vs x_w/x_s curve. From graph shape Δ(log γ_s) represents relative change in solute activity coefficient. Solutes investigated by vapor-headspace analysis were acetic acid, propionic acid, ethanol, 1,2-propylene glycol, 2,3-butylene glycol. Monocarboxylic acids had largest decrease in activity coefficient with water addition followed by glycols and alcohols. Propionic acid in cyclohexanone showed greatest water-enhancement Δ(log γ_acid)/Δ(x_w/x_acid) = -0.25. In methylcyclohexanone, the decrease of the activity coefficient of propionic acid was -0.19. Activity coefficient of propionic acid in methylcyclohexanone stopped decreasing once the water reached a 2:1 water to acid mole ratio, implying a stoichiometric relation between water, ketone, and acid. Except for 2,3-butanediol, activity coefficients of the solutes studied decreased monotonically with water content. Activity coefficient curves of ethanol, 1,2-propanediol and 2,3-butanediol did not level off at large water/solute mole ratio. Solutes investigated by solid-liquid equilibrium were citric acid, gallic acid, phenol, xylenols, 2-naphthol. Saturation concentration of citric acid in anhydrous butyl acetate increased from 0.0009 to 0.087 mol/L after 1.3 % (g/g) water co-dissolved into organic phase. Effect of water-enhanced solvation for citric acid is very large but very small for phenol and its derivatives.

ICAM-1-based rabies virus vaccine shows increased infection and activation of primary murine B cells in vitro and enhanced antibody titers in-vivo.

Directory of Open Access Journals (Sweden)

James E Norton

Full Text Available We have previously shown that live-attenuated rabies virus (RABV-based vaccines infect and directly activate murine and human primary B cells in-vitro, which we propose can be exploited to help develop a single-dose RABV-based vaccine. Here we report on a novel approach to utilize the binding of Intracellular Adhesion Molecule-1 (ICAM-1 to its binding partner, Lymphocyte Function-associated Antigen-1 (LFA-1, on B cells to enhance B cell activation and RABV-specific antibody responses. We used a reverse genetics approach to clone, recover, and characterize a live-attenuated recombinant RABV-based vaccine expressing the murine Icam1 gene (rRABV-mICAM-1. We show that the murine ICAM-1 gene product is incorporated into virus particles, potentially exposing ICAM-1 to extracellular binding partners. While rRABV-mICAM-1 showed 10-100-fold decrease in viral titers on baby hamster kidney cells compared to the parental virus (rRABV, rRABV-mICAM-1 infected and activated primary murine B cells in-vitro more efficiently than rRABV, as indicated by significant upregulation of CD69, CD40, and MHCII on the surface of infected B cells. ICAM-1 expression on the virus surface was responsible for enhanced B cell infection since pre-treating rRABV-mICAM-1 with a neutralizing anti-ICAM-1 antibody reduced B cell infection to levels observed with rRABV alone. Furthermore, 100-fold less rRABV-mICAM-1 was needed to induce antibody titers in immunized mice equivalent to antibody titers observed in rRABV-immunized mice. Of note, only 10(3 focus forming units (ffu/mouse of rRABV-mICAM-1 was needed to induce significant anti-RABV antibody titers as early as five days post-immunization. As both speed and potency of antibody responses are important in controlling human RABV infection in a post-exposure setting, these data show that expression of Icam1 from the RABV genome, which is then incorporated into the virus particle, is a promising strategy for the development of a

Enhanced photochemistry on metal surfaces

International Nuclear Information System (INIS)

Goncher, G.M.; Parsons, C.A.; Harris, C.B.

1984-01-01

Due to the fast relaxation of molecular excited states in the vicinity of a metal or semiconductor surface, few observations of surface photochemistry have been reported. The following work concerns the surface-enhanced photo-reactions of a variety of physisorbed molecules on roughened Ag surfaces. In summary, photodecomposition leads to a graphitic surface carbon product which is monitored via surface-enhanced Raman scattering. In most cases an initial two-photon molecular absorption step followed by further absorption and fragmentation is thought to occur. Enhancement of the incident fields occurs through roughness-mediated surface plasmon resonances. This mechanism provides the amplified electromagnetic surface fields responsible for the observed photodecomposition. The photodecomposition experiments are performed under ultra-high vacuum. Surface characterization of the roughened surfaces was done by Scanning Electron Microscopy (SEM), and electron-stimulated emission. The SEM revealed morphology on the order of 300-400 A. This size of roughness feature, when modelled as isolated spheres should exhibit the well-known Mie resonances for light of the correct wavelengths. For protrusions existing on a surface these Mie resonances can be thought of as a coupling of the light with the surface plasmon. Experimental verification of these resonances was provided by the electron-stimulated light emission results. These showed that a polished Ag surface emitted only the expected transition radiation at the frequency of the Ag bulk plasmon. Upon roughening, however, a broad range of lower frequencies extending well into the visible are seen from electron irradiation of the surface. Large enhancements are expected for those frequencies which are able to couple into the surface modes

Terahertz Near-Field Imaging Using Enhanced Transmission through a Single Subwavelength Aperture

Science.gov (United States)

Ishihara, Kunihiko; Ikari, Tomofumi; Minamide, Hiroaki; Shikata, Jun-ichi; Ohashi, Keishi; Yokoyama, Hiroyuki; Ito, Hiromasa

2005-07-01

We demonstrate terahertz (THz) near-field imaging using resonantly enhanced transmission of THz-wave radiation (λ˜ 200 μm) through a bull’s eye structure (a single subwavelength aperture surrounded by concentric periodic grooves in a metal plate). The bull’s eye structure shows extremely large enhanced transmission, which has the advantage for a single subwavelength aperture. The spatial resolution for the bull’s eye structure (with an aperture diameter d=100 μm) is evaluated in the near-field region, and a resolution of 50 μm (corresponding to λ/4) is achieved. We obtain the THz near-field images of the subwavelength metal pattern with a spatial resolution below the diffraction limit.

Enhancement MRI evaluation of neuroblastoma staging in children

International Nuclear Information System (INIS)

Li Xin; Wang Chunxiang; Zhao Bin; Liu Peifang

2002-01-01

Objective: To evaluate the value and limitation of Gd-DTPA enhanced MRI for neuroblastoma staging in children. Methods: Twelve cases of neuroblastoma proved by operation or bone marrow aspiration were examined by gadolinium-enhanced MRI. The age ranged from seven months to five years, mean 3.7 years. Eight tumors originated from adrenal, and four from posterior mediastinum. Conventional sequences, double dose gadolinium-enhanced MRI, and 3D CEMRA were used in all patients. Six cases were examined by CT in same time. Imaging staging on surgic-histopathological-based International Neuroblastoma Staging System (INSS) was performed. Results: Six patients were staged by CT, including stage I-II in 2 cases, stage III in 4 cases, and stage IV in none. Twelve patients were staged by conventional MRI, including stage I-II in 2 cases, stage III in 9 cases, and stage IV in 1 case. Twelve patients were staged by double dose gadolinium-enhanced MRI, including stage I-II in 1 case, stage III in 1 case, and stage IV in 10 cases. Conclusion: Gadolinium-enhanced MRI was a single best imaging modality for neuroblastoma, most useful for distal to diaphragm metastasis, dumbbell tumor intraspinal extension, and bone marrow metastasis that was not detected by aspirate examination. Enhancement MRI was important in evaluating the therapy and was also helpful in assessing the therapeutic efficacy and relapse. 3D CEMRA helps demonstrate large vascular encasement and tumor erosion into important organs, and it is useful in assessing the respectability. Long examination time and lack in showing the characteristic calcium were the limitations

Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement

Directory of Open Access Journals (Sweden)

Shamsa Akbar

Full Text Available ABSTRACT Background: Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Results: Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates were able to degrade 84.4% and 78.6% of the initial concentration of chlorpyrifos (100 mg L-1 within a period of only 10 days. Based on 16S rRNA sequence analysis, these strains were identified as Achromobacter xylosoxidans (JCp4 and Ochrobactrum sp. (FCp1. These strains exhibited the ability to degrade chlorpyrifos in sterilized as well as non-sterilized soils, and were able to degrade 93-100% of the input concentration (200 mg kg-1 within 42 days. The rate of degradation in inoculated soils ranged from 4.40 to 4.76 mg-1 kg-1 d-1 with rate constants varying between 0.047 and 0.069 d-1. These strains also displayed substantial plant growth promoting traits such as phosphate solubilization, indole acetic acid production and ammonia production both in absence as well as in the presence of chlorpyrifos. However, presence of chlorpyrifos (100 and 200 mg L-1 was found to have a negative effect on indole acetic acid production and phosphate solubilization with percentage reduction values ranging between 2.65-10.6% and 4.5-17.6%, respectively. Plant growth experiment demonstrated that chlorpyrifos has a negative effect on plant growth and causes a decrease in parameters such as percentage germination, plant height and biomass. Inoculation of soil with chlorpyrifos-degrading strains was found to enhance plant growth significantly in terms of plant length and weight. Moreover, it was noted that these strains degraded chlorpyrifos at an increased rate (5

Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement.

Science.gov (United States)

Akbar, Shamsa; Sultan, Sikander

2016-01-01

Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates were able to degrade 84.4% and 78.6% of the initial concentration of chlorpyrifos (100mgL(-1)) within a period of only 10 days. Based on 16S rRNA sequence analysis, these strains were identified as Achromobacter xylosoxidans (JCp4) and Ochrobactrum sp. (FCp1). These strains exhibited the ability to degrade chlorpyrifos in sterilized as well as non-sterilized soils, and were able to degrade 93-100% of the input concentration (200mgkg(-1)) within 42 days. The rate of degradation in inoculated soils ranged from 4.40 to 4.76mg(-1)kg(-1)d(-1) with rate constants varying between 0.047 and 0.069d(-1). These strains also displayed substantial plant growth promoting traits such as phosphate solubilization, indole acetic acid production and ammonia production both in absence as well as in the presence of chlorpyrifos. However, presence of chlorpyrifos (100 and 200mgL(-1)) was found to have a negative effect on indole acetic acid production and phosphate solubilization with percentage reduction values ranging between 2.65-10.6% and 4.5-17.6%, respectively. Plant growth experiment demonstrated that chlorpyrifos has a negative effect on plant growth and causes a decrease in parameters such as percentage germination, plant height and biomass. Inoculation of soil with chlorpyrifos-degrading strains was found to enhance plant growth significantly in terms of plant length and weight. Moreover, it was noted that these strains degraded chlorpyrifos at an increased rate (5.69mg(-1)kg(-1)d(-1)) in planted soil. The

Enhanced Confinement Scenarios Without Large Edge Localized Modes in Tokamaks: Control, Performance, and Extrapolability Issues for ITER

Energy Technology Data Exchange (ETDEWEB)

Maingi, R [PPPL

2014-07-01

Large edge localized modes (ELMs) typically accompany good H-mode confinement in fusion devices, but can present problems for plasma facing components because of high transient heat loads. Here the range of techniques for ELM control deployed in fusion devices is reviewed. The two baseline strategies in the ITER baseline design are emphasized: rapid ELM triggering and peak heat flux control via pellet injection, and the use of magnetic perturbations to suppress or mitigate ELMs. While both of these techniques are moderately well developed, with reasonable physical bases for projecting to ITER, differing observations between multiple devices are also discussed to highlight the needed community R & D. In addition, recent progress in ELM-free regimes, namely Quiescent H-mode, I-mode, and Enhanced Pedestal H-mode is reviewed, and open questions for extrapolability are discussed. Finally progress and outstanding issues in alternate ELM control techniques are reviewed: supersonic molecular beam injection, edge electron cyclotron heating, lower hybrid heating and/or current drive, controlled periodic jogs of the vertical centroid position, ELM pace-making via periodic magnetic perturbations, ELM elimination with lithium wall conditioning, and naturally occurring small ELM regimes.

Surface-Enhanced Raman Spectroscopy of Dye and Thiol Molecules Adsorbed on Triangular Silver Nano structures: A Study of Near-Field Enhancement, Localization of Hot-Spots, and Passivation of Adsorbed Carbonaceous Species

International Nuclear Information System (INIS)

Goncalves, M.R.; Marti, O.; Fabian Enderle, F.

2012-01-01

Surface-enhanced Raman spectroscopy (SERS) of thiols and dye molecules adsorbed on triangular silver nanostructures was investigated. The SERS hot-spots are localized at the edges and corners of the silver triangular particles. AFM and SEM measurements permit to observe many small clusters formed at the edges of triangular particles fabricated by nanosphere lithography. Finite-element calculations show that near-field enhancements can reach values of more than 200 at visible wavelengths, in the gaps between small spherical particles and large triangular particles, although for the later no plasmon resonance was found at the wavelengths investigated. The regions near the particles showing strong near-field enhancement are well correlated with spatial localization of SERS hot-spots done by confocal microscopy. Silver nanostructures fabricated by thermal evaporation present strong and fast fluctuating SERS activity, due to amorphous carbon contamination. Thiols and dye molecules seem to be able to passivate the undesired SERS activity on fresh evaporated silver. excitation: by far-field illumination of metal nanostructures or rough metal Raman scattering cross-section of gold-palladium target Temporal Fluctuation in SERS Temporal and spectral fluctuations.

Surface-plasmon-enhanced lasing emission based on polymer distributed feedback laser

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dingke, E-mail: dingke.zhang@gmail.com, E-mail: shijianchen@gmail.com [School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331 (China); Chen, Shijian, E-mail: dingke.zhang@gmail.com, E-mail: shijianchen@gmail.com; Huang, Yingzhou; Zhang, Zhen [School of Physics, Chongqing University, Chongqing 401331 (China); Wang, Yanping; Ma, Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2015-01-14

Optical losses associated with the metallic contacts necessary for charge injection are an obstacle to the development of electrically pumped organic lasers. In this work, we show that it is possible to overcome these losses by introducing surface plasmons (SPs) in a distributed feedback laser to enhance the lasing emission. We perform a detailed study of the SPs influence on the lasing emission. We experimentally show that enhanced lasing emission has been successfully achieved in the presence of a metal electrode. The laser emission is strongly dependent on the thickness of Ag layer. By optimizing the thickness of Ag layer, surface-plasmon-enhanced lasing emission has been achieved with much reduced thresholds and higher intensity. When the thickness of the Ag layer increases to 50 nm, the device exhibits ten-fold emission intensity and a fifth of excitation threshold comparing with Ag-free one. The finite-difference time-domain (FDTD) results show that large field intensity is built at the 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) -4H-pyran:/poly(9-vinylcarbazole)Ag interface, which could lead to a strong coupling between lasing and SPs, and consequently a much enhanced laser emission at the photon energy of around 2.02 eV (615 nm). Our FDTD simulations gave an explanation of the effects of the SPs on lasing operation in the periodic structures. The use of SPs would lead to a new class of highly efficient solid-state laser sources and provide a new path to achieve electrically pumped organic lasers.

Functional analysis of limb transcriptional enhancers in the mouse.

Science.gov (United States)

Nolte, Mark J; Wang, Ying; Deng, Jian Min; Swinton, Paul G; Wei, Caimiao; Guindani, Michele; Schwartz, Robert J; Behringer, Richard R

2014-01-01

Transcriptional enhancers are genomic sequences bound by transcription factors that act together with basal transcriptional machinery to regulate gene transcription. Several high-throughput methods have generated large datasets of tissue-specific enhancer sequences with putative roles in developmental processes. However, few enhancers have been deleted from the genome to determine their roles in development. To understand the roles of two enhancers active in the mouse embryonic limb bud we deleted them from the genome. Although the genes regulated by these enhancers are unknown, they were selected because they were identified in a screen for putative limb bud-specific enhancers associated with p300, an acetyltransferase that participates in protein complexes that promote active transcription, and because the orthologous human enhancers (H1442 and H280) drive distinct lacZ expression patterns in limb buds of embryonic day (E) 11.5 transgenic mice. We show that the orthologous mouse sequences, M1442 and M280, regulate dynamic expression in the developing limb. Although significant transcriptional differences in enhancer-proximal genes in embryonic limb buds accompany the deletion of M1442 and M280 no gross limb malformations during embryonic development were observed, demonstrating that M1442 and M280 are not required for mouse limb development. However, M280 is required for the development and/or maintenance of body size; M280 mice are significantly smaller than controls. M280 also harbors an "ultraconserved" sequence that is identical between human, rat, and mouse. This is the first report of a phenotype resulting from the deletion of an ultraconserved element. These studies highlight the importance of determining enhancer regulatory function by experiments that manipulate them in situ and suggest that some of an enhancer's regulatory capacities may be developmentally tolerated rather than developmentally required. © 2014 Wiley Periodicals, Inc.

BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects.

Science.gov (United States)

Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

2015-01-01

The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m(2)/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration.

Age distribution of human gene families shows significant roles of both large- and small-scale duplications in vertebrate evolution.

Science.gov (United States)

Gu, Xun; Wang, Yufeng; Gu, Jianying

2002-06-01

The classical (two-round) hypothesis of vertebrate genome duplication proposes two successive whole-genome duplication(s) (polyploidizations) predating the origin of fishes, a view now being seriously challenged. As the debate largely concerns the relative merits of the 'big-bang mode' theory (large-scale duplication) and the 'continuous mode' theory (constant creation by small-scale duplications), we tested whether a significant proportion of paralogous genes in the contemporary human genome was indeed generated in the early stage of vertebrate evolution. After an extensive search of major databases, we dated 1,739 gene duplication events from the phylogenetic analysis of 749 vertebrate gene families. We found a pattern characterized by two waves (I, II) and an ancient component. Wave I represents a recent gene family expansion by tandem or segmental duplications, whereas wave II, a rapid paralogous gene increase in the early stage of vertebrate evolution, supports the idea of genome duplication(s) (the big-bang mode). Further analysis indicated that large- and small-scale gene duplications both make a significant contribution during the early stage of vertebrate evolution to build the current hierarchy of the human proteome.

Enhanced photosensitized degradation of rhodamine B on CdS/TiO{sub 2} nanocomposites under visible light irradiation

Energy Technology Data Exchange (ETDEWEB)

Li, Wenjuan [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Sciences and Engineering, Nanjing University of Information Sciences and Engineering, Nanjing 210044 (China); Research Institute of Photocatalysis, State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou 350002 (China); Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165 (China); Cui, Xiaoli [Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165 (China); Wang, Peixian; Shao, Yu [Research Institute of Photocatalysis, State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou 350002 (China); Li, Danzhen, E-mail: dzli@fzu.edu.cn [Research Institute of Photocatalysis, State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou 350002 (China); Teng, Fei [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Sciences and Engineering, Nanjing University of Information Sciences and Engineering, Nanjing 210044 (China)

2013-09-01

Graphical abstract: The photosensitized degradation of RhB was largely enhanced by the synergistic effect of the RhB and CdS/TiO{sub 2} nanocomposite. The composite of the two inorganic semiconductors with appropriate oxidation reduction energy levels enhanced the charge separation and extended the absorption response to visible region. - Highlights: • CdS/TiO{sub 2} nanocomposites were synthesized by a simple hydrothermal method. • Samples prepared at 200 °C, 12 h, CdS/TiO{sub 2} = 12% possessed the best activity. • The photosensitized degradation of RhB was largely enhanced by the composite. • The better activity was due to the synergistic effect of the RhB and CdS/TiO{sub 2}. - Abstract: Visible-light-driven photocatalysts, CdS/TiO{sub 2} nanocomposites were synthesized by a simple hydrothermal method. Their formation and structures were characterized by X-ray diffractometer, transmission electron microscopy, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Taking rhodamine B (RhB) as a model, their photocatalytic activities in aqueous phase under visible light irradiation (420 < λ < 800 nm) were tested. The results showed that the composite of CdS and TiO{sub 2} with appropriate oxidation reduction energy levels enhanced the charge separation and extended the absorption response into visible light region. Thus, the photosensitized degradation of RhB was largely enhanced. The degradation mechanism was explored concretely.

Large negative magnetoresistance in reactive sputtered polycrystalline GdNx films

KAUST Repository

Mi, W. B.; Guo, Z. B.; Duan, X. F.; Zhang, X. J.; Bai, H. L.

2013-01-01

Polycrystalline ferromagnetic GdN x films were fabricated at different N2 flow rates ( fN2 ) to modify N-vacancy concentration so as to study its influence on electrotransport. Metal-semiconductor transition appears at Curie temperature (TC ) of ∼40 K. Temperature-dependent magnetoresistance (MR) shows a peak at T C. The films at fN2  = 5, 10, 15, and 20 sccm show MR of −38%, −42%, −46%, and −86% at 5 K and 50 kOe, respectively. Above 15 K, MR is from colossal MR and from both colossal and tunneling MR below 15 K. The enhanced MR at fN2  = 20 sccm is attributed to large spin polarization of half-metallicity in GdN x with low N vacancies.

Large negative magnetoresistance in reactive sputtered polycrystalline GdNx films

KAUST Repository

Mi, W. B.

2013-06-07

Polycrystalline ferromagnetic GdN x films were fabricated at different N2 flow rates ( fN2 ) to modify N-vacancy concentration so as to study its influence on electrotransport. Metal-semiconductor transition appears at Curie temperature (TC ) of ∼40 K. Temperature-dependent magnetoresistance (MR) shows a peak at T C. The films at fN2  = 5, 10, 15, and 20 sccm show MR of −38%, −42%, −46%, and −86% at 5 K and 50 kOe, respectively. Above 15 K, MR is from colossal MR and from both colossal and tunneling MR below 15 K. The enhanced MR at fN2  = 20 sccm is attributed to large spin polarization of half-metallicity in GdN x with low N vacancies.

creating social presence in large classes

African Journals Online (AJOL)

Social presence refers to the ability of students to project themselves as 'real people' in an online learning community. While it is difficult to create social presence in large classes, educational technologies can enhance the social dimension of online learning if educators relinquish the use of technology as an instrument of ...

Different goods, different effects: Exploring the effects of generalized social trust in large-N collective action

DEFF Research Database (Denmark)

Sønderskov, Kim Mannemar

2009-01-01

Does generalized social trust help solve large-N collective action problems? This paper argues so, offering a novel explanation for the relationship: People tend to cooperate if they expect others to be cooperating, which implies that people holding generalized social trust more readily cooperate...... in large-N dilemmas because they expect that most people will cooperate. The paper tests the explanation in a rigorous design. The analyses show a positive, robust effect of generalized social trust on public good provision, but no effect is found in a joint product situation. This supports the hypothesis......, indicating that trust specifically enhances cooperation in collective action dilemmas....

Spatially Resolved Large Magnetization in Ultrathin BiFeO3

KAUST Repository

Guo, Er-Jia

2017-06-19

Here, a quantitative magnetic depth profile across the planar interfaces in BiFeO3 /La0.7 Sr0.3 MnO3 (BFO/LSMO) superlattices using polarized neutron reflectometry is obtained. An enhanced magnetization of 1.83 ± 0.16 μB /Fe in BFO layers is observed when they are interleaved between two manganite layers. The enhanced magnetic order in BFO persists up to 200 K. The depth dependence of magnetic moments in BFO/LSMO superlattices as a function of the BFO layer thickness is also explored. The results show the enhanced net magnetic moment in BFO from the LSMO/BFO interface extends 3-4 unit cells into BFO. The interior part of a thicker BFO layer has a much smaller magnetization, suggesting it still keeps the small canted AFM state. The results exclude charge transfer, intermixing, epitaxial strain, and octahedral rotations/tilts as dominating mechanisms for the large net magnetization in BFO. An explanation-one suggested by others previously and consistent with the observations-attributes the temperature dependence of the net magnetization of BFO to strong orbital hybridization between Fe and Mn across the interfaces. Such orbital reconstruction would establish an upper temperature limit for magnetic ordering of BFO.

Gd-EOB-DTPA enhanced MRI of the liver: Correlation of relative hepatic enhancement, relative renal enhancement, and liver to kidneys enhancement ratio with serum hepatic enzyme levels and eGFR

Energy Technology Data Exchange (ETDEWEB)

Talakic, Emina; Steiner, Jürgen; Kalmar, Peter; Lutfi, Andre [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Quehenberger, Franz [Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Auenbruggerplatz 2, 8036 Graz (Austria); Reiter, Ursula; Fuchsjäger, Michael [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Schöllnast, Helmut, E-mail: helmut.schoellnast@medunigraz.at [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria)

2014-04-15

Objectives: To assess the correlation of relative hepatic enhancement (RHE), relative renal enhancement (RRE) and liver to kidneys enhancement ratio (LKR) with serum hepatic enzyme levels and eGFR in Gd-EOB-DTPA enhanced MRI of the liver and to assess threshold levels for predicting enhancement of the liver parenchyma. Methods: Data of 75 patients who underwent Gd-EOB-DTPA enhanced MRI of the liver were collected. Images were obtained before contrast injection, during the early arterial phase, late arterial phase, venous phase, delayed phase, and hepatobiliary phase which was 20 min after Gd-EOB-DTPA administration. Signal intensity of the liver and the kidneys in all phases was defined using region-of-interest measurements for relative enhancement calculation. Serum hepatic enzyme levels and eGFR were available in all patients. Spearman correlation test was used to test the correlation of RHE, RRE and LKR with serum hepatic enzyme levels and eGFR. Results: In the hepatobiliary phase all serum hepatic enzymes were significantly correlated with RHE; total bilirubin (TBIL) and cholin esterase (CHE) showed strongest correlations. TBIL and CHE were significantly correlated with RRE in the arterial phases. TBIL and CHE were significantly correlated with LKR in the arterial phase and hepatobiliary phase. eGFR showed no correlation. Conclusions: In Gd-EOB-DTPA enhanced MRI, TBIL and CHE levels may predict RHE, RRE and LKR.

Dural enhancement with primary calvarial lesions.

Science.gov (United States)

Arana, E; Martí-Bonmatí, L; Ricart, V; Pérez-Ebrí, M

2004-11-01

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

Dural enhancement with primary calvarial lesions

Energy Technology Data Exchange (ETDEWEB)

Arana, E. [Clinica Quiron, Department of Radiology, Valencia (Spain); Marti-Bonmati, L. [Clinica Quiron, Department of Radiology, Valencia (Spain); Hospital Universitario Dr. Peset, Department of Radiology, Valencia (Spain); Ricart, V. [Hospital de la Ribera, Department of Radiology, Valencia (Spain); Perez-Ebri, M. [Hospital Universitario Dr. Peset, Department of Pathology, Valencia (Spain)

2004-11-01

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign (''dural tail'') on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms. (orig.)

Clinical significance of nerve root enhancement in contrast-enhanced MR imaging of the postoperative lumbar spine

International Nuclear Information System (INIS)

Lee, Yeon Soo; Lee, Eun Ja; Kang, Si Won; Choi, Eun Seok; Song, Chang June; Kim, Jong Chul

2001-01-01

To determine the significance of nerve root contrast enhancement in patients with residual or recurrent symptomatic postoperative lumbar spine. Eighty-eight patients with 116 postoperative lumbar disc lesions causing radiating back pain underwent enhanced MR imaging. Intradural nerve root enhancement was quantified by pixel measurement, and affected nerve roots were compared before and after contrast administration. Extradural nerve root enhancement was assessed visually, and nerve root enhancement and clinical symptoms were correlated. Associated lesions such as recurrent disc herniation, scar tissue, nerve root thickening and nerve root displacement were also evaluated. Of 26 cases (22.4%) involving intradural nerve root enhancement, 22 (84.6%) showed significant clinical symptoms (p=0.002). and of 59 (50.9%) demonstrating extradural enhancement, clinical symptoms showed significant correlation in 47 (79.7%) (p=0.001). Nerve root enhancement, including eleven cases where this was both intra-and extradural, showed highly significant association with clinical symptoms in 74 of the 116 cases (63.8%) (p=0.000). Among 33 cases (28.4%) of recurrent disc herniation, nerve root enhancement was observed in 28 (84.8%) and in 24 of these 28 (85.7%), significant correlation with clinical symptoms was observed (p=0.000). Where epidural fibrosis was present, correlation between nerve root enhancement and clinical symptoms was not significant (p>0.05). Nerve root thickening and displaced nerve root were, however, significantly associated with symptoms (87.2% and 88.6%, respectively). In patients with postoperative lumbar spine, the association between nerve root enhancement revealed by MRI and clinical symptoms was highly significant

Recent Advances in Skin Penetration Enhancers for Transdermal Gene and Drug Delivery.

Science.gov (United States)

Amjadi, Morteza; Mostaghaci, Babak; Sitti, Metin

2017-01-01

There is a growing interest in transdermal delivery systems because of their noninvasive, targeted, and on-demand delivery of gene and drugs. However, efficient penetration of therapeutic compounds into the skin is still challenging largely due to the impermeability of the outermost layer of the skin, known as stratum corneum. Recently, there have been major research activities to enhance the skin penetration depth of pharmacological agents. This article reviews recent advances in the development of various strategies for skin penetration enhancement. We show that approaches such as ultrasound waves, laser, and microneedle patches have successfully been employed to physically disrupt the stratum corneum structure for enhanced transdermal delivery. Rather than physical approaches, several non-physical route have also been utilized for efficient transdermal delivery across the skin barrier. Finally, we discuss some clinical applications of transdermal delivery systems for gene and drug delivery. This paper shows that transdermal delivery devices can potentially function for diverse healthcare and medical applications while further investigations are still necessary for more efficient skin penetration of gene and drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Multiple FNH-Like Lesions in a Patient with Chronic Budd-Chiari Syndrome: Gd-EOB-Enhanced MRI and BR1 CEUS Findings

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Caroline Newerla

2012-01-01

Full Text Available A-26-year old female patient with chronic Budd-Chiari syndrome due to different underlying blood disorders applied for a two-year followup of the liver with Gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic-acid-(Gd-EOB-DTPA- enhanced MRI. The liver function tests were raised. Besides showing a progressive hepatosplenomegaly and a cirrhotic liver alteration, the MRI revealed multiple new nodular lesions in all liver segments. These lesions showed typical patterns in the precontrast images, while there was an arterial and a persistent portal venous enhancement. In the hepatobiliary liver-specific late phase, a central “washout” and a persistent rim enhancement were observed (target sign. The additionally performed contrast-enhanced ultrasonography showed a strong zentrifugal arterial enhancement of the lesions followed by an isoechoic enhancement in the portal venous and delayed liver phase. Histologically these lesions turned out as focal nodular hyperplasias (FNH or FNH-like lesions, also known as large regenerative nodules (LRNs. Differentiation between regenerative nodules like LRN and hepatocellular carcinoma (HCC in cirrhotic livers is crucial, and the target sign in the hepatobiliary phase of Gd-EOB-DTPA as well as the centrifugal arterial enhancement followed by an isoenhancement during a CEUS might be useful for establishing the correct diagnosis of such hypervascular lesions with proliferated and likely aberrant bile ducts.

Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

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Arkadiusz Jarosław GOSZCZAK

2017-02-01

Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

STEM for Non-STEM Majors: Enhancing Science Literacy in Large Classes

Science.gov (United States)

Jin, Guang; Bierma, Tom

2013-01-01

This study evaluated a strategy using "clickers," POGIL (process oriented guided inquiry learning), and a focused science literacy orientation in an applied science course for non-STEM undergraduates taught in large classes. The effectiveness of these interventions in improving the science literacy of students was evaluated using a…

A pseudotype baculovirus expressing the capsid protein of foot-and-mouth disease virus and a T-Cell immunogen shows enhanced immunogenicity in mice

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Liu Xiangtao

2011-02-01

Full Text Available Abstract Background Foot-and-mouth disease (FMD is a highly contagious disease of livestock which causes severe economic loss in cloven-hoofed animals. Vaccination is still a major strategy in developing countries to control FMD. Currently, inactivated vaccine of FMDV has been used in many countries with limited success and safety concerns. Development of a novel effective vaccine is must. Methods In the present study, two recombinant pseudotype baculoviruses, one expressing the capsid of foot-and-mouth disease virus (FMDV under the control of a cytomegalovirus immediate early enhancer/promoter (CMV-IE, and the other the caspid plus a T-cell immunogen coding region under a CAG promoter were constructed, and their expression was characterized in mammalian cells. In addition, their immunogenicity in a mouse model was investigated. The humoral and cell-mediated immune responses induced by pseudotype baculovirus were compared with those of inactivated vaccine. Results Indirect immunofluorescence assay (IFA and indirect sandwich-ELISA (IS-ELISA showed both recombinant baculoviruses (with or without T-cell epitopes were transduced efficiently and expressed target proteins in BHK-21 cells. In mice, intramuscular inoculation of recombinants with 1 × 109 or 1 × 1010 PFU/mouse induced the production of FMDV-specific neutralizing antibodies and gamma interferon (IFN-γ. Furthermore, recombinant baculovirus with T-cell epitopes had better immunogenicity than the recombinant without T-cell epitopes as demonstrated by significantly enhanced IFN-γ production (P P Conclusions These results indicate that pseudotype baculovirus-mediated gene delivery could be a alternative strategy to develop a new generation of vaccines against FMDV infection.

Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fulvescens show highly restricted movement and habitat use over-winter

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Donnette Thayer

2017-04-01

Full Text Available The relationship between species’ size and home range size has been well studied. In practice, home range may provide a good surrogate of broad spatial coverage needed for species conservation, however, many species can show restricted movement during critical life stages, such as breeding and over-wintering. This suggests the existence of either a behavioral or habitat mediated ‘temporal bottleneck,’ where restricted or sedentary movement can make populations more susceptible to harm during specific life stages. Here, we study over-winter movement and habitat use of Lake Sturgeon (Acipenser fulvescens, the largest freshwater fish in North America. We monitored over-winter movement of 86 fish using a hydro-acoustic receiver array in the South Saskatchewan River, Canada. Overall, 20 fish remained within our study system throughout the winter. Lake Sturgeon showed strong aggregation and sedentary movement over-winter, demonstrating a temporal bottleneck. Movement was highly restricted during ice-on periods (ranging from 0.9 km/day in November and April to 0.2 km/day in mid-November to mid-March, with Lake Sturgeon seeking deeper, slower pools. We also show that Lake Sturgeon have strong aggregation behavior, where distance to conspecifics decreased (from 575 to 313 m in preparation for and during ice-on periods. Although the Lake Sturgeon we studied had access to 1100 kilometers of unfragmented riverine habitat, we show that during the over-winter period Lake Sturgeon utilized a single, deep pool (<0.1% of available habitat. The temporal discrepancy between mobile and sedentary behaviors in Lake Sturgeon suggest adaptive management is needed with more localized focus during periods of temporal bottlenecks, even for large-bodied species.

Silicon-Based Asymmetric Add-Drop Microring Resonators with Ultra-Large Through-Port Extinctions

International Nuclear Information System (INIS)

Xi, Xiao; Yun-Tao, Li; Yu-De, Yu; Jin-Zhong, Yu

2010-01-01

We theoretically simulate and experimentally demonstrate ultra-large through-port extinctions in silicon-based asymmetrically-coupled add-drop microring resonators (MRs). Through-port responses in an add-drop MR are analyzed by simulations and large extinctions are found when the MR is near-critically coupled. Accurate fabrication techniques are applied in producing a series of 20 μm-radii add-drop microrings with drop-side gap-widths in slight differences. A through-port extinction of about 42.7 dB is measured in an MR with through- and drop-side gap-width to be respectively 280nm and 295nm. The large extinction suggests about a 20.5 dB improvement from the symmetrical add-drop MR of the same size and the through-side gap-width. The experimental results are finally compared with the post-fabrication simulations, which show a gap-width tolerance of > 30 am for the through-port extinction enhancement

Optimized method for manufacturing large aspheric surfaces

Science.gov (United States)

Zhou, Xusheng; Li, Shengyi; Dai, Yifan; Xie, Xuhui

2007-12-01

Aspheric optics are being used more and more widely in modern optical systems, due to their ability of correcting aberrations, enhancing image quality, enlarging the field of view and extending the range of effect, while reducing the weight and volume of the system. With optical technology development, we have more pressing requirement to large-aperture and high-precision aspheric surfaces. The original computer controlled optical surfacing (CCOS) technique cannot meet the challenge of precision and machining efficiency. This problem has been thought highly of by researchers. Aiming at the problem of original polishing process, an optimized method for manufacturing large aspheric surfaces is put forward. Subsurface damage (SSD), full aperture errors and full band of frequency errors are all in control of this method. Lesser SSD depth can be gained by using little hardness tool and small abrasive grains in grinding process. For full aperture errors control, edge effects can be controlled by using smaller tools and amendment model with material removal function. For full band of frequency errors control, low frequency errors can be corrected with the optimized material removal function, while medium-high frequency errors by using uniform removing principle. With this optimized method, the accuracy of a K9 glass paraboloid mirror can reach rms 0.055 waves (where a wave is 0.6328μm) in a short time. The results show that the optimized method can guide large aspheric surface manufacturing effectively.

Dose Tc-99m MIBI scintimammography provide more information additive to contrast enhanced MRI in highly suspected breast cancer patients?

International Nuclear Information System (INIS)

Kim, Seong Jang; Kim, In Ju; Kim, Yong Ki; Bae, Young Tae

2000-01-01

The aim of this study was to investigate whether Tc-99m MIBI scintimammography (SMM) provide more information than contrast enhanced MRI in highly suspected breast cancer patients. This study included 32 breast lesions of 29 highly suspected patients having breast cancer. All patients were performed SMM and contrast enhanced MRI. The SMMs and contrast enhanced MRI were correlated with histopathologic results. Thirty breast lesions were diagnosed malignant diseases and 2 were diagnosed benign diseases. SMM showed 29 true positives (TP), 1 true negative (TN), 1 false positive (FP), and 1 false negative (FN). The sensitivity was 96.6%. Contrast enhanced MRI revealed 24 TP, 0 TN, 1 FP, 3 FN and 4 indeterminate cases. The sensitivity was 88.8%. In the assessment of axillary lymph node metastasis, SMM showed 9 TP, 10 TN, 0 FP, and 3 FN. The sensitivity and specificity were 75% and 100%. Contrast enhanced MRI revealed 6 TP, 9 TN, 1 FP, and 6 FN. The sensitivity and specificity were 50% and 90%. Among 4 indeterminate cases with MRI findings, SMM correctly diagnosed malignant breast diseases in 3 lesions. However, SMM showed false positive in 1 lesion. SMM could correctly diagnosed malignant breast diseases more 5 lesions than contrast enhanced MRI. SMM revealed higher sensitivity in detection of primary breast cancer and axillary LN metastasis than contrast enhanced MRI. SMMs could correctly diagnosed malignant breast diseases even if the MRI showed indeterminate findings. In highly suspected patients having breast cancer, SMM may provide additive information in detection of breast cancer if contrast enhanced MRI showed indeterminate findings but this is to be determined later by large population based study

An autopsied case of tuberculous meningitis showing interesting CT findings

International Nuclear Information System (INIS)

Abiko, Takashi; Higuchi, Hiroshi; Imada, Ryuichi; Nagai, Kenichi

1983-01-01

A 61-year-old female patient died of a neurological disorder of unknown origin one month after the first visit and was found to have had tuberculous meningitis at autopsy. CT revealed a low density area showing an enlargement of the cerebral ventricle but did not reveal contrast enhancement in the basal cistern peculiar to tuberculous meningitis. (Namekawa, K.)

Just enough inflation. Power spectrum modifications at large scales

International Nuclear Information System (INIS)

Cicoli, Michele; Downes, Sean

2014-07-01

We show that models of 'just enough' inflation, where the slow-roll evolution lasted only 50-60 e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of any possible non-slow-roll background evolution prior to the final stage of slow-roll inflation. We find a high degree of universality since most common backgrounds like fast-roll evolution, matter or radiation-dominance give rise to a power loss at large angular scales and a peak together with an oscillatory behaviour at scales around the value of the Hubble parameter at the beginning of slow-roll inflation. Depending on the value of the equation of state parameter, different pre-inflationary epochs lead instead to an enhancement of power at low-l, and so seem disfavoured by recent observational hints for a lack of CMB power at l< or similar 40. We also comment on the importance of initial conditions and the possibility to have multiple pre-inflationary stages.

Delayed enhanced MRI in intraparenchymal tumors

International Nuclear Information System (INIS)

Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

1991-01-01

Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

Northern Hemisphere Atmospheric Influence of the Solar Proton Events and Ground Level Enhancement in January 2005

Science.gov (United States)

Jackman, C. H.; Marsh, D. R.; Vitt, F. M.; Roble, R. G.; Randall, C. E.; Bernath, P. F.; Funke, B.; Lopez-Puertas, M.; Versick, S.; Stiller, G. P.;

Northern Hemisphere atmospheric influence of the solar proton events and ground level enhancement in January 2005

Directory of Open Access Journals (Sweden)

C. H. Jackman

2011-07-01

Full Text Available Solar eruptions in early 2005 led to a substantial barrage of charged particles on the Earth's atmosphere during the 16–21 January period. Proton fluxes were greatly increased during these several days and led to the production of HO_x (H, OH, HO₂ and NO_x (N, NO, NO₂, which then caused the destruction of ozone. We focus on the Northern polar region, where satellite measurements and simulations with the Whole Atmosphere Community Climate Model (WACCM3 showed large enhancements in mesospheric HO_x and NO_x constituents, and associated ozone reductions, due to these solar proton events (SPEs. The WACCM3 simulations show enhanced short-lived OH and HO₂ concentrations throughout the mesosphere in the 60–82.5° N latitude band due to the SPEs for most days in the 16–21 January 2005 period, somewhat higher in abundance than those observed by the Aura Microwave Limb Sounder (MLS. These HO_x enhancements led to huge predicted and MLS-measured ozone decreases of greater than 40 % throughout most of the northern polar mesosphere during the SPE period. Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS measurements of hydrogen peroxide (H₂O₂ show increases throughout the stratosphere with highest enhancements of about 60 pptv in the lowermost mesosphere over the 16–18 January 2005 period due to the solar protons. WACCM3 predictions indicate H₂O₂ enhancements over the same time period of about three times that amount. Measurements of nitric acid (HNO₃ by both MLS and MIPAS show an increase of about 1 ppbv above background levels in the upper stratosphere during 16–29 January 2005. WACCM3 simulations show only minuscule HNO₃ increases (<0.05 ppbv in the upper stratosphere during this time period. Polar mesospheric enhancements of NO_x are computed to be greater than 50

Safeguarding of large scale reprocessing and MOX plants

International Nuclear Information System (INIS)

Howsley, R.; Burrows, B.; Longevialle, H. de; Kuroi, H.; Izumi, A.

1997-01-01

In May 97, the IAEA Board of Governors approved the final measures of the ''93+2'' safeguards strengthening programme, thus improving the international non-proliferation regime by enhancing the effectiveness and efficiency of safeguards verification. These enhancements are not however, a revolution in current practices, but rather an important step in the continuous evolution of the safeguards system. The principles embodied in 93+2, for broader access to information and increased physical access already apply, in a pragmatic way, to large scale reprocessing and MOX fabrication plants. In these plants, qualitative measures and process monitoring play an important role in addition to accountancy and material balance evaluations in attaining the safeguard's goals. This paper will reflect on the safeguards approaches adopted for these large bulk handling facilities and draw analogies, conclusions and lessons for the forthcoming implementation of the 93+2 Programme. (author)

A puzzle assembly strategy for fabrication of large engineered cartilage tissue constructs.

Science.gov (United States)

Nover, Adam B; Jones, Brian K; Yu, William T; Donovan, Daniel S; Podolnick, Jeremy D; Cook, James L; Ateshian, Gerard A; Hung, Clark T

2016-03-21

Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young׳s modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reinforced dynamics for enhanced sampling in large atomic and molecular systems

Science.gov (United States)

Zhang, Linfeng; Wang, Han; E, Weinan

2018-03-01

A new approach for efficiently exploring the configuration space and computing the free energy of large atomic and molecular systems is proposed, motivated by an analogy with reinforcement learning. There are two major components in this new approach. Like metadynamics, it allows for an efficient exploration of the configuration space by adding an adaptively computed biasing potential to the original dynamics. Like deep reinforcement learning, this biasing potential is trained on the fly using deep neural networks, with data collected judiciously from the exploration and an uncertainty indicator from the neural network model playing the role of the reward function. Parameterization using neural networks makes it feasible to handle cases with a large set of collective variables. This has the potential advantage that selecting precisely the right set of collective variables has now become less critical for capturing the structural transformations of the system. The method is illustrated by studying the full-atom explicit solvent models of alanine dipeptide and tripeptide, as well as the system of a polyalanine-10 molecule with 20 collective variables.

Enhancing a slow and weak optomechanical nonlinearity with delayed quantum feedback

Science.gov (United States)

Wang, Zhaoyou; Safavi-Naeini, Amir H.

2017-07-01

A central goal of quantum optics is to generate large interactions between single photons so that one photon can strongly modify the state of another one. In cavity optomechanics, photons interact with the motional degrees of freedom of an optical resonator, for example, by imparting radiation pressure forces on a movable mirror or sensing minute fluctuations in the position of the mirror. Here, we show that the optical nonlinearity arising from these effects, typically too small to operate on single photons, can be sufficiently enhanced with feedback to generate large interactions between single photons. We propose a protocol that allows photons propagating in a waveguide to interact with each other through multiple bounces off an optomechanical system. The protocol is analysed by evolving the full many-body quantum state of the waveguide-coupled system, illustrating that large photon-photon interactions mediated by mechanical motion may be within experimental reach.

Antenna-assisted enhanced transmission through subwavelength nanoholes

DEFF Research Database (Denmark)

Xiao, Sanshui; Peng, Liang; Mortensen, Asger

2010-01-01

By structural engineering of sub-wavelength apertures, we numerically demonstrate that transmission through apertures can be significantly enhanced. Based on equivalent circuit theory analysis, structured apertures are obtained with a 1900-fold transmission enhancement factor. We show that the en......By structural engineering of sub-wavelength apertures, we numerically demonstrate that transmission through apertures can be significantly enhanced. Based on equivalent circuit theory analysis, structured apertures are obtained with a 1900-fold transmission enhancement factor. We show...

Metal-enhanced fluorescence exciplex emission.

Science.gov (United States)

Zhang, Yongxia; Mali, Buddha L; Geddes, Chris D

2012-01-01

In this letter, we report the first observation of metal-enhanced exciplex fluorescence, observed from anthracene in the presence of diethylaniline. Anthracene in the presence of diethylaniline in close proximity to Silver Island Films (SIFs) shows enhanced monomer and exciplex emission as compared to a non-silvered control sample containing no silver nanoparticles. Our findings suggest two complementary methods for the enhancement: (i) surface plasmons can radiate coupled monomer and exciplex fluorescence efficiently, and (ii) enhanced absorption (enhanced electric near-field) further facilitates enhanced emission. Our exciplex studies help us to further understand the complex photophysics of the metal-enhanced fluorescence technology. Copyright © 2011 Elsevier B.V. All rights reserved.

Eccentric muscle challenge shows osteopontin polymorphism modulation of muscle damage.

Science.gov (United States)

Barfield, Whitney L; Uaesoontrachoon, Kitipong; Wu, Chung-Sheih; Lin, Stephen; Chen, Yue; Wang, Paul C; Kanaan, Yasmine; Bond, Vernon; Hoffman, Eric P

2014-08-01

A promoter polymorphism of the osteopontin (OPN) gene (rs28357094) has been associated with multiple inflammatory states, severity of Duchenne muscular dystrophy (DMD) and muscle size in healthy young adults. We sought to define the mechanism of action of the polymorphism, using allele-specific in vitro reporter assays in muscle cells, and a genotype-stratified intervention in healthy controls. In vitro reporter constructs showed the G allele to respond to estrogen treatment, whereas the T allele showed no transcriptional response. Young adult volunteers (n = 187) were enrolled into a baseline study, and subjects with specific rs28357094 genotypes enrolled into an eccentric muscle challenge intervention [n = 3 TT; n = 3 GG/GT (dominant inheritance model)]. Female volunteers carrying the G allele showed significantly greater inflammation and increased muscle volume change as determined by magnetic resonance imaging T1- and T2-weighted images after eccentric challenge, as well as greater decrement in biceps muscle force. Our data suggest a model where the G allele enables enhanced activities of upstream enhancer elements due to loss of Sp1 binding at the polymorphic site. This results in significantly greater expression of the pro-inflammatory OPN cytokine during tissue remodeling in response to challenge in G allele carriers, promoting muscle hypertrophy in normal females, but increased damage in DMD patients. © The Author 2014. Published by Oxford University Press.

Nanostructured surface enhanced Raman scattering substrates for explosives detection

DEFF Research Database (Denmark)

Schmidt, Michael Stenbaek; Olsen, Jesper Kenneth; Boisen, Anja

2010-01-01

Here we present a method for trace detection of explosives in the gas phase using novel surface enhanced Raman scattering (SERS) spectroscopy substrates. Novel substrates that produce an exceptionally large enhancement of the Raman effect were used to amplify the Raman signal of explosives...

Gas storage carbon with enhanced thermal conductivity

Science.gov (United States)

Burchell, Timothy D.; Rogers, Michael Ray; Judkins, Roddie R.

2000-01-01

A carbon fiber carbon matrix hybrid adsorbent monolith with enhanced thermal conductivity for storing and releasing gas through adsorption and desorption is disclosed. The heat of adsorption of the gas species being adsorbed is sufficiently large to cause hybrid monolith heating during adsorption and hybrid monolith cooling during desorption which significantly reduces the storage capacity of the hybrid monolith, or efficiency and economics of a gas separation process. The extent of this phenomenon depends, to a large extent, on the thermal conductivity of the adsorbent hybrid monolith. This invention is a hybrid version of a carbon fiber monolith, which offers significant enhancements to thermal conductivity and potential for improved gas separation and storage systems.

Enhancement of the Laser Transmission Weldability between Polyethylene and Polyoxymethylene by Plasma Surface Treatment

Directory of Open Access Journals (Sweden)

Huixia Liu

2017-12-01

Full Text Available Due to their large compatibility difference, polyethylene (PE and polyoxymethylene (POM cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM, optical microscopy, and X-ray photoelectron spectroscopy (XPS. Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force.

Contrast-enhanced ultrasound and computed tomography findings of recurrent ovarian steroid cell tumor presenting with peritoneal seeding: A case report

International Nuclear Information System (INIS)

Im, A Lan; Lee, Young Hwan; Kim, Hye Won; Lee, Han Ah; Choi, Keum Ha

2013-01-01

We present ultrasonography and computed tomography (CT) findings of a case of recurrent ovarian steroid cell tumor presenting with peritoneal seeding in a 45-year-old woman. On abdominal ultrasonography, there were multiple hypoechoic round masses in the peritoneal cavity including the perihepatic area. Contrast-enhanced ultrasonography showed intense homogenous enhancement on the arterial phase and delayed prolonged enhancement of the masses. CT revealed multiple peritoneal solid masses with strong enhancement. Five years ago, the patient had been diagnosed with a steroid cell tumor of the left ovary. At that time, the CT showed a well-enhancing, lobulating, large solid mass at the left adnexa. Imaging findings of the peritoneal masses suggested peritoneal seeding from the preexisting ovarian steroid cell tumor. For treatment of the metastatic lesions in the perihepatic area, ultrasonography-guided radiofrequency ablation (RFA) was performed, and debulking surgery for the peritoneal masses was done. Six months later, complete ablation of the perihepatic metastases by RFA and a marked decrease in the peritoneal metastases by surgery were found on the follow-up CT.

Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas

International Nuclear Information System (INIS)

Fromm, David P.; Sundaramurthy, Arvind; Kinkhabwala, Anika; Schuck, P. James; Kino, Gordon S.; Moerner, W.E.

2006-01-01

Single metallic bowtie nanoantennas provide a controllable environment for surface-enhanced Raman scattering (SERS) of adsorbed molecules. Bowties have experimentally measured electromagnetic enhancements, enabling estimation of chemical enhancement for both the bulk and the few-molecule regime. Strong fluctuations of selected Raman lines imply that a small number of p-mercaptoaniline molecules on a single bowtie show chemical enhancement >10 7 , much larger than previously believed, likely due to charge transfer between the Au surface and the molecule. This chemical sensitivity of SERS has significant implications for ultra-sensitive detection of single molecules

Large-scale genomic analysis shows association between homoplastic genetic variation in Mycobacterium tuberculosis genes and meningeal or pulmonary tuberculosis.

NARCIS (Netherlands)

Ruesen, Carolien; Chaidir, Lidya; van Laarhoven, Arjan; Dian, Sofiati; Ganiem, Ahmad Rizal; Nebenzahl-Guimaraes, Hanna; Huynen, Martijn A; Alisjahbana, Bachti; Dutilh, Bas E; van Crevel, Reinout

2018-01-01

Meningitis is the most severe manifestation of tuberculosis. It is largely unknown why some people develop pulmonary TB (PTB) and others TB meningitis (TBM); we examined if the genetic background of infecting M. tuberculosis strains may be relevant.

Theory of super-para-electric large polaron for gigantic photo-enhancements of dielectric constant and electronic conductivity in SrTiO3

International Nuclear Information System (INIS)

Yu Qiu; Nasu, Keiichiro

2005-01-01

In connection with the recent experimental discoveries on gigantic photoenhancements of the electronic conductivity and the quasi-static dielectric susceptibility in SrTiO 3 , we theoretically study a photo-generation mechanism of a charged ferroelectric domain in this quantum dielectric. The photo-generated electron, being quite itinerant in the 3d band of Ti 4+ , is assumed to couple weakly but quadratically with soft-anharmonic T 1u phonons in this quantum dielectric. The photo-generated electron is also assumed to couple strongly but linearly with the breathing type high energy phonons. Using a tight binding model for electron, we will show that these two types of electron-phonon couplings result in two types of polarons, a 'super-para-electric (SPE) large polaron' with a quasi-global parity violation, and an 'off-centre type self-trapped polaron' with only a local parity violation. We will also show that this SPE large polaron is nothing else but a singly charged (e - ) and conductive ferroelectric (or SPE) domain with a quasi macroscopic size. This polaron or domain is also shown to have a high mobility and a large quasi-static dielectric susceptibility

Gate-tunable large magnetoresistance in an all-semiconductor spin valve device.

Science.gov (United States)

Oltscher, M; Eberle, F; Kuczmik, T; Bayer, A; Schuh, D; Bougeard, D; Ciorga, M; Weiss, D

2017-11-27

A large spin-dependent and electric field-tunable magnetoresistance of a two-dimensional electron system is a key ingredient for the realization of many novel concepts for spin-based electronic devices. The low magnetoresistance observed during the last few decades in devices with lateral semiconducting transport channels between ferromagnetic source and drain contacts has been the main obstacle for realizing spin field effect transistor proposals. Here, we show both a large two-terminal magnetoresistance in a lateral spin valve device with a two-dimensional channel, with up to 80% resistance change, and tunability of the magnetoresistance by an electric gate. The enhanced magnetoresistance is due to finite electric field effects at the contact interface, which boost spin-to-charge conversion. The gating scheme that we use is based on switching between uni- and bidirectional spin diffusion, without resorting to spin-orbit coupling. Therefore, it can also be employed in materials with low spin-orbit coupling.

Numerical Investigation on Absorption Enhancement of Black Carbon Aerosols Partially Coated With Nonabsorbing Organics

Science.gov (United States)

Zhang, Xiaolin; Mao, Mao; Yin, Yan; Wang, Bin

2018-01-01

This study numerically evaluates the effects of aerosol microphysics, including coated volume fraction of black carbon (BC), shell/core ratio, and size distribution, on the absorption enhancement (Eab) of polydisperse BC aggregates partially coated by organics, which is calculated by the exact multiple-sphere T-matrix method. The coated volume fraction of BC plays a substantial role in determining the absorption enhancement of partially coated BC aggregates, which typically have an Eab in the range of 1.0-2.0 with a larger value for larger coated volume fraction of BC as the shell/core ratio, BC geometry, and size distribution are fixed. The shell/core ratio, BC geometry, and size distribution have little impact on the Eab of coated BC with small coated volume fraction of BC, while they become significant for large coated volume fraction of BC. The Eab of partially coated BC particles can be slightly less than 1.0 for the large BC in the accumulation mode exhibiting large shell/core ratio and small coated volume fraction of BC, indicating that the absorption shows even slight decrease relative to uncoated BC particles. For partially coated BC aggregates in the accumulation and coarse modes, the refractive index uncertainties of BC result in the Eab differences of less than 9% and 2%, respectively, while those of organics can induce larger variations with the maximum differences up to 22% and 18%, respectively. Our study indicates that accounting for particle coating microphysics, particularly the coated volume fraction of BC, can potentially help to understand the differences in observations of largely variable absorption enhancements over various regions.

Jets from jets: re-clustering as a tool for large radius jet reconstruction and grooming at the LHC

Energy Technology Data Exchange (ETDEWEB)

Nachman, Benjamin; Nef, Pascal; Schwartzman, Ariel; Swiatlowski, Maximilian [SLAC National Accelerator Laboratory, Stanford University,2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Wanotayaroj, Chaowaroj [Center for High Energy Physics, University of Oregon,1371 E. 13th Ave, Eugene, OR 97403 (United States)

2015-02-12

Jets with a large radius R≳1 and grooming algorithms are widely used to fully capture the decay products of boosted heavy particles at the Large Hadron Collider (LHC). Unlike most discriminating variables used in such studies, the jet radius is usually not optimized for specific physics scenarios. This is because every jet configuration must be calibrated, insitu, to account for detector response and other experimental effects. One solution to enhance the availability of large-R jet configurations used by the LHC experiments is jet re-clustering. Jet re-clustering introduces an intermediate scale rlarge radius jets. In this paper we systematically study and propose new jet re-clustering configurations and show that re-clustered large radius jets have essentially the same jet mass performance as large radius groomed jets. Jet re-clustering has the benefit that no additional large-R calibration is necessary, allowing the re-clustered large radius parameter to be optimized in the context of specific precision measurements or searches for new physics.

Jets from jets: re-clustering as a tool for large radius jet reconstruction and grooming at the LHC

International Nuclear Information System (INIS)

Nachman, Benjamin; Nef, Pascal; Schwartzman, Ariel; Swiatlowski, Maximilian; Wanotayaroj, Chaowaroj

2015-01-01

Jets with a large radius R≳1 and grooming algorithms are widely used to fully capture the decay products of boosted heavy particles at the Large Hadron Collider (LHC). Unlike most discriminating variables used in such studies, the jet radius is usually not optimized for specific physics scenarios. This is because every jet configuration must be calibrated, insitu, to account for detector response and other experimental effects. One solution to enhance the availability of large-R jet configurations used by the LHC experiments is jet re-clustering. Jet re-clustering introduces an intermediate scale rlarge radius jets. In this paper we systematically study and propose new jet re-clustering configurations and show that re-clustered large radius jets have essentially the same jet mass performance as large radius groomed jets. Jet re-clustering has the benefit that no additional large-R calibration is necessary, allowing the re-clustered large radius parameter to be optimized in the context of specific precision measurements or searches for new physics.

Fabrication of large area plasmonic nanoparticle grating structure on silver halide based transmission electron microscope film and its application as a surface enhanced Raman spectroscopy substrate

International Nuclear Information System (INIS)

Sudheer,; Tiwari, P.; Singh, M. N.; Sinha, A. K.; Rai, V. N.; Srivastava, A. K.; Bhartiya, S.; Mukherjee, C.

2015-01-01

The plasmonic responses of silver nanoparticle grating structures of different periods made on silver halide based electron microscope film are investigated. Raster scan of the conventional scanning electron microscope (SEM) is used to carry out electron beam lithography for fabricating the plasmonic nanoparticle grating (PNG) structures. Morphological characterization of the PNG structures, carried out by the SEM and the atomic force microscope, indicates that the depth of the groove decreases with a decrease in the grating period. Elemental characterization performed by the energy dispersive spectroscopy and the x-ray diffraction shows the presence of nanoparticles of silver in the PNG grating. The optical characterization of the gratings shows that the localized surface plasmon resonance peak shifts from 366 to 378 nm and broadens with a decrease in grating period from 10 to 2.5 μm. The surface enhanced Raman spectroscopy of the Rhodamine-6G dye coated PNG structure shows the maximum enhancement by two orders of magnitude in comparison to the randomly distributed silver nanoparticles having similar size and shape as the PNG structure

Large spin relaxation anisotropy and valley-Zeeman spin-orbit coupling in WSe2/graphene/h -BN heterostructures

Science.gov (United States)

Zihlmann, Simon; Cummings, Aron W.; Garcia, Jose H.; Kedves, Máté; Watanabe, Kenji; Taniguchi, Takashi; Schönenberger, Christian; Makk, Péter

2018-02-01

Large spin-orbital proximity effects have been predicted in graphene interfaced with a transition-metal dichalcogenide layer. Whereas clear evidence for an enhanced spin-orbit coupling has been found at large carrier densities, the type of spin-orbit coupling and its relaxation mechanism remained unknown. We show an increased spin-orbit coupling close to the charge neutrality point in graphene, where topological states are expected to appear. Single-layer graphene encapsulated between the transition-metal dichalcogenide WSe2 and h -BN is found to exhibit exceptional quality with mobilities as high as 1 ×105 cm2 V-1 s-1. At the same time clear weak antilocalization indicates strong spin-orbit coupling, and a large spin relaxation anisotropy due to the presence of a dominating symmetric spin-orbit coupling is found. Doping-dependent measurements show that the spin relaxation of the in-plane spins is largely dominated by a valley-Zeeman spin-orbit coupling and that the intrinsic spin-orbit coupling plays a minor role in spin relaxation. The strong spin-valley coupling opens new possibilities in exploring spin and valley degree of freedom in graphene with the realization of new concepts in spin manipulation.

Coarse cluster enhancing collaborative recommendation for social network systems

Science.gov (United States)

Zhao, Yao-Dong; Cai, Shi-Min; Tang, Ming; Shang, Min-Sheng

2017-10-01

Traditional collaborative filtering based recommender systems for social network systems bring very high demands on time complexity due to computing similarities of all pairs of users via resource usages and annotation actions, which thus strongly suppresses recommending speed. In this paper, to overcome this drawback, we propose a novel approach, namely coarse cluster that partitions similar users and associated items at a high speed to enhance user-based collaborative filtering, and then develop a fast collaborative user model for the social tagging systems. The experimental results based on Delicious dataset show that the proposed model is able to dramatically reduce the processing time cost greater than 90 % and relatively improve the accuracy in comparison with the ordinary user-based collaborative filtering, and is robust for the initial parameter. Most importantly, the proposed model can be conveniently extended by introducing more users' information (e.g., profiles) and practically applied for the large-scale social network systems to enhance the recommending speed without accuracy loss.

Five Performance Enhancements for Hybrid Hash Join

National Research Council Canada - National Science Library

Graefe, Goetz

1992-01-01

.... We discuss five performance enhancements for hybrid hash join algorithms, namely data compression, large cluster sizes and multi-level recursion, role reversal of build and probe inputs, histogram...

Enhanced ion acoustic fluctuations and ion outflows

Directory of Open Access Journals (Sweden)

F. R. E. Forme

1999-02-01

Full Text Available A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acoustic lines. This spectral asymmetry and the intensity of the received signal cannot be resolved by the standard analysis procedure and often causes its failure. As a result, and in spite of a very clear spectral signature, the analysis is unable to fit the plasma parameters inside the regions of ion acoustic turbulence. We present European Incoherent Scatter radar (EISCAT observations of large ion outflows associated with the simultaneous occurrence of enhanced ion acoustic echoes. The ion fluxes can reach 1014 m-2 s-1 at 800 km altitude. From the very clear spectral signatures of these echoes, a method is presented to extract estimates of the electron temperature and the ion drift within the turbulent regions. It is shown that the electron gas is strongly heated up to 11 000 K. Also electron temperature gradients of about 0.02 K/m exist. Finally, the estimates of the electron temperature and of the ion drift are used to study the possible implications for the plasma transport inside turbulent regions. It is shown that strong electron temperature gradients cause enhancement of the ambipolar electric field and can account for the observed ion outflows.Key words. Ionosphere (auroral ionosphere; ionosphere · magnetosphere interactions; plasma waves and instabilities.

Sequential contrast-enhanced MR imaging of the penis.

Science.gov (United States)

Kaneko, K; De Mouy, E H; Lee, B E

1994-04-01

To determine the enhancement patterns of the penis at magnetic resonance (MR) imaging. Sequential contrast material-enhanced MR images of the penis in a flaccid state were obtained in 16 volunteers (12 with normal penile function and four with erectile dysfunction). Subjects with normal erectile function showed gradual and centrifugal enhancement of the corpora cavernosa, while those with erectile dysfunction showed poor enhancement with abnormal progression. Sequential contrast-enhanced MR imaging provides additional morphologic information for the evaluation of erectile dysfunction.

The origin of enhanced optical absorption in solar cells with metal nanoparticles embedded in the active layer

KAUST Repository

Lee, Jung-Yong

2010-04-29

We analyze the enhancement in optical absorption of an absorbing medium when spherical metal nanoparticles are embedded in it. Our analysis uses generalized Mie theory to calculate the absorbed optical power as a function of the distance from the metal nanoparticle. This analysis is used to evaluate the potential of enhancing optical absorption in thin-film solar cells by embedding spherical metal nanoparticles. We consider the trade-off between maximizing overall optical absorption and ensuring that a large fraction of the incident optical power is dissipated in the absorbing host medium rather than in the metal nanoparticle. We show that enhanced optical absorption results from strong scattering by the metal nanoparticle which locally enhances the optical electric fields. We also discuss the effect of a thin dielectric encapsulation of the metal nanoparticles. ©2010 Optical Society of America.

The origin of enhanced optical absorption in solar cells with metal nanoparticles embedded in the active layer

KAUST Repository

Lee, Jung-Yong; Peumans, Peter

2010-01-01

We analyze the enhancement in optical absorption of an absorbing medium when spherical metal nanoparticles are embedded in it. Our analysis uses generalized Mie theory to calculate the absorbed optical power as a function of the distance from the metal nanoparticle. This analysis is used to evaluate the potential of enhancing optical absorption in thin-film solar cells by embedding spherical metal nanoparticles. We consider the trade-off between maximizing overall optical absorption and ensuring that a large fraction of the incident optical power is dissipated in the absorbing host medium rather than in the metal nanoparticle. We show that enhanced optical absorption results from strong scattering by the metal nanoparticle which locally enhances the optical electric fields. We also discuss the effect of a thin dielectric encapsulation of the metal nanoparticles. ©2010 Optical Society of America.

ITO films with enhanced electrical properties deposited on unheated ZnO-coated polymer substrates

International Nuclear Information System (INIS)

Nunes de Carvalho, C.; Lavareda, G.; Fortunato, E.; Alves, H.; Goncalves, A.; Varela, J.; Nascimento, R.; Amaral, A.

2005-01-01

Indium tin oxide (ITO) films were deposited by radio frequency (rf)-plasma enhanced reactive thermal evaporation (rf-PERTE) at room temperature on intrinsic ZnO/polymer substrates to enhance their electrical and structural properties. The polymer substrate used is polyethylene terephthalate (PET). The thickness of the ZnO films varied in the range 50-150 nm. The average thickness of the ITO films is of about 170 nm. Results show that ITO deposited on bare PET substrates exhibit: an average visible transmittance of about 85% and an electrical resistivity of 5.6 x 10 -2 Ω cm. ITO on ZnO/PET substrates show the optical quality practically preserved and the resistivity decreased to a minimum value of 1.9x10 -3 Ω cm for ZnO layers 125 nm thick. The electrical properties of ITO on ZnO/PET are largely improved by the increase in carrier mobility

WCK 5107 (Zidebactam) and WCK 5153 Are Novel Inhibitors of PBP2 Showing Potent "β-Lactam Enhancer" Activity against Pseudomonas aeruginosa, Including Multidrug-Resistant Metallo-β-Lactamase-Producing High-Risk Clones.

Science.gov (United States)

Moya, Bartolome; Barcelo, Isabel M; Bhagwat, Sachin; Patel, Mahesh; Bou, German; Papp-Wallace, Krisztina M; Bonomo, Robert A; Oliver, Antonio

2017-06-01

Zidebactam and WCK 5153 are novel β-lactam enhancers that are bicyclo-acyl hydrazides (BCH), derivatives of the diazabicyclooctane (DBO) scaffold, targeted for the treatment of serious infections caused by highly drug-resistant Gram-negative pathogens. In this study, we determined the penicillin-binding protein (PBP) inhibition profiles and the antimicrobial activities of zidebactam and WCK 5153 against Pseudomonas aeruginosa , including multidrug-resistant (MDR) metallo-β-lactamase (MBL)-producing high-risk clones. MIC determinations and time-kill assays were conducted for zidebactam, WCK 5153, and antipseudomonal β-lactams using wild-type PAO1, MexAB-OprM-hyperproducing ( mexR ), porin-deficient ( oprD ), and AmpC-hyperproducing ( dacB ) derivatives of PAO1, and MBL-expressing clinical strains ST175 ( bla VIM-2 ) and ST111 ( bla VIM-1 ). Furthermore, steady-state kinetics was used to assess the inhibitory potential of these compounds against the purified VIM-2 MBL. Zidebactam and WCK 5153 showed specific PBP2 inhibition and did not inhibit VIM-2 (apparent K i [ K i app ] > 100 μM). MICs for zidebactam and WCK 5153 ranged from 2 to 32 μg/ml (amdinocillin MICs > 32 μg/ml). Time-kill assays revealed bactericidal activity of zidebactam and WCK 5153. LIVE-DEAD staining further supported the bactericidal activity of both compounds, showing spheroplast formation. Fixed concentrations (4 or 8 μg/ml) of zidebactam and WCK 5153 restored susceptibility to all of the tested β-lactams for each of the P. aeruginosa mutant strains. Likewise, antipseudomonal β-lactams (CLSI breakpoints), in combination with 4 or 8 μg/ml of zidebactam or WCK 5153, resulted in enhanced killing. Certain combinations determined full bacterial eradication, even with MDR MBL-producing high-risk clones. β-Lactam-WCK enhancer combinations represent a promising β-lactam "enhancer-based" approach to treat MDR P. aeruginosa infections, bypassing the need for MBL inhibition. Copyright © 2017

Designing Nordic Technology-Enhanced Learning

Science.gov (United States)

Cerratto-Pargman, Teresa; Jarvela, Sanna M.; Milrad, Marcelo

2012-01-01

The latest developments of information and communication technologies (ICT) and its large penetration in different sectors of our society pose new challenges and demands in the field of education. This special issue entitled "Designing Nordic technology-enhanced learning (TEL)", presents and discusses how researchers in the Nordic…

The perils of moral enhancement

Directory of Open Access Journals (Sweden)

Dobrijević Aleksandar

2012-01-01

Full Text Available The idea of biotechnological enhancement of people for non-medical purposes is not unambiguous. A gap that may arise between the “cognitive” and so-called “moral” enhancement points precisely to this fact. This article shows that, contrary to the intentions of its supporters, the idea according to which moral enhancement has precedence over cognitive enhancement is essentially just a new form of undermining human freedom. [Projekat Ministarstva nauke Republike Srbije, br. 41004

Making Cooperation Work: Generalized Social Trust and Large-N Collective Action

DEFF Research Database (Denmark)

Sønderskov, Kim Mannemar

It has often been argued that generalized social trust, the belief that most people are trustworthy, enhances cooperation in large-N collective action dilemmas. Large-N dilemmas are situations where an actor has to decide whether to contribute to the provision of public goods that benefit a large...... number of people. Modern societies abound with such dilemmas, and if generalized social trust does enhance voluntary contributions it would be a very valuable asset that would benefit every society. This dissertation digs into this frequently posited relationship. A series of empirical analyses drawing...... on survey and national level data from several countries is used to investigate if, how, and when generalized social trust leads to collective action. Specifically, citizens' behavior in relation to the environment is used as the indicator of voluntary public good provision. This indicator affords excellent...

Large Eddy simulations of jet in cross flow; Simulations aux grandes echelles: application au jet transverse

Energy Technology Data Exchange (ETDEWEB)

Priere, C

2005-01-15

Nowadays, environmental and economic constraints require considerable research efforts from the gas turbine industry. Objectives aim at lowering pollutants emissions and fuel consumption. These efforts take a primary importance to satisfy a continue growth of energy production and to obey to stringent environmental legislations. Recorded progresses are linked to mixing enhancement in combustors running at lean premixed operating point. Indeed, industry shows itself to be attentive in the mixing enhancement and during the last years, efforts are concentrated on fresh and burned gas dilution. The Jet In Cross Flow (JICF), which constitutes a representative case to further the research effort. It has been to be widely studied both in experimentally and numerically, and is particularly well suited for the evaluation of Large Eddy Simulations (LES). This approach, where large scale phenomena are naturally taken into account in the governing equation while the small scales are modelled, offers the means to well-predict such flows. The main objective of this work is to gauge and to enhance the quality of the LES predictions in JICF configurations by means of numerical tools developed in the compressible AVBP code. Physical and numerical parameters considered in the JICF modelization are taken into account and strategies that are able to enhance quality of LES results are proposed. Configurations studied in this work are the following: - Influences of the boundary conditions and jet injection system on a free JICF - Study of static mixing device in an industrial gas turbine chamber. - Study of a JICF configuration represented a dilution zone in low emissions combustors. (author)

Resistance transition assisted geometry enhanced magnetoresistance in semiconductors

International Nuclear Information System (INIS)

Luo, Zhaochu; Zhang, Xiaozhong

2015-01-01

Magnetoresistance (MR) reported in some non-magnetic semiconductors (particularly silicon) has triggered considerable interest owing to the large magnitude of the effect. Here, we showed that MR in lightly doped n-Si can be significantly enhanced by introducing two diodes and proper design of the carrier path [Wan, Nature 477, 304 (2011)]. We designed a geometrical enhanced magnetoresistance (GEMR) device whose room-temperature MR ratio reaching 30% at 0.065 T and 20 000% at 1.2 T, respectively, approaching the performance of commercial MR devices. The mechanism of this GEMR is: the diodes help to define a high resistive state (HRS) and a low resistive state (LRS) in device by their openness and closeness, respectively. The ratio of apparent resistance between HRS and LRS is determined by geometry of silicon wafer and electrodes. Magnetic field could induce a transition from LRS to HRS by reshaping potential and current distribution among silicon wafer, resulting in a giant enhancement of intrinsic MR. We expect that this GEMR could be also realized in other semiconductors. The combination of high sensitivity to low magnetic fields and large high-field response should make this device concept attractive to the magnetic field sensing industry. Moreover, because this MR device is based on a conventional silicon/semiconductor platform, it should be possible to integrate this MR device with existing silicon/semiconductor devices and so aid the development of silicon/semiconductor-based magnetoelectronics. Also combining MR devices and semiconducting devices in a single Si/semiconductor chip may lead to some novel devices with hybrid function, such as electric-magnetic-photonic properties. Our work demonstrates that the charge property of semiconductor can be used in the magnetic sensing industry, where the spin properties of magnetic materials play a role traditionally

Stability Enhancement of a Power System Containing High-Penetration Intermittent Renewable Generation

Directory of Open Access Journals (Sweden)

Jorge Morel

2015-06-01

Full Text Available This paper considers the transient stability enhancement of a power system containing large amounts of solar and wind generation in Japan. Following the Fukushima Daiichi nuclear disaster there has been an increasing awareness on the importance of a distributed architecture, based mainly on renewable generation, for the Japanese power system. Also, the targets of CO2 emissions can now be approached without heavily depending on nuclear generation. Large amounts of renewable generation leads to a reduction in the total inertia of the system because renewable generators are connected to the grid by power converters, and transient stability becomes a significant issue. Simulation results show that sodium-sulfur batteries can keep the system in operation and stable after strong transient disturbances, especially for an isolated system. The results also show how the reduction of the inertia in the system can be mitigated by exploiting the kinetic energy of wind turbines.

Optimizing silver-capped silicon nanopillars to simultaneously realize macroscopic, practical-level SERS signal reproducibility and high enhancement at low costs

DEFF Research Database (Denmark)

Wu, Kaiyu; Rindzevicius, Tomas; Schmidt, Michael Stenbæk

2017-01-01

and show that the improved structures exhibit unrivalled macroscale SERS uniformities (RSD: ∼2.5% in millimeter scale, ∼7% in wafer scale) and reproducibility (RSD: ∼1.5% across 3 wafers), while at the same time exhibiting a very large average SERS enhancement factor of >108. The obtained SERS uniformity...

Fabrication of large area nanoprism arrays and their application for surface enhanced Raman spectroscopy

International Nuclear Information System (INIS)

Cui, B; Clime, L; Li, K; Veres, T

2008-01-01

This work demonstrates the fabrication of metallic nanoprism (triangular nanostructure) arrays using a low-cost and high-throughput process. In the method, the triangular structure is defined by the shadow of a pyramid during angle evaporation of a metal etching mask. The pyramids were created by nanoimprint lithography in polymethylmethacrylate (PMMA) using a mould having an inverse-pyramid-shaped hole array formed by KOH wet etching of silicon. Silver and gold nanoprism arrays with a period of 200 nm and an edge length of 100 nm have been fabricated and used as effective substrates for surface enhanced Raman spectroscopy (SERS) detection of rhodamine 6G (R6G) molecules. Numerical calculations confirmed the great enhancement of electric field near the sharp nanoprism corners, as well as the detrimental effect of the chromium adhesion layer on localized surface plasmon resonance. The current method can also be used to fabricate non-equilateral nanoprism and three-dimensional (3D) nanopyramid arrays, and it can be readily extended to other metals

Analysis of ring enhancement in the cranial computed tomography

Energy Technology Data Exchange (ETDEWEB)

Huh, Seung Jae; Chung, Yong In; Chang, Kee Hyun [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

1980-12-15

A total of 83 cases with ring enhancement in the cranial computed tomography were radiologically analyzed to determine the specific CT findings of the primary and metastatic brain tumor, inflammatory disease, resolving hematoma, and cerebral infarction. The brief results are as follows. Glioblastoma multiform show a characteristic thick or thin irregular ring enhancement with significant mass effect and surrounding edema. Most of the metastatic tumors also show irregular thick or thin walled ring enhancement with significant surrounding edema. Tumoral hemorrhage was observed in the metastatic melanoma, breast cancer, and lung cancer. The brain abscess usually show characteristic thin regular and smooth ring enhancement with moderate peripheral edema. The parasitic cysts also show thin regular ring enhancement with different degree of surrounding edema. Ring enhancement in resolving hematomas and cerebral infarctions usually occurs about 10-30 days after the onset of symptoms, which shows thin and regular ring pattern without significant surrounding edema.

Analysis of ring enhancement in the cranial computed tomography

International Nuclear Information System (INIS)

Huh, Seung Jae; Chung, Yong In; Chang, Kee Hyun

1980-01-01

A total of 83 cases with ring enhancement in the cranial computed tomography were radiologically analyzed to determine the specific CT findings of the primary and metastatic brain tumor, inflammatory disease, resolving hematoma, and cerebral infarction. The brief results are as follows. Glioblastoma multiform show a characteristic thick or thin irregular ring enhancement with significant mass effect and surrounding edema. Most of the metastatic tumors also show irregular thick or thin walled ring enhancement with significant surrounding edema. Tumoral hemorrhage was observed in the metastatic melanoma, breast cancer, and lung cancer. The brain abscess usually show characteristic thin regular and smooth ring enhancement with moderate peripheral edema. The parasitic cysts also show thin regular ring enhancement with different degree of surrounding edema. Ring enhancement in resolving hematomas and cerebral infarctions usually occurs about 10-30 days after the onset of symptoms, which shows thin and regular ring pattern without significant surrounding edema

Optically enhanced nuclear cross polarization in acridine-doped fluorene

Energy Technology Data Exchange (ETDEWEB)

Oshiro, C.M.

1982-06-01

The objective of this work has been to create large polarizations of the dilute /sup 13/C nuclei in the solid state. The idea was to create /sup 1/H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the /sup 13/C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large /sup 1/H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large /sup 13/C polarizations have been created in fluorene single crystals. These large /sup 13/C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined.

Optically enhanced nuclear cross polarization in acridine-doped fluorene

International Nuclear Information System (INIS)

Oshiro, C.M.

1982-06-01

The objective of this work has been to create large polarizations of the dilute 13 C nuclei in the solid state. The idea was to create 1 H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the 13 C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large 1 H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large 13 C polarizations have been created in fluorene single crystals. These large 13 C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined

Large thermoelectric efficiency of doped polythiophene junction: A density functional study

Science.gov (United States)

Golsanamlou, Zahra; Bagheri Tagani, Meysam; Rahimpour Soleimani, Hamid

2018-06-01

The thermoelectric properties of polythiophene (PT) coupled to the Au (111) electrodes are studied based on density functional theory with nonequilibrium Green function formalism. Specially, the effect of Li and Cl adsorbents on the thermoelectric efficiency of the PT junction is investigated in different concentrations of the dopants for two lengths of the PT. Results show that the presence of dopants can bring the structural changes in the oligomer and modify the arrangement of the molecular levels leading to the dramatic changes in the transmission spectra of the junction. Therefore, the large enhancement in thermopower and consequently figure of merit is obtained by dopants which makes the doped PT junction as a beneficial thermoelectric device.

Mice Overexpressing Type 1 Adenylyl Cyclase Show Enhanced Spatial Memory Flexibility in the Absence of Intact Synaptic Long-Term Depression

Science.gov (United States)

Zhang, Ming; Wang, Hongbing

2013-01-01

There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca[superscript 2+]-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated…

Fabrication of large area flexible nanoplasmonic templates with flow coating

Science.gov (United States)

Huang, Qian; Devetter, Brent M.; Roosendaal, Timothy; LaBerge, Max; Bernacki, Bruce E.; Alvine, Kyle J.

2017-07-01

We describe the development of a custom-built two-axis flow coater for the deposition of polymeric nanosphere monolayers that could be used in the fabrication of large area nanoplasmonic films. The technique described here has the capability of depositing large areas (up to 7 in. × 10 in.) of self-assembled monolayers of polymeric nanospheres onto polyethylene terephthalate (PET) films. Here, three sets of films consisting of different diameters (ranging from 100 to 300 nm) of polymeric nanospheres were used to demonstrate the capabilities of this instrument. To improve the surface wettability of the PET substrates during wet-deposition, we enhanced the wettability by using a forced air blown-arc plasma treatment system. Both the local microstructure, as confirmed by scanning electron microscopy, describing monolayer and multilayer coverage, and the overall macroscopic uniformity of the resultant nanostructured film were optimized by controlling the relative stage to blade speed and nanosphere concentration. We also show using a smaller nanoparticle template that such monolayers can be used to form nanoplasmonic films. As this flow-coating approach is a scalable technique, large area films such as the ones described here have a variety of crucial emerging applications in areas such as energy, catalysis, and chemical sensing.

Illumina MiSeq Phylogenetic Amplicon Sequencing Shows a Large Reduction of an Uncharacterised Succinivibrionaceae and an Increase of the Methanobrevibacter gottschalkii Clade in Feed Restricted Cattle.

Directory of Open Access Journals (Sweden)

Matthew Sean McCabe

Full Text Available Periodic feed restriction is used in cattle production to reduce feed costs. When normal feed levels are resumed, cattle catch up to a normal weight by an acceleration of normal growth rate, known as compensatory growth, which is not yet fully understood. Illumina Miseq Phylogenetic marker amplicon sequencing of DNA extracted from rumen contents of 55 bulls showed that restriction of feed (70% concentrate, 30% grass silage for 125 days, to levels that caused a 60% reduction of growth rate, resulted in a large increase of relative abundance of Methanobrevibacter gottschalkii clade (designated as OTU-M7, and a large reduction of an uncharacterised Succinivibrionaceae species (designated as OTU-S3004. There was a strong negative Spearman correlation (ρ = -0.72, P = <1x10(-20 between relative abundances of OTU-3004 and OTU-M7 in the liquid rumen fraction. There was also a significant increase in acetate:propionate ratio (A:P in feed restricted animals that showed a negative Spearman correlation (ρ = -0.69, P = <1x10(-20 with the relative abundance of OTU-S3004 in the rumen liquid fraction but not the solid fraction, and a strong positive Spearman correlation with OTU-M7 in the rumen liquid (ρ = 0.74, P = <1x10(-20 and solid (ρ = 0.69, P = <1x10(-20 fractions. Reduced A:P ratios in the rumen are associated with increased feed efficiency and reduced production of methane which has a global warming potential (GWP 100 years of 28. Succinivibrionaceae growth in the rumen was previously suggested to reduce methane emissions as some members of this family utilise hydrogen, which is also utilised by methanogens for methanogenesis, to generate succinate which is converted to propionate. Relative abundance of OTU-S3004 showed a positive Spearman correlation with propionate (ρ = 0.41, P = <0.01 but not acetate in the liquid rumen fraction.

Enhanced localized fluorescence in plasmonic nanoantennae

DEFF Research Database (Denmark)

Bakker, R.M.; Yuan, H.-K.; Liu, Z.

2008-01-01

in fluorescence that reaches 100 times enhancement. Near-field excitation shows enhanced fluorescence from a single nanoantenna localized in a subwavelength area of similar to 0.15 mu m(2). The polarization of enhanced emission is along the main antenna axis. These observed experimental results are important...

A saturation hypothesis to explain both enhanced and impaired learning with enhanced plasticity

Science.gov (United States)

Nguyen-Vu, TD Barbara; Zhao, Grace Q; Lahiri, Subhaneil; Kimpo, Rhea R; Lee, Hanmi; Ganguli, Surya; Shatz, Carla J; Raymond, Jennifer L

2017-01-01

Across many studies, animals with enhanced synaptic plasticity exhibit either enhanced or impaired learning, raising a conceptual puzzle: how enhanced plasticity can yield opposite learning outcomes? Here, we show that the recent history of experience can determine whether mice with enhanced plasticity exhibit enhanced or impaired learning in response to the same training. Mice with enhanced cerebellar LTD, due to double knockout (DKO) of MHCI H2-Kb/H2-Db (KbDb−/−), exhibited oculomotor learning deficits. However, the same mice exhibited enhanced learning after appropriate pre-training. Theoretical analysis revealed that synapses with history-dependent learning rules could recapitulate the data, and suggested that saturation may be a key factor limiting the ability of enhanced plasticity to enhance learning. Optogenetic stimulation designed to saturate LTD produced the same impairment in WT as observed in DKO mice. Overall, our results suggest that the recent history of activity and the threshold for synaptic plasticity conspire to effect divergent learning outcomes. DOI: http://dx.doi.org/10.7554/eLife.20147.001 PMID:28234229

A universal formula for the field enhancement factor

Science.gov (United States)

Biswas, Debabrata

2018-04-01

The field enhancement factor (FEF) is an important quantity in field emission calculations since the tunneling electron current depends very sensitively on its magnitude. The exact dependence of FEF on the emitter height h, the radius of curvature at the apex Ra, as well as the shape of the emitter base are still largely unknown. In this work, a universal formula for the field enhancement factor is derived for a single emitter. It depends on the ratio h/Ra and has the form γ a = ( 2 h / R a ) / [ α 1 ln ( 4 h / R a ) - α 2 ] , where α1 and α2 depend on the charge distribution on the emitter. Numerical results show that a simpler form γ a = ( 2 h / R a ) / [ ln ( 4 h / R a ) - α ] is equally valid with α depending on the emitter-base. Thus, for the hyperboloid, conical, and ellipsoid emitters, the value of α is 0, 0.88, and 2, while for the cylindrical base, α ≃ 2.6.

Neuromyelitis optica with linear enhancement of corpus callosum in brain magnetic resonance imaging with contrast: a case report.

Science.gov (United States)

Sahraian, Mohammad Ali; Moghadasi, Abdorreza Naser; Owji, Mahsa; Naghshineh, Hoda; Minagar, Alireza

2015-06-10

Neuromyelitis optica is a demyelinating disease of the central nervous system with various patterns of brain lesions. Corpus callosum may be involved in both multiple sclerosis and neuromyelitis optica. Previous case reports have demonstrated that callosal lesions in neuromyelitis optica are usually large and edematous and have a heterogeneous intensity showing a "marbled pattern" in the acute phase. Their size and intensity may reduce with time or disappear in the chronic stages. In this report, we describe a case of a 25-year-old Caucasian man with neuromyelitis optica who presented clinically with optic neuritis and myelitis. His brain magnetic resonance imaging demonstrated linear enhancement of the corpus callosum. Brain images with contrast agent added also showed linear ependymal layer enhancement of the lateral ventricles, which has been reported in this disease previously. Linear enhancement of corpus callosum in magnetic resonance imaging with contrast agent could help in diagnosing neuromyelitis optica and differentiating it from other demyelinating disease, especially multiple sclerosis.

Hoxa2 Selectively Enhances Meis Binding to Change a Branchial Arch Ground State

Science.gov (United States)

Amin, Shilu; Donaldson, Ian J.; Zannino, Denise A.; Hensman, James; Rattray, Magnus; Losa, Marta; Spitz, François; Ladam, Franck; Sagerström, Charles; Bobola, Nicoletta

2015-01-01

Summary Hox transcription factors (TFs) are essential for vertebrate development, but how these evolutionary conserved proteins function in vivo remains unclear. Because Hox proteins have notoriously low binding specificity, they are believed to bind with cofactors, mainly homeodomain TFs Pbx and Meis, to select their specific targets. We mapped binding of Meis, Pbx, and Hoxa2 in the branchial arches, a series of segments in the developing vertebrate head. Meis occupancy is largely similar in Hox-positive and -negative arches. Hoxa2, which specifies second arch (IIBA) identity, recognizes a subset of Meis prebound sites that contain Hox motifs. Importantly, at these sites Meis binding is strongly increased. This enhanced Meis binding coincides with active enhancers, which are linked to genes highly expressed in the IIBA and regulated by Hoxa2. These findings show that Hoxa2 operates as a tissue-specific cofactor, enhancing Meis binding to specific sites that provide the IIBA with its anatomical identity. PMID:25640223

Statistical eruption forecast for the Chilean Southern Volcanic Zone: typical probabilities of volcanic eruptions as baseline for possibly enhanced activity following the large 2010 Concepción earthquake

Directory of Open Access Journals (Sweden)

Y. Dzierma

2010-10-01

Full Text Available A probabilistic eruption forecast is provided for ten volcanoes of the Chilean Southern Volcanic Zone (SVZ. Since 70% of the Chilean population lives in this area, the estimation of future eruption likelihood is an important part of hazard assessment. After investigating the completeness and stationarity of the historical eruption time series, the exponential, Weibull, and log-logistic distribution functions are fit to the repose time distributions for the individual volcanoes and the models are evaluated. This procedure has been implemented in two different ways to methodologically compare details in the fitting process. With regard to the probability of at least one VEI ≥ 2 eruption in the next decade, Llaima, Villarrica and Nevados de Chillán are most likely to erupt, while Osorno shows the lowest eruption probability among the volcanoes analysed. In addition to giving a compilation of the statistical eruption forecasts along the historically most active volcanoes of the SVZ, this paper aims to give "typical" eruption probabilities, which may in the future permit to distinguish possibly enhanced activity in the aftermath of the large 2010 Concepción earthquake.

Designing and testing scene enhancement algorithms for patients with retina degenerative disorders

Directory of Open Access Journals (Sweden)

Downes Susan M

2010-06-01

Full Text Available Abstract Background Retina degenerative disorders represent the primary cause of blindness in UK and in the developed world. In particular, Age Related Macular Degeneration (AMD and Retina Pigmentosa (RP diseases are of interest to this study. We have therefore created new image processing algorithms for enhancing the visual scenes for them. Methods In this paper we present three novel image enhancement techniques aimed at enhancing the remaining visual information for patients suffering from retina dystrophies. Currently, the only effective way to test novel technology for visual enhancement is to undergo testing on large numbers of patients. To test our techniques, we have therefore built a retinal image processing model and compared the results to data from patient testing. In particular we focus on the ability of our image processing techniques to achieve improved face detection and enhanced edge perception. Results Results from our model are compared to actual data obtained from testing the performance of these algorithms on 27 patients with an average visual acuity of 0.63 and an average contrast sensitivity of 1.22. Results show that Tinted Reduced Outlined Nature (TRON and Edge Overlaying algorithms are most beneficial for dynamic scenes such as motion detection. Image Cartoonization was most beneficial for spatial feature detection such as face detection. Patient's stated that they would most like to see Cartoonized images for use in daily life. Conclusions Results obtained from our retinal model and from patients show that there is potential for these image processing techniques to improve visual function amongst the visually impaired community. In addition our methodology using face detection and efficiency of perceived edges in determining potential benefit derived from different image enhancement algorithms could also prove to be useful in quantitatively assessing algorithms in future studies.

The enhanced piezoelectricity in compositionally graded ferroelectric thin films under electric field: A role of flexoelectric effect

Science.gov (United States)

Qiu, Ye; Wu, Huaping; Wang, Jie; Lou, Jia; Zhang, Zheng; Liu, Aiping; Chai, Guozhong

2018-02-01

Compositionally graded ferroelectric thin films are found to produce large strain gradients, which can be used to tune the physical properties of materials through the flexoelectric effect, i.e., the coupling of polarization and the strain gradient. The influences of the flexoelectric effect on the polarization distribution and the piezoelectric properties in compositionally graded Ba1-xSrxTiO3 ferroelectric thin films are investigated by using an extended thermodynamic theory. The calculation results show that the presence of the flexoelectric effect tends to enhance and stabilize polarization components. The polarization rotation induced by the flexoelectric field has been predicted, which is accompanied by more uniform and orderly polarization components. A remarkable enhancement of piezoelectricity is obtained when the flexoelectric field is considered, suggesting that compositionally graded Ba1-xSrxTiO3 ferroelectric thin films with a large strain gradient are promising candidates for piezoelectric devices.

High-Latitude Topside Ionospheric Vertical Electron Density Profile Changes in Response to Large Magnetic Storms

Science.gov (United States)

Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

2016-01-01

Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst -100nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial andor temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

Interfacial Layer Engineering for Performance Enhancement in Polymer Solar Cells

Directory of Open Access Journals (Sweden)

Hao Zeng

2015-02-01

Full Text Available Improving power conversion efficiency and device performance stability is the most critical challenge in polymer solar cells for fulfilling their applications in industry at large scale. Various methodologies have been developed for realizing this goal, among them interfacial layer engineering has shown great success, which can optimize the electrical contacts between active layers and electrodes and lead to enhanced charge transport and collection. Interfacial layers also show profound impacts on light absorption and optical distribution of solar irradiation in the active layer and film morphology of the subsequently deposited active layer due to the accompanied surface energy change. Interfacial layer engineering enables the use of high work function metal electrodes without sacrificing device performance, which in combination with the favored kinetic barriers against water and oxygen penetration leads to polymer solar cells with enhanced performance stability. This review provides an overview of the recent progress of different types of interfacial layer materials, including polymers, small molecules, graphene oxides, fullerene derivatives, and metal oxides. Device performance enhancement of the resulting solar cells will be elucidated and the function and operation mechanism of the interfacial layers will be discussed.

Enhancement of pool boiling heat transfer coefficients using carbon nanotubes

International Nuclear Information System (INIS)

Park, Ki Jung; Jung, Dong Soo

2007-01-01

In this study, the effect of carbon nanotubes (CNTs) on nucleate boiling heat transfer is investigated. Three refrigerants of R22, R123, R134a, and water were used as working fluids and 1.0 vol.% of CNTs was added to the working fluids to examine the effect of CNTs. Experimental apparatus was composed of a stainless steel vessel and a plain horizontal tube heated by a cartridge heater. All data were obtained at the pool temperature of 7 .deg. C for all refrigerants and 100 .deg. C for water in the heat flux range of 10∼80 kW/m 2 . Test results showed that CNTs increase nucleate boiling heat transfer coefficients for all fluids. Especially, large enhancement was observed at low heat fluxes of less than 30 kW/m 2 . With increasing heat flux, however, the enhancement was suppressed due to vigorous bubble generation. Fouling on the heat transfer surface was not observed during the course of this study. Optimum quantity and type of CNTs and their dispersion should be examined for their commercial application to enhance nucleate boiling heat transfer in many applications

Group Clustering Mechanism for P2P Large Scale Data Sharing Collaboration

Institute of Scientific and Technical Information of China (English)

DENGQianni; LUXinda; CHENLi

2005-01-01

Research shows that P2P scientific collaboration network will exhibit small-world topology, as do a large number of social networks for which the same pattern has been documented. In this paper we propose a topology building protocol to benefit from the small world feature. We find that the idea of Freenet resembles the dynamic pattern of social interactions in scientific data sharing and the small world characteristic of Freenet is propitious to improve the file locating performance in scientificdata sharing. But the LRU (Least recently used) datas-tore cache replacement scheme of Freenet is not suitableto be used in scientific data sharing network. Based onthe group locality of scientific collaboration, we proposean enhanced group clustering cache replacement scheme.Simulation shows that this scheme improves the request hitratio dramatically while keeping the small average hops per successful request comparable to LRU.

The Costs of an Enhanced Employee Assistance Program (EAP) Intervention.

Science.gov (United States)

French, Michael T.; Dunlap, Laura J.; Zarkin, Gary A.; Karuntzos, Georgia T.

1998-01-01

This study estimates the economic costs of an enhanced Employee Assistance Program (EAP) intervention at a large midwestern EAP that serves 90 worksites. Results specify developmental and implementation costs and provide benchmark cost estimated for other EAPs that may be considering enhanced services. (SLD)

Au nanoparticle arrays with tunable particle gaps by template-assisted electroless deposition for high performance surface-enhanced Raman scattering

International Nuclear Information System (INIS)

Mu Cheng; Xu Dongsheng; Zhang Jianping

2010-01-01

Surface-enhanced Raman spectroscopy (SERS) with enormous enhancements has shown great potential in ultrasensitive detection technologies, but the fabrication of large-scale, controllable and reproducible substrates with high SERS activity is a major challenge. Here, we report the preparation of Au nanoparticle arrays for SERS-active substrates with tunable particle sizes and interparticle gaps, and the enhancement factor of the SERS signal obtained from 4-mercaptopyridine probe molecules was as high as 10 7 . The experimental data points show the increase of enhancement factor as a function of the ratio of diameter to interparticle gap, which can be explained by the averaged electromagnetic field enhancement model. Furthermore, we demonstrated that this type of substrate merits its high uniformity, high reproducibility and excellent long-term stability. As the fabrication protocol of such a SERS substrate is simple and inexpensive, this substrate may anticipate a wide range of applications in SERS-based sensors.

Who Benefits from Pension Enhancements?

Science.gov (United States)

Koedel, Cory; Ni, Shawn; Podgursky, Michael

2014-01-01

During the late 1990s public pension funds across the United States accrued large actuarial surpluses. The seemingly flush conditions of the pension funds led legislators in most states to substantially improve retirement benefits for public workers, including teachers. In this study we examine the benefit enhancements to the teacher pension…

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

International Nuclear Information System (INIS)

Hosoya, T.; Adachi, M.; Sugai, Y.; Yamaguchi, K.; Yamaguchi, K.; Kato, T.

2001-01-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

Energy Technology Data Exchange (ETDEWEB)

Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

2001-04-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Large low-energy M1 strength for ^{56,57}Fe within the nuclear shell model.

Science.gov (United States)

Brown, B Alex; Larsen, A C

2014-12-19

A strong enhancement at low γ-ray energies has recently been discovered in the γ-ray strength function of ^{56,57}Fe. In this work, we have for the first time obtained theoretical γ decay spectra for states up to ≈8  MeV in excitation for ^{56,57}Fe. We find large B(M1) values for low γ-ray energies that provide an explanation for the experimental observations. The role of mixed E2 transitions for the low-energy enhancement is addressed theoretically for the first time, and it is found that they contribute a rather small fraction. Our calculations clearly show that the high-ℓ(=f) diagonal terms are most important for the strong low-energy M1 transitions. As such types of 0ℏω transitions are expected for all nuclei, our results indicate that a low-energy M1 enhancement should be present throughout the nuclear chart. This could have far-reaching consequences for our understanding of the M1 strength function at high excitation energies, with profound implications for astrophysical reaction rates.

Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

International Nuclear Information System (INIS)

Sardanelli, Francesco; Di Leo, Giovanni; Aliprandi, Alberto; Flor, Nicola; Papini, Giacomo D.E.; Roccatagliata, Luca; Cotticelli, Biagio; Nano, Giovanni; Cornalba, Gianpaolo

2009-01-01

Objectives: This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA). Materials and methods: IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET. Results: With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%). Conclusion: Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.

Ultra-rare mutation in long-range enhancer predisposes to thyroid carcinoma with high penetrance.

Directory of Open Access Journals (Sweden)

Huiling He

Full Text Available Thyroid cancer shows high heritability but causative genes remain largely unknown. According to a common hypothesis the genetic predisposition to thyroid cancer is highly heterogeneous; being in part due to many different rare alleles. Here we used linkage analysis and targeted deep sequencing to detect a novel single-nucleotide mutation in chromosome 4q32 (4q32A>C in a large pedigree displaying non-medullary thyroid carcinoma (NMTC. This mutation is generally ultra-rare; it was not found in 38 NMTC families, in 2676 sporadic NMTC cases or 2470 controls. The mutation is located in a long-range enhancer element whose ability to bind the transcription factors POU2F and YY1 is significantly impaired, with decreased activity in the presence of the C- allele compared with the wild type A-allele. An enhancer RNA (eRNA is transcribed in thyroid tissue from this region and is greatly downregulated in NMTC tumors. We suggest that this is an example of an ultra-rare mutation predisposing to thyroid cancer with high penetrance.

Increasing stress on disaster-risk finance due to large floods

Science.gov (United States)

Jongman, Brenden; Hochrainer-Stigler, Stefan; Feyen, Luc; Aerts, Jeroen C. J. H.; Mechler, Reinhard; Botzen, W. J. Wouter; Bouwer, Laurens M.; Pflug, Georg; Rojas, Rodrigo; Ward, Philip J.

2014-04-01

Recent major flood disasters have shown that single extreme events can affect multiple countries simultaneously, which puts high pressure on trans-national risk reduction and risk transfer mechanisms. So far, little is known about such flood hazard interdependencies across regions and the corresponding joint risks at regional to continental scales. Reliable information on correlated loss probabilities is crucial for developing robust insurance schemes and public adaptation funds, and for enhancing our understanding of climate change impacts. Here we show that extreme discharges are strongly correlated across European river basins. We present probabilistic trends in continental flood risk, and demonstrate that observed extreme flood losses could more than double in frequency by 2050 under future climate change and socio-economic development. We suggest that risk management for these increasing losses is largely feasible, and we demonstrate that risk can be shared by expanding risk transfer financing, reduced by investing in flood protection, or absorbed by enhanced solidarity between countries. We conclude that these measures have vastly different efficiency, equity and acceptability implications, which need to be taken into account in broader consultation, for which our analysis provides a basis.

Psychopaths Show Enhanced Amygdala Activation during Fear Conditioning

OpenAIRE

Schultz, Douglas H.; Balderston, Nicholas L.; Baskin-Sommers, Arielle R.; Larson, Christine L.; Helmstetter, Fred J.

2016-01-01

Psychopathy is a personality disorder characterized by emotional deficits and a failure to inhibit impulsive behavior and is often subdivided into “primary” and “secondary” psychopathic subtypes. The maladaptive behavior related to primary psychopathy is thought to reflect constitutional “fearlessness,” while the problematic behavior related to secondary psychopathy is motivated by other factors. The fearlessness observed in psychopathy has often been interpreted as reflecting a fundamental d...

A novel perovskite oxide chemically designed to show multiferroic phase boundary with room-temperature magnetoelectricity

Science.gov (United States)

Fernández-Posada, Carmen M.; Castro, Alicia; Kiat, Jean-Michel; Porcher, Florence; Peña, Octavio; Algueró, Miguel; Amorín, Harvey

2016-09-01

There is a growing activity in the search of novel single-phase multiferroics that could finally provide distinctive magnetoelectric responses at room temperature, for they would enable a range of potentially disruptive technologies, making use of the ability of controlling polarization with a magnetic field or magnetism with an electric one (for example, voltage-tunable spintronic devices, uncooled magnetic sensors and the long-searched magnetoelectric memory). A very promising novel material concept could be to make use of phase-change phenomena at structural instabilities of a multiferroic state. Indeed, large phase-change magnetoelectric response has been anticipated by a first-principles investigation of the perovskite BiFeO3-BiCoO3 solid solution, specifically at its morphotropic phase boundary between multiferroic polymorphs of rhombohedral and tetragonal symmetries. Here, we report a novel perovskite oxide that belongs to the BiFeO3-BiMnO3-PbTiO3 ternary system, chemically designed to present such multiferroic phase boundary with enhanced ferroelectricity and canted ferromagnetism, which shows distinctive room-temperature magnetoelectric responses.

Enhanced photoelastic modulation in silica phononic crystal cavities

Science.gov (United States)

Kim, Ingi; Iwamoto, Satoshi; Arakawa, Yasuhiko

2018-04-01

The enhanced photoelastic modulation in quasi-one-dimensional (1D) phononic crystal (PnC) cavities made of fused silica is experimentally demonstrated. A confined acoustic wave in the cavity can induce a large birefringence through the photoelastic effect and enable larger optical modulation amplitude at the same acoustic power. We observe a phase retardation of ∼26 mrad of light passing through the cavity when the exciting acoustic frequency is tuned to the cavity mode resonance of ∼500 kHz at 2.5 V. In the present experiment, a 16-fold enhancement of retardation in the PnC cavity is demonstrated compared with that in a bar-shaped silica structure. Spatially resolved optical retardation measurement reveals that the large retardation is realized only around the cavity reflecting the localized nature of the acoustic cavity mode. The enhanced interactions between acoustic waves and light can be utilized to improve the performance of acousto-optic devices such as photoelastic modulators.

Relationship between Length and Surface-Enhanced Raman Spectroscopy Signal Strength in Metal Nanoparticle Chains: Ideal Models versus Nanofabrication

Directory of Open Access Journals (Sweden)

Kristen D. Alexander

2012-01-01

Full Text Available We have employed capillary force deposition on ion beam patterned substrates to fabricate chains of 60 nm gold nanospheres ranging in length from 1 to 9 nanoparticles. Measurements of the surface-averaged SERS enhancement factor strength for these chains were then compared to the numerical predictions. The SERS enhancement conformed to theoretical predictions in the case of only a few chains, with the vast majority of chains tested not matching such behavior. Although all of the nanoparticle chains appear identical under electron microscope observation, the extreme sensitivity of the SERS enhancement to nanoscale morphology renders current nanofabrication methods insufficient for consistent production of coupled nanoparticle chains. Notwithstanding this fact, the aggregate data also confirmed that nanoparticle dimers offer a large improvement over the monomer enhancement while conclusively showing that, within the limitations imposed by current state-of-the-art nanofabrication techniques, chains comprising more than two nanoparticles provide only a marginal signal boost over the already considerable dimer enhancement.

Contrast enhancement pattern in MR imaging of acute cerebral infarction

International Nuclear Information System (INIS)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon

1994-01-01

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days

Contrast enhancement pattern in MR imaging of acute cerebral infarction

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon [Inje University College of Medicine, Pusan (Korea, Republic of)

1994-08-15

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days.

Two Stroke Diesel Engines for Large Ship Propulsion

DEFF Research Database (Denmark)

Haider, Sajjad

In low speed large two-stroke marine diesel engines, uniflow scavenging is used to remove the exhaust gases from the cylinder and fill the cylinder with fresh air charge for the next cycle. The swirl enhances the mixing of fuel with air and improves combustion efficiency. The thesis focuses...... downstream. As the port closes, the mixing of smoke particles in the core with surrounding regions is enhanced. The hollow conical smoke pattern disappears and resembles to a jet. Laser Doppler Anemometry measurements are conducted in the swirl generator and at the entrance to the test cylinder. The results...

Mitigation and enhancement techniques for the Upper Mississippi River system and other large river systems

Science.gov (United States)

Schnick, Rosalie A.; Morton, John M.; Mochalski, Jeffrey C.; Beall, Jonathan T.

1982-01-01

Extensive information is provided on techniques that can reduce or eliminate the negative impact of man's activities (particularly those related to navigation) on large river systems, with special reference to the Upper Mississippi River. These techniques should help resource managers who are concerned with such river systems to establish sound environmental programs. Discussion of each technique or group of techniques include (1) situation to be mitigated or enhanced; (2) description of technique; (3) impacts on the environment; (4) costs; and (5) evaluation for use on the Upper Mississippi River Systems. The techniques are divided into four primary categories: Bank Stabilization Techniques, Dredging and Disposal of Dredged Material, Fishery Management Techniques, and Wildlife Management Techniques. Because techniques have been grouped by function, rather than by structure, some structures are discussed in several contexts. For example, gabions are discussed for use in revetments, river training structures, and breakwaters. The measures covered under Bank Stabilization Techniques include the use of riprap revetments, other revetments, bulkheads, river training structures, breakwater structures, chemical soil stabilizers, erosion-control mattings, and filter fabrics; the planting of vegetation; the creation of islands; the creation of berms or enrichment of beaches; and the control of water level and boat traffic. The discussions of Dredging and the Disposal of Dredged Material consider dredges, dredging methods, and disposal of dredged material. The following subjects are considered under Fishery Management Techniques: fish attractors; spawning structures; nursery ponds, coves, and marshes; fish screens and barriers; fish passage; water control structures; management of water levels and flows; wing dam modification; side channel modification; aeration techniques; control of nuisance aquatic plants; and manipulated of fish populations. Wildlife Management

Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

International Nuclear Information System (INIS)

Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

2003-01-01

To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

Enhancing Rotational Diffusion Using Oscillatory Shear

KAUST Repository

Leahy, Brian D.; Cheng, Xiang; Ong, Desmond C.; Liddell-Watson, Chekesha; Cohen, Itai

2013-01-01

Taylor dispersion - shear-induced enhancement of translational diffusion - is an important phenomenon with applications ranging from pharmacology to geology. Through experiments and simulations, we show that rotational diffusion is also enhanced

IM-Chem: The Use of Instant Messaging to Improve Student Performance and Personalize Large Lecture General Chemistry Courses

Science.gov (United States)

Behmke, Derek A.; Atwood, Charles H.

2012-01-01

Previous research has linked poor student performance with the depersonalized feeling of large lecture courses. Various forms of enhanced communication have been tried that appear to enhance personalization in large courses. For general chemistry classes taught in a 365-seat lecture hall at the University of Georgia, we have attempted to enhance…

Primary central nervous system diffuse large B-cell lymphoma shows an activated B-cell-like phenotype with co-expression of C-MYC, BCL-2, and BCL-6.

Science.gov (United States)

Li, Xiaomei; Huang, Ying; Bi, Chengfeng; Yuan, Ji; He, Hong; Zhang, Hong; Yu, QiuBo; Fu, Kai; Li, Dan

2017-06-01

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, whose main prognostic factor is closely related to germinal center B-cell-like subtype (GCB- DLBCL) or activated B-cell-like type (non-GCB-DLBCL). The most common type of primary central nervous system lymphoma is diffuse large B-cell type with poor prognosis and the reason is unclear. This study aims to stratify primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) according to the cell-of-origin (COO) and to investigate the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53, further to elucidate the reason why primary central nervous system diffuse large B-cell lymphoma possesses a poor clinical outcome as well. Nineteen cases of primary central nervous system DLBCL were stratified according to immunostaining algorithms of Hans, Choi and Meyer (Tally) and we investigated the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53. The Epstein-Barr virus and Borna disease virus infection were also detected. Among nineteen cases, most (15-17 cases) were assigned to the activated B-cell-like subtype, highly expression of C-MYC (15 cases, 78.9%), BCL-2 (10 cases, 52.6%), BCL-6 (15 cases, 78.9%). Unfortunately, two cases were positive for PD-L1 while PD-L2 was not expressed in any case. Two cases infected with BDV but no one infected with EBV. In conclusion, most primary central nervous system DLBCLs show an activated B-cell-like subtype characteristic and have multiple expressions of C-MYC, BCL-2, BCL-6 protein, these features might be significant factor to predict the outcome and guide treatment of PCNS-DLBCLs. Copyright © 2017 Elsevier GmbH. All rights reserved.

Recovering from trust breakdowns in large system implementations

DEFF Research Database (Denmark)

Rerup Schlichter, Bjarne Rerup; Andersen, Povl Erik Rostgård

2011-01-01

On the basis of experiences from the Faroese large-scale implementation of integrated healthcare information systems and insights into dynamic aspects of trust, we offer the following lessons learned for the successful management and recovery of trust (breakdowns) in large system implementations......: restore relations by turning towards face-to-face events and procedures, assure a well-functioning and available support organization, demonstrate trust in actors to enhance their own self-confidence and celebrate successes, even the smallest or ones injected by yourself. The propositions are based on a 6...

Effect of large compressive strain on low field electrical transport in La0.88Sr0.12MnO3 thin films

International Nuclear Information System (INIS)

Prasad, Ravikant; Gaur, Anurag; Siwach, P K; Varma, G D; Kaur, A; Singh, H K

2007-01-01

We have investigated the effect of large in-plane compressive strain on the electrical transport in La 0.88 Sr 0.12 MnO 3 in thin films. For achieving large compressive strain, films have been deposited on single crystal LaAlO 3 (LAO, a = 3.798 A) substrate from a polycrystalline bulk target having average in-plane lattice parameter a av = (a b + b b )/2 = 3.925 A. The compressive strain was further relaxed by varying the film thickness in the range ∼6-75 nm. In the film having least thickness (∼6 nm) large increase (c = 3.929 A) in the out-of-plane lattice parameter is observed which gradually decreases towards the bulk value (c bulk = 3.87 A) for ∼75 nm thick film. This shows that the film having the least thickness is under large compressive strain, which partially relaxes with increasing film thickness. The T IM of the bulk target ∼145 K goes up to ∼235 K for the ∼6 nm thin film and even for partially strain relaxed ∼75 nm thick film T IM is as high as ∼200 K. This enhancement in T IM is explained in terms of suppression of Jahn-Teller distortion of the MnO 6 octahedra by the large in-plane compressive strain. We observe a large enhancement in the low field magnetoresistance (MR) just below T IM in the films having partial strain relaxation. Thick films of 6 and 20 nm have MR ∼14% at 3 kOe that almost doubles in 35 nm film to ∼27%. Similar enhancement is also obtained in the case of the temperature coefficient of resistivity. The near doubling of low field MR is explained in terms of delocalization of weakly localized carriers around T IM by small magnetic fields

Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Takano, Koichi, E-mail: k-takano@fukuoka-u.ac.jp; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

2017-01-15

Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

International Nuclear Information System (INIS)

Takano, Koichi; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

2017-01-01

Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

Large-scale grid management

International Nuclear Information System (INIS)

Langdal, Bjoern Inge; Eggen, Arnt Ove

2003-01-01

The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series

Provision of enhanced ancillary services from wind power plants - Examples and challenges

DEFF Research Database (Denmark)

Hansen, Anca Daniela; Altin, Müfit; Iov, Florin

2016-01-01

Emphasis in this article is on the power system impact of wind power plants capability to provide enhanced ancillary services, i.e. temporary frequency response (TFR) and power oscillation damping (POD). The main objective of the article is to analyze and justify the challenges in the use of TFR...... and POD from wind power plants (WPPs). The study is conducted with an aggregated wind power plant model which is integrated into a generic power system model, specifically designed to assess the targeted ancillary services in a relatively simple, but still relevant environment. Various case studies...... with different wind power penetration levels are considered. The study shows that WPPs can provide additional control features such as TFR and POD to enhance the stability of power systems with large share of wind power. Nevertheless, the results illustrate that the power system stability can be potentially...

Remote Sensing Image Enhancement Based on Non-subsampled Shearlet Transform and Parameterized Logarithmic Image Processing Model

Directory of Open Access Journals (Sweden)

TAO Feixiang

2015-08-01

Full Text Available Aiming at parts of remote sensing images with dark brightness and low contrast, a remote sensing image enhancement method based on non-subsampled Shearlet transform and parameterized logarithmic image processing model is proposed in this paper to improve the visual effects and interpretability of remote sensing images. Firstly, a remote sensing image is decomposed into a low-frequency component and high frequency components by non-subsampled Shearlet transform.Then the low frequency component is enhanced according to PLIP (parameterized logarithmic image processing model, which can improve the contrast of image, while the improved fuzzy enhancement method is used to enhance the high frequency components in order to highlight the information of edges and details. A large number of experimental results show that, compared with five kinds of image enhancement methods such as bidirectional histogram equalization method, the method based on stationary wavelet transform and the method based on non-subsampled contourlet transform, the proposed method has advantages in both subjective visual effects and objective quantitative evaluation indexes such as contrast and definition, which can more effectively improve the contrast of remote sensing image and enhance edges and texture details with better visual effects.

Using Market Segmentation to Develop a Large Section, Web-Enhanced Survey Course

Science.gov (United States)

Cole, Jason; Robertson, Bruce

2006-01-01

Increasing enrollment and decreasing budgets have caused many public universities, such as San Fransisco State University (SFU), to offer mega-sections of courses to hundreds of students. Yet the needs of many students are at odds with the large enrollments, inflexible times, and inconvenient locations of these classes. Jason Cole and Bruce…

BIR 2014 - Bibliometric-enhanced Information Retrieval

DEFF Research Database (Denmark)

This first “Bibliometric-enhanced Information Retrieval” (BIR 2014) workshop1 aims to engage with the IR community about possible links to bibliometrics and scholarly communication. Bibliometric techniques are not yet widely used to enhance retrieval processes in digital libraries, although...... analysis of co-authorship network, can improve retrieval services for specific communities, as well as for large, cross-domain collections. This workshop aims to raise awareness of the missing link between information retrieval (IR) and bibliometrics / scientometrics and to create a common ground...... for the incorporation of bibliometric-enhanced services into retrieval at the digital library interface. Our interests include information retrieval, information seeking, science modelling, network analysis, and digital libraries. The goal is to apply insights from bibliometrics, scientometrics, and informetrics...

Image enhancement of optical images for binary system of melanocytes and keratinocytes

Science.gov (United States)

Takanezawa, S.; Baba, A.; Sako, Y.; Ozaki, Y.; Date, A.; Toyama, K.; Morita, S.

2013-05-01

Automatic determination of the cell shapes of large numbers of melanocytes based on optical images of human skin models have been largely unsuccessful (the complexities introduced by dendrites and the melanin pigmentation over the keratinocytes to give unclear outlines). Here, we present an image enhancement procedure for enhancing the contrast of images with removing the non-uniformity of background. The brightness is normalized also for the non-uniform population density of melanocytes.

Enhancement of broadband optical absorption in photovoltaic devices by band-edge effect of photonic crystals.

Science.gov (United States)

Tanaka, Yoshinori; Kawamoto, Yosuke; Fujita, Masayuki; Noda, Susumu

2013-08-26

We numerically investigate broadband optical absorption enhancement in thin, 400-nm thick microcrystalline silicon (µc-Si) photovoltaic devices by photonic crystals (PCs). We realize absorption enhancement by coupling the light from the free space to the large area resonant modes at the photonic band-edge induced by the photonic crystals. We show that multiple photonic band-edge modes can be produced by higher order modes in the vertical direction of the Si photovoltaic layer, which can enhance the absorption on multiple wavelengths. Moreover, we reveal that the photonic superlattice structure can produce more photonic band-edge modes that lead to further optical absorption. The absorption average in wavelengths of 500-1000 nm weighted to the solar spectrum (AM 1.5) increases almost twice: from 33% without photonic crystal to 58% with a 4 × 4 period superlattice photonic crystal; our result outperforms the Lambertian textured structure.

Giant Magnetic Field Enhancement in Hybridized MIM Structures

KAUST Repository

Alrasheed, Salma

2017-10-23

We propose numerically an approach to narrow the plasmon linewidth and enhance the magnetic near field intensity at a magnetic hot spot in a hybridized metal-insulatormetal (MIM) structure. First we insert in part of the dielectric layer of the MIM, at its center, another dielectric material of a high refractive index (HRI). This results in an increase in the magnetic near field enhancement of the magnetic plasmon (MP) resonance by 82% compared with the MIM without the HRI material. We then couple this enhanced MP resonance to a propagating surface plasmon polariton (SPP) to achieve a further enhancement of 438%. The strong coupling between the MP and the SPP is demonstrated by the large anti-crossing in the reflection spectra. The resulting maximum magnetic field enhancement at the gap is ~ |H / Hi|² = 3555.

Underwater video enhancement using multi-camera super-resolution

Science.gov (United States)

Quevedo, E.; Delory, E.; Callicó, G. M.; Tobajas, F.; Sarmiento, R.

2017-12-01

Image spatial resolution is critical in several fields such as medicine, communications or satellite, and underwater applications. While a large variety of techniques for image restoration and enhancement has been proposed in the literature, this paper focuses on a novel Super-Resolution fusion algorithm based on a Multi-Camera environment that permits to enhance the quality of underwater video sequences without significantly increasing computation. In order to compare the quality enhancement, two objective quality metrics have been used: PSNR (Peak Signal-to-Noise Ratio) and the SSIM (Structural SIMilarity) index. Results have shown that the proposed method enhances the objective quality of several underwater sequences, avoiding the appearance of undesirable artifacts, with respect to basic fusion Super-Resolution algorithms.

Why pellet fuelling of large machines?

International Nuclear Information System (INIS)

Anon.

1986-01-01

Arguments for pellet fueling as a way to optimize the density profile in large machines with respect to the density limit, the beta limit, energy confinement and requirements for hydrogen and helium pumping are reviewed. It is concluded that pellets can be used as a way to overcome the density limit and enhance energy confinement but there is currently no clear argument for density profile shaping. Pumping requirements are lowered for deep fueling

GMP-grade platelet lysate enhances proliferation and migration of tenon fibroblasts.

Science.gov (United States)

Carducci, Augusto; Scafetta, Gaia; Siciliano, Camilla; Carnevale, Roberto; Rosa, Paolo; Coccia, Andrea; Mangino, Giorgio; Bordin, Antonella; Vingolo, Enzo Maria; Pierelli, Luca; Lendaro, Eugenio; Ragona, Giuseppe; Frati, Giacomo; De Falco, Elena

2016-01-01

Tenon's fibroblasts (TFs), widely employed as in vitro model for many ophthalmological studies, are routinely cultured with FBS. Platelet Lysate (PL), a hemoderivate enriched with growth factors and cytokines has been largely tested in several clinical applications and as substitute of FBS in culture. Here, we investigate whether PL can exert biological effects on TF populations similarly to other cell types. Results show that PL significantly enhances cell proliferation and migration vs. FBS, without influencing cell size/granularity. Upregulation of EGF, VEGF, KDR, MMP2-9, FAK mRNA levels also occurs and phosphorylation of AKT but not of ERK1/2 is significantly enhanced. The inhibition of the PI3kinase/AKT pathway with the specific inhibitor wortmannin, decreases PL-induced cell migration but not proliferation. Condition supernatants containing PL show increased bioavailability of Nitric Oxide and reduced levels of 8-Iso-PGF2-alpha, correlating with cell proliferation and migration. Pro-angiogenic/inflammatory soluble factors (GRO, Angiogenin, EGF, I-309, PARC) are exclusively or greater expressed in media containing PL than FBS. GMP-grade PL preparations positively influence in vitro biological effects of TFs representing a suitable and safer alternative to FBS.

Superhydrophobicity enhancement through substrate flexibility

Science.gov (United States)

Vasileiou, Thomas; Gerber, Julia; Prautzsch, Jana; Schutzius, Thomas; Poulikakos, Dimos

2017-11-01

Inspired by manifestations in nature, micro/nanoengineering superhydrophobic surfaces has been the focus of much work. Generally, hydrophobicity is increased through the combined effects of surface texturing and chemistry; being durable, rigid substrate materials are the norm. However, many natural and technical materials are flexible, and the resulting effect on hydrophobicity has been largely unexplored. Here, we show that the rational tuning of flexibility can work collaboratively with the surface micro/nanotexture to enhance liquid repellency performance, defined by impalement and breakup resistance, contact time reduction, and restitution coefficient increase. Reduction in substrate stiffness and areal density imparts immediate acceleration and intrinsic responsiveness to impacting droplets, mitigating the collision and lowering the impalement probability by 60 % without the need for active actuation. We demonstrate the above discoveries with materials ranging from thin steel or polymer sheets to butterfly wings. Partial support of the Swiss National Science Foundation under Grant 162565 and the European Research Council under Advanced Grant 669908 (INTICE) is acknowledged.

ChIP-seq Identification of Weakly Conserved Heart Enhancers

Energy Technology Data Exchange (ETDEWEB)

Blow, Matthew J.; McCulley, David J.; Li, Zirong; Zhang, Tao; Akiyama, Jennifer A.; Holt, Amy; Plajzer-Frick, Ingrid; Shoukry, Malak; Wright, Crystal; Chen, Feng; Afzal, Veena; Bristow, James; Ren, Bing; Black, Brian L.; Rubin, Edward M.; Visel, Axel; Pennacchio, Len A.

2010-07-01

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of heart enhancers. Here we used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over three thousand candidate heart enhancers genome-wide. Compared to other tissues studied at this time-point, most candidate heart enhancers are less deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary constraint of embryonic enhancers can vary depending on tissue type.

Universal transport characteristics of multiple topological superconducting wires with large charging energy

Energy Technology Data Exchange (ETDEWEB)

Kashuba, Oleksiy; Trauzettel, Bjoern [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg, 97074 Wuerzburg (Germany); Timm, Carsten [Institut fuer Theoretische Physik, TU Dresden, 01062 Dresden (Germany)

2016-07-01

The system with multiple Majorana states coupled to the normal lead can potentially support the interaction between Majorana fermions and electrons. Such system can be implemented by several floating topological superconducting wires with large charging energy asymmetrically coupled to two normal leads. The analysis of the renormalization flow shows that there is a single fixed point - the strong coupling limit of isotropic antiferromagnetic Kondo model. The topological Kondo-like interaction leads also to the selective renormalization of the tunneling coefficients, strongly enhancing one component and suppressing others. Thus, charging energy crucially changes the transport properties of the system leading to the universal single-channel conductance independently from the values of the initial leads-wires coupling.

Metal-enhanced galactic winds. I

International Nuclear Information System (INIS)

Vader, J.P.

1986-01-01

Supernova-driven gas loss during the early evolution of elliptical galaxies is considered as a possible explanation for the correlations among the observed chemical and structural properties of these systems. Mass loss from systems with a chemically homogeneous interstellar medium does not work. It is pointed out that supernova-driven winds are in fact metal-enhanced with respect to the star-forming gas because the metal production of any supernova that drives the wind is directly flushed out of the galaxy. The fraction of the total metal production lost in the wind is thus at least as large as the fraction epsilon(z) of supernovae that power the wind, independent of the total mass loss. As a corollary, the yield of heavy elements that are recycled in the galaxy is reduced by a factor 1 - epsilon(z). Metal-enhanced galactic winds, which can carry away a large fraction of the metal production in spite of a moderate total mass loss, offer a promising explanation for the low metallicities of dwarf elliptical galaxies. 62 references

Heat transfer enhancement on nucleate boiling

International Nuclear Information System (INIS)

Zhuang, M.; Guibai, L.

1990-01-01

This paper reports on enhancement of nucleate boiling heat transfer with additives that was investigated experimentally. More than fifteen kinds of additives were chosen and tested. Eight kinds of effective additives which can enhance nucleate boiling heat transfer were selected. Experimental results showed that boiling heat transfer coefficient of water was increased by 1 to 5 times and that of R-113 was increased by 1 to 4 times when trace amount additives were put in the two boiling liquids. There exist optimum concentrations for the additives, respectively, which can enhance nucleate boiling heat transfer rate best. In order to analyze the mechanism of the enhancement of boiling heat transfer with additives, the surface tension and the bubble departure diameter were measured. The nucleation sites were investigated by use of high-speed photograph. Experimental results showed that nucleation sites increase with additive amount increasing and get maximum. Increasing nucleation sites is one of the most important reason why nucleate boiling heat transfer can be enhanced with additives

Data Integration for Microarrays: Enhanced Inference for Gene Regulatory Networks

Directory of Open Access Journals (Sweden)

Alina Sîrbu

2015-05-01

Full Text Available Microarray technologies have been the basis of numerous important findings regarding gene expression in the few last decades. Studies have generated large amounts of data describing various processes, which, due to the existence of public databases, are widely available for further analysis. Given their lower cost and higher maturity compared to newer sequencing technologies, these data continue to be produced, even though data quality has been the subject of some debate. However, given the large volume of data generated, integration can help overcome some issues related, e.g., to noise or reduced time resolution, while providing additional insight on features not directly addressed by sequencing methods. Here, we present an integration test case based on public Drosophila melanogaster datasets (gene expression, binding site affinities, known interactions. Using an evolutionary computation framework, we show how integration can enhance the ability to recover transcriptional gene regulatory networks from these data, as well as indicating which data types are more important for quantitative and qualitative network inference. Our results show a clear improvement in performance when multiple datasets are integrated, indicating that microarray data will remain a valuable and viable resource for some time to come.

Data Integration for Microarrays: Enhanced Inference for Gene Regulatory Networks.

Science.gov (United States)

Sîrbu, Alina; Crane, Martin; Ruskin, Heather J

2015-05-14

Microarray technologies have been the basis of numerous important findings regarding gene expression in the few last decades. Studies have generated large amounts of data describing various processes, which, due to the existence of public databases, are widely available for further analysis. Given their lower cost and higher maturity compared to newer sequencing technologies, these data continue to be produced, even though data quality has been the subject of some debate. However, given the large volume of data generated, integration can help overcome some issues related, e.g., to noise or reduced time resolution, while providing additional insight on features not directly addressed by sequencing methods. Here, we present an integration test case based on public Drosophila melanogaster datasets (gene expression, binding site affinities, known interactions). Using an evolutionary computation framework, we show how integration can enhance the ability to recover transcriptional gene regulatory networks from these data, as well as indicating which data types are more important for quantitative and qualitative network inference. Our results show a clear improvement in performance when multiple datasets are integrated, indicating that microarray data will remain a valuable and viable resource for some time to come.

Cholinergic enhancement of visual attention and neural oscillations in the human brain.

Science.gov (United States)

Bauer, Markus; Kluge, Christian; Bach, Dominik; Bradbury, David; Heinze, Hans Jochen; Dolan, Raymond J; Driver, Jon

2012-03-06

Cognitive processes such as visual perception and selective attention induce specific patterns of brain oscillations. The neurochemical bases of these spectral changes in neural activity are largely unknown, but neuromodulators are thought to regulate processing. The cholinergic system is linked to attentional function in vivo, whereas separate in vitro studies show that cholinergic agonists induce high-frequency oscillations in slice preparations. This has led to theoretical proposals that cholinergic enhancement of visual attention might operate via gamma oscillations in visual cortex, although low-frequency alpha/beta modulation may also play a key role. Here we used MEG to record cortical oscillations in the context of administration of a cholinergic agonist (physostigmine) during a spatial visual attention task in humans. This cholinergic agonist enhanced spatial attention effects on low-frequency alpha/beta oscillations in visual cortex, an effect correlating with a drug-induced speeding of performance. By contrast, the cholinergic agonist did not alter high-frequency gamma oscillations in visual cortex. Thus, our findings show that cholinergic neuromodulation enhances attentional selection via an impact on oscillatory synchrony in visual cortex, for low rather than high frequencies. We discuss this dissociation between high- and low-frequency oscillations in relation to proposals that lower-frequency oscillations are generated by feedback pathways within visual cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

LASSIE: the large analogue signal and scaling information environment for FAIR

International Nuclear Information System (INIS)

Hoffmann, T.; Braeuning, H.; Haseitl, R.

2012-01-01

At FAIR, the Facility for Antiproton and Ion Research, several new accelerators and storage rings such as the SIS-100, HESR, CR, the inter-connecting HEBT beam lines, S-FRS and experiments will be built. All of these installations are equipped with beam diagnostic devices and other components, which deliver time-resolved analogue signals to show status, quality and performance of the accelerators. These signals can originate from particle detectors such as ionization chambers and plastic scintillators, but also from adapted output signals of transformers, collimators, magnet functions, RF cavities and others. To visualize and precisely correlate the time axis of all input signals a dedicated FESA based data acquisition and analysis system named LASSIE, the Large Analogue Signal and Scaling Information Environment, is currently being developed. The main operation mode of LASSIE is currently pulse counting with latching VME scaler boards. Later enhancements for ADC, QDC, or TDC digitization in the future are foreseen. The concept, features and challenges of this large distributed data acquisition system are presented. (authors)

A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account

International Nuclear Information System (INIS)

Liu, Jizhen; Meng, Hongmin; Hu, Yang; Lin, Zhongwei; Wang, Wei

2015-01-01

Highlights: • We discuss the disadvantages of conventional OTC MPPT method. • We study the relationship between enhancing efficiency and power smoothing. • The conversion efficiency is enhanced and the volatility of power is suppressed. • Small signal analysis is used to verify the effectiveness of proposed method. - Abstract: With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS

Sustainability of small reservoirs and large scale water availability under current conditions and climate change

NARCIS (Netherlands)

Krol, Martinus S.; de Vries, Marjella J.; van Oel, Pieter R.; Carlos de Araújo, José

2011-01-01

Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

International Nuclear Information System (INIS)

Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

2013-01-01

Highlights: ► Ferromagnetic materials guide the flux distribution of the PMG to bulk positions. ► With ferromagnetic materials, guidance performance can be enhanced greatly. ► A new HTS Maglev system with onboard ferromagnetic materials is designed. ► The design can meet large guidance force requirements for practical applications. -- Abstract: Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves

EDITORIAL: Nano-enhanced! Nano-enhanced!

Science.gov (United States)

Demming, Anna

2010-08-01

In the early 19th century, a series of engineering and scientific breakthroughs by Nicolas Léonard Sadi Carnot, James Watt and many others led to the foundations of thermodynamics and a new pedigree of mechanical designs that reset the standards of engineering efficiency. The result was the industrial revolution. In optical- and electronics- based nanotechnology research, a similarly subtle bargain is being made; we cannot alter the fact that systems have a finite response to external excitations, but what we can do is enhance that response. The promising attributes of ZnO have long been recognised; its large band gap and high exciton binding energy lend it to a number of applications from laser diodes, LEDs, optical waveguides and switches, and acousto-optic applications to sun cream. When this material is grown into nanowires and nanorods, the material gains a whole new dimension, as quantum confinement effects come into play. Discovery of the enhanced radiative recombination, which has potential for exploitation in many optical and opto-electronic applications, drove intensive research into investigating these structures and into finding methods to synthesise them with optimised properties. This research revealed further subtleties in the properties of these materials. One example is the work by researchers in the US reporting synthesis procedures that produced a yield—defined as the weight ratio of ZnO nanowires to the original graphite flakes—of 200%, and which also demonstrated, through photoluminescence analysis of nanowires grown on graphite flakes and substrates, that graphite induces oxygen vacancies during annealing, which enhances the deep-level to near-band-edge emission ratio [1]. Other one-dimensional materials that provide field emission enhancements include carbon nanotubes, and work has been performed to find ways of optimising the emission efficiency from these structures, such as through control of the emitter density [2]. One of the

STORIES OF TECHNOLOGY-ENHANCEMENT IN HIGHER EDUCATION – A CRITICAL APPROACH

Directory of Open Access Journals (Sweden)

Trine Fossland

2016-11-01

Full Text Available There is a large body of research on technology-enhanced learning, but questions related to the educational effectiveness of technology use still needs to be questioned. In this paper, I argue that digital innovators’ stories about technology enhancement may constitute a rich source for understanding this complex educational phenomenon both in relation to teachers’ daily practices and the implementation of ICT in higher education at large. Based on biographical interviews with “digital innovators”, the aim of this paper is to investigate how [their] digital competence is used to enhance teaching and learning in higher education. This paper asks; how do digital innovators approach the use of ICT to enhance students’ learning and what are the organisational conditions for this approach? The findings suggests that technology-enhancement is linked to nine key characteristics: different educational models, authenticity, pedagogical added values, meaningful student activities, changing approaches to feedback, assessment and connection with the outside world, as well as holistic planning, supportive leaders and strong micro-cultures. This paper proposes a more nuanced understanding of the term technology enhanced learning and suggests strategies for educational development and further investigations related to this phenomenon in higher education.

Quantitative analysis of enhanced malignant and benign lesions on contrast-enhanced spectral mammography.

Science.gov (United States)

Deng, Chih-Ying; Juan, Yu-Hsiang; Cheung, Yun-Chung; Lin, Yu-Ching; Lo, Yung-Feng; Lin, GiGin; Chen, Shin-Cheh; Ng, Shu-Hang

2018-02-27

To retrospectively analyze the quantitative measurement and kinetic enhancement among pathologically proven benign and malignant lesions using contrast-enhanced spectral mammography (CESM). We investigated the differences in enhancement between 44 benign and 108 malignant breast lesions in CESM, quantifying the extent of enhancements and the relative enhancements between early (between 2-3 min after contrast medium injection) and late (3-6 min) phases. The enhancement was statistically stronger in malignancies compared to benign lesions, with good performance by the receiver operating characteristic curve [0.877, 95% confidence interval (0.813-0.941)]. Using optimal cut-off value at 220.94 according to Youden index, the sensitivity was 75.9%, specificity 88.6%, positive likelihood ratio 6.681, negative likelihood ratio 0.272 and accuracy 82.3%. The relative enhancement patterns of benign and malignant lesions, showing 29.92 vs 73.08% in the elevated pattern, 7.14 vs 92.86% in the steady pattern, 5.71 vs 94.29% in the depressed pattern, and 80.00 vs 20.00% in non-enhanced lesions (p < 0.0001), respectively. Despite variations in the degree of tumour angiogenesis, quantitative analysis of the breast lesions on CESM documented the malignancies had distinctive stronger enhancement and depressed relative enhancement patterns than benign lesions. Advances in knowledge: To our knowledge, this is the first study evaluating the feasibility of quantifying lesion enhancement on CESM. The quantities of enhancement were informative for assessing breast lesions in which the malignancies had stronger enhancement and more relative depressed enhancement than the benign lesions.

Oxide interfaces with enhanced ion conductivity

NARCIS (Netherlands)

Leon, C.; Santamaria, J.; Boukamp, Bernard A.

2013-01-01

The new field of nano-ionics is expected to yield large improvements in the performance of oxide-based energy generation and storage devices based on exploiting size effects in ion conducting materials. The search for novel materials with enhanced ionic conductivity for application in energy devices

Enhanced J/psi suppression due to gluon depletion

OpenAIRE

Hwa, R. C.; Pisut, J.; Pisutova, N.

1997-01-01

The nonlinear effect of gluon depletion in the collision of large nuclei can be large. It is due to multiple scatterings among comoving partons initiated by primary scattering of partons in the colliding nuclei. The effect can give rise to substantial suppression of $J/\\psi$ production in very large nuclei, even if the linear depletion effect is insignificant for the collisions of nuclei of smaller sizes. This mechanism offers a natural explanation of the enhanced suppression in the Pb-Pb dat...

Statistical Characteristics of Solar Wind Dynamic Pressure Enhancements During Geomagnetic Storms

Directory of Open Access Journals (Sweden)

C.-R. Choi

2008-06-01

Full Text Available Solar wind dynamic pressure enhancements are known to cause various types of disturbances to the magnetosphere. In particular, dynamic pressure enhancements may affect the evolution of magnetic storms when they occur during storm times. In this paper, we have investigated the statistical significance and features of dynamic pressure enhancements during magnetic storm times. For the investigation, we have used a total of 91 geomagnetic storms for 2001-2003, for which the Dst minimum (Dst_min is below -50 nT. Also, we have imposed a set of selection criteria for a pressure enhancement to be considered an event: The main selection criterion is that the pressure increases by ≥50% or ≥3nPa within 30 min and remains to be elevated for 10 min or longer. For our statistical analysis, we define the storm time to be the interval from the main Dst decrease, through Dst_min, to the point where the Dst index recovers by 50%. Our main results are summarized as follows. (i ~81% of the studied storms indicate at least one event of pressure enhancements. When averaged over all the 91 storms, the occurrence rate is 4.5 pressure enhancement events per storm and 0.15 pressure enhancement events per hour. (ii The occurrence rate of the pressure enhancements is about three times higher for CME-driven storm times than for CIR-driven storm times. (iii Only 21.1% of the pressure enhancements show a clear association with an interplanetary shock. (iv A large number of the pressure enhancement events are accompanied with a simultaneous change of IMF By and/or Bz: For example, 73.5% of the pressure enhancement events are associated with an IMF change of either |∆Bz|>2nT or |∆By|>2nT. This last finding suggests that one should consider possible interplay effects between the simultaneous pressure and IMF changes in many situations.

Detection of skeletal muscle metastasis: torso FDG PET-CT versus contrast-enhanced chest or abdomen CT.

Science.gov (United States)

So, Young; Yi, Jeong Geun; Song, Inyoung; Lee, Won Woo; Chung, Hyun Woo; Park, Jeong Hee; Moon, Sung Gyu

2015-07-01

Skeletal muscle metastasis (SMM) in cancer patients has not been sufficiently evaluated regarding prevalence and proper method of detection. To determine the prevalence of SMM and compare the diagnostic competencies for SMM of torso F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) and contrast-enhanced chest or abdomen CT. We investigated 18,225 PET-CT studies of 6359 cancer patients performed from 2005 to 2012. The PET-CT studies describing potential SMM were retrieved and the corresponding medical records were reviewed. The gold standard for SMM was histopathologically-proven SMM or imaging study-based disease progression. The detectability of SMM was compared between PET-CT and contrast-enhanced CT. Twenty-six patients had 84 SMM lesions, representing a SMM prevalence of 0.41%. Lung cancer was the most common SMM-associated malignancy (54%) and the gluteal/pelvic girdle muscle was the most frequently involved SMM site (37%). All 84 SMM lesions were visualized on PET-CT (100%). Of these PET-CT positive 84 SMM lesions, 51 lesions were in the CT field of view (FOV) (61%), whereas 33 lesions were out of the CT FOV (39%). Among these 51 lesions, 17 lesions showed rim-enhancing nodules/masses (33%), eight lesions showed homogeneously enhancing nodules (16%), three lesions showed heterogeneously enhancing nodules (6%), and 23 SMM lesions (45%) were non-diagnostic by CT. All 51 SMM lesions within CT FOV were detected on PET-CT (100%), whereas only 28 were visualized on CT (54.9%), resulting in a significant difference (P SMM was revealed by PET-CT. The prevalence of SMM was as low as 0.41% in the current large cohort of cancer patients. Torso PET-CT was a more competent modality than contrast-enhanced CT in the detection of SMM. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Large-Scale Analysis of Art Proportions

DEFF Research Database (Denmark)

Jensen, Karl Kristoffer

2014-01-01

While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square) and with majo......While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square...

Carbon dioxide enhances fragility of ice crystals

International Nuclear Information System (INIS)

Qin Zhao; Buehler, Markus J

2012-01-01

Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.

Reliable Exfoliation of Large-Area High-Quality Flakes of Graphene and Other Two-Dimensional Materials.

Science.gov (United States)

Huang, Yuan; Sutter, Eli; Shi, Norman N; Zheng, Jiabao; Yang, Tianzhong; Englund, Dirk; Gao, Hong-Jun; Sutter, Peter

2015-11-24

Mechanical exfoliation has been a key enabler of the exploration of the properties of two-dimensional materials, such as graphene, by providing routine access to high-quality material. The original exfoliation method, which remained largely unchanged during the past decade, provides relatively small flakes with moderate yield. Here, we report a modified approach for exfoliating thin monolayer and few-layer flakes from layered crystals. Our method introduces two process steps that enhance and homogenize the adhesion force between the outermost sheet in contact with a substrate: Prior to exfoliation, ambient adsorbates are effectively removed from the substrate by oxygen plasma cleaning, and an additional heat treatment maximizes the uniform contact area at the interface between the source crystal and the substrate. For graphene exfoliation, these simple process steps increased the yield and the area of the transferred flakes by more than 50 times compared to the established exfoliation methods. Raman and AFM characterization shows that the graphene flakes are of similar high quality as those obtained in previous reports. Graphene field-effect devices were fabricated and measured with back-gating and solution top-gating, yielding mobilities of ∼4000 and 12,000 cm(2)/(V s), respectively, and thus demonstrating excellent electrical properties. Experiments with other layered crystals, e.g., a bismuth strontium calcium copper oxide (BSCCO) superconductor, show enhancements in exfoliation yield and flake area similar to those for graphene, suggesting that our modified exfoliation method provides an effective way for producing large area, high-quality flakes of a wide range of 2D materials.

Global variations of large megathrust earthquake rupture characteristics

Science.gov (United States)

Kanamori, Hiroo

2018-01-01

Despite the surge of great earthquakes along subduction zones over the last decade and advances in observations and analysis techniques, it remains unclear whether earthquake complexity is primarily controlled by persistent fault properties or by dynamics of the failure process. We introduce the radiated energy enhancement factor (REEF), given by the ratio of an event’s directly measured radiated energy to the calculated minimum radiated energy for a source with the same seismic moment and duration, to quantify the rupture complexity. The REEF measurements for 119 large [moment magnitude (Mw) 7.0 to 9.2] megathrust earthquakes distributed globally show marked systematic regional patterns, suggesting that the rupture complexity is strongly influenced by persistent geological factors. We characterize this as the existence of smooth and rough rupture patches with varying interpatch separation, along with failure dynamics producing triggering interactions that augment the regional influences on large events. We present an improved asperity scenario incorporating both effects and categorize global subduction zones and great earthquakes based on their REEF values and slip patterns. Giant earthquakes rupturing over several hundred kilometers can occur in regions with low-REEF patches and small interpatch spacing, such as for the 1960 Chile, 1964 Alaska, and 2011 Tohoku earthquakes, or in regions with high-REEF patches and large interpatch spacing as in the case for the 2004 Sumatra and 1906 Ecuador-Colombia earthquakes. Thus, combining seismic magnitude Mw and REEF, we provide a quantitative framework to better represent the span of rupture characteristics of great earthquakes and to understand global seismicity. PMID:29750186

Enhanced magnetodielectric and multiferroic properties of Er-doped bismuth ferrite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, A.; Banerjee, M. [Department of Physics, National Institute of Technology, Durgapur 713209 (India); Basu, S., E-mail: soumen.basu@phy.nitdgp.ac.in [Department of Physics, National Institute of Technology, Durgapur 713209 (India); Mukadam, M.D.; Yusuf, S.M. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pal, M. [CSIR-Central Glass & Ceramic Research Institute, Kolkata 700032 (India)

2015-07-15

An enhancement in multiferroic properties has been achieved for chemically prepared BFO nanoparticles by doping with erbium (Er). XRD along with electron microscopy study reveals the phase purity and nanocrystalline nature of BFO. Enhancement of both the magnetic moment and resistivity is observed by virtue of Er doping. The observed enhanced magnetic moment is considered to be associated with smaller crystallite whereas increase of resistivity may be attributed to a decrease of oxygen vacancies. Doping also display an improvement of leakage behaviour and dielectric constant in nanocrystalline BFO, reflected in well-developed P-E loop. In addition, large enhancement in magnetodielectric coefficient is observed because of Er doping. Therefore, the results provide interesting approaches to improve the multiferroic properties of BFO, which has great implication towards its applications. - Highlights: • Synthesis of pure Er-doped BFO nanoparticles by chemical route. • Large increase in magnetic moment and resistivity due to Er doping. • Er doping produce well developed P-E loop and enhance polarization. • Drastic increase in dielectric constant as well as magnetodielectric coefficient observes because of Er doping.

Torsion of a nongravid uterus with a large ovarian cyst: usefulness of contrast MR image.

Science.gov (United States)

Matsumoto, Hiroki; Ohta, Tsuyoshi; Nakahara, Kenji; Kojimahara, Takanobu; Kurachi, Hirohisa

2007-01-01

Torsion of a nongravid uterus is extremely rare. Most cases of uterine torsion occur during pregnancy. Here we report a case of nongravid uterus torsion with a large adnexal mass. A 73-year-old woman presented at the emergency room with acute abdominal pain. A preoperative diagnosis of torsion of an ovarian cyst was made and laparotomy was performed. The left ovary was twisted 360 degrees in a clockwise rotation, and the uterine corpus had also undergone a 360 degrees rotation. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were carried out. Although a preoperative diagnosis of uterine torsion was not possible, it is noteworthy that in the contrast-enhanced magnetic resonance images the uterine cervix was intensely enhanced, while the uterine corpus was not. This is the first report to show the magnetic resonance imaging findings of a twisted uterus. Copyright (c) 2007 S. Karger AG, Basel.

Chain of evidence generation for contrast enhancement in digital image forensics

Science.gov (United States)

Battiato, Sebastiano; Messina, Giuseppe; Strano, Daniela

2010-01-01

The quality of the images obtained by digital cameras has improved a lot since digital cameras early days. Unfortunately, it is not unusual in image forensics to find wrongly exposed pictures. This is mainly due to obsolete techniques or old technologies, but also due to backlight conditions. To extrapolate some invisible details a stretching of the image contrast is obviously required. The forensics rules to produce evidences require a complete documentation of the processing steps, enabling the replication of the entire process. The automation of enhancement techniques is thus quite difficult and needs to be carefully documented. This work presents an automatic procedure to find contrast enhancement settings, allowing both image correction and automatic scripting generation. The technique is based on a preprocessing step which extracts the features of the image and selects correction parameters. The parameters are thus saved through a JavaScript code that is used in the second step of the approach to correct the image. The generated script is Adobe Photoshop compliant (which is largely used in image forensics analysis) thus permitting the replication of the enhancement steps. Experiments on a dataset of images are also reported showing the effectiveness of the proposed methodology.

Enhanced Graphene Photodetector with Fractal Metasurface

DEFF Research Database (Denmark)

Fan, Jieran; Wang, Di; DeVault, Clayton

2016-01-01

We designed and fabricated a broadband, polarization-independent photodetector by integrating graphene with a fractal Cayley tree metasurface. Our measurements show an almost uniform, tenfold enhancement in photocurrent generation due to the fractal metasurface structure.......We designed and fabricated a broadband, polarization-independent photodetector by integrating graphene with a fractal Cayley tree metasurface. Our measurements show an almost uniform, tenfold enhancement in photocurrent generation due to the fractal metasurface structure....

Early versus late GD-DTPA MRI enhancement in experimental glioblastomas.

Science.gov (United States)

Farace, Paolo; Tambalo, Stefano; Fiorini, Silvia; Merigo, Flavia; Daducci, Alessandro; Nicolato, Elena; Conti, Giamaica; Degrassi, Anna; Sbarbati, Andrea; Marzola, Pasquina

2011-03-01

To compare early versus late enhancement in two glioblastoma models characterized by different infiltrative/edematous patterns. Three weeks after inoculation into nude mice of U87MG and U251 cells, T1-weighted images were acquired early (10.5 min), intermediate (21 min) and late (30.5 min) after a bolus injection of Gd-DTPA at 300 μ mol/kg dosage. EARLY(TH) and LATE(TH) were the corresponding volumes with an enhancement higher than a threshold TH, defined by the mean (μ) and standard deviation (σ) on a contralateral healthy area. ADD(TH) was the enhancing volume found in LATE(TH) but not in EARLY(TH). T2 imaging of both tumors was performed, and T2 mapping of U251. In all tumors, LATE(TH) was significantly higher than EARLY(TH) for TH ranging from μ+σ to μ+5σ. The ADD(TH) /EARLY(TH) ratio was not significantly different when U251 and U87MG tumors were compared. In the U87MG tumors, some enhancement was observed outside the regularly demarcated T2-hyperintense area. In the U251 tumors, irregularly T2 demarcated, a large portion of ADD(μ+3σ) had normal T2 values. At histology, U251 showed a higher infiltrative pattern than U87MG. In these models, the increase over time in the enhancing volume did not depend on the different infiltrative/edematous patterns and was not closely related with edema. Copyright © 2011 Wiley-Liss, Inc.

Prolonged hypoxia increases survival even in Zebrafish (Danio rerio showing cardiac arrhythmia.

Directory of Open Access Journals (Sweden)

Renate Kopp

Full Text Available Tolerance towards hypoxia is highly pronounced in zebrafish. In this study even beneficial effects of hypoxia, specifically enhanced survival of zebrafish larvae, could be demonstrated. This effect was actually more pronounced in breakdance mutants, which phenotypically show cardiac arrhythmia. Breakdance mutants (bre are characterized by chronically reduced cardiac output. Despite an about 50% heart rate reduction, they become adults, but survival rate significantly drops to 40%. Normoxic bre animals demonstrate increased hypoxia inducible factor 1 a (Hif-1α expression, which indicates an activated hypoxic signaling pathway. Consequently, cardiovascular acclimation, like cardiac hypertrophy and increased erythrocyte concentration, occurs. Thus, it was hypothesized, that under hypoxic conditions survival might be even more reduced. When bre mutants were exposed to hypoxic conditions, they surprisingly showed higher survival rates than under normoxic conditions and even reached wildtype values. In hypoxic wildtype zebrafish, survival yet exceeded normoxic control values. To specify physiological acclimation, cardiovascular and metabolic parameters were measured before hypoxia started (3 dpf, when the first differences in survival rate occurred (7 dpf and when survival rate plateaued (15 dpf. Hypoxic animals expectedly demonstrated Hif-1α accumulation and consequently enhanced convective oxygen carrying capacity. Moreover, bre animals showed a significantly enhanced heart rate under hypoxic conditions, which reached normoxic wildtype values. This improvement in convective oxygen transport ensured a sufficient oxygen and nutrient supply and was also reflected in the significantly higher mitochondrial activity. The highly optimized energy metabolism observed in hypoxic zebrafish larvae might be decisive for periods of higher energy demand due to organ development, growth and increased activity. However, hypoxia increased survival only during a

Enhanced stopping of macro-particles in particle-in-cell simulations

International Nuclear Information System (INIS)

May, J.; Tonge, J.; Ellis, I.; Mori, W. B.; Fiuza, F.; Fonseca, R. A.; Silva, L. O.; Ren, C.

2014-01-01

We derive an equation for energy transfer from relativistic charged particles to a cold background plasma appropriate for finite-size particles that are used in particle-in-cell simulation codes. Expressions for one-, two-, and three-dimensional particles are presented, with special attention given to the two-dimensional case. This energy transfer is due to the electric field of the wake set up in the background plasma by the relativistic particle. The enhanced stopping is dependent on the q 2 /m, where q is the charge and m is the mass of the relativistic particle, and therefore simulation macro-particles with large charge but identical q/m will stop more rapidly. The stopping power also depends on the effective particle shape of the macro-particle. These conclusions are verified in particle-in-cell simulations. We present 2D simulations of test particles, relaxation of high-energy tails, and integrated fast ignition simulations showing that the enhanced drag on macro-particles may adversely affect the results of these simulations in a wide range of high-energy density plasma scenarios. We also describe a particle splitting algorithm which can potentially overcome this problem and show its effect in controlling the stopping of macro-particles

Detectability of hepatocellular carcinoma: comparison of Gd-DTPA-enhanced and SPIO-enhanced MR imaging

International Nuclear Information System (INIS)

Kwak, Hyo Sung; Lee, Jeong Min; Kim In Hwan; Kim, Chong Soo; Han, Hyeun Young; Yoon, Kwon ha; Shin, Kyung Sook

2000-01-01

To compare the detectability of hepatocellular carcinoma (HCC) using superparamagnetic iron oxide (SPIO)-enhanced T2-weighted turbo spin echo (TSE), SPIO-enhanced T2-weighted FISP, and dynamic Gd-DTPA-enhanced fast low-angle shot (FLASH) MR images. In order to assess their hepatic lesions, 25 patients (20 men and 5 women) with HCC were enrolled in an MR study in which both gadolinium and Spiro were used. Since the lesions were most conspicuous during the phase of dynamic arterial dominant phase of dynamic gadolinium-enhanced imaging, this was the phase used for analysis. Images were analyzed qualitatively and quantitatively, and to compare the diagnostic value of gadolinium-enhanced imaging with that of SPIO-enhanced imaging for the detection of HCCs, a receiver-operated characteristic curve was obtained. Qualitative analysis revealed a significantly higher percentage of signal loss and a higher liver-lesion contrast-to-noise ratio on SPIO-enhanced FISP imaging than on SPIO-enhanced T2-weighted TSE imaging (p less than 0.05). It also showed that the lesions were most clearly visible on SPIO-enhanced FISP imaging (and significantly so), followed by SPIO-enhanced T2-weighted TSE imaging, and dynamic gadolinium-enhanced imaging. Imaging artifacts were more prominent on SPIO-enhanced T2-weighted TSE than on SPIO-enhanced PISF imaging or dynamic gadolinium-enhanced imaging (p less than 0.05). According to ROC analysis, SPIO-enhanced T2-weighted turbo spin echo (TSE) or SPIO-enhanced FISP imaging achieved higher accuracy than did dynamic gadolinium-enhanced FLASH imaging (p less than 0.05). For the detection of hepatocellular carcinomas, SPIO-enhanced MR imaging is better than gadolinium-enhanced FLASH imaging

Interplay between cooperation-enhancing mechanisms in evolutionary games with tag-mediated interactions

Science.gov (United States)

Hadzibeganovic, Tarik; Stauffer, Dietrich; Han, Xiao-Pu

2018-04-01

Cooperation is fundamental for the long-term survival of biological, social, and technological networks. Previously, mechanisms for the enhancement of cooperation, such as network reciprocity, have largely been studied in isolation and with often inconclusive findings. Here, we present an evolutionary, multiagent-based, and spatially explicit computer model to specifically address the interactive interplay between such mechanisms. We systematically investigate the effects of phenotypic diversity, network structure, and rewards on cooperative behavior emerging in a population of reproducing artificial decision makers playing tag-mediated evolutionary games. Cooperative interactions are rewarded such that both the benefits of recipients and costs of donators are affected by the reward size. The reward size is determined by the number of cooperative acts occurring within a given reward time frame. Our computational experiments reveal that small reward frames promote unconditional cooperation in populations with both low and high diversity, whereas large reward frames lead to cycles of conditional and unconditional strategies at high but not at low diversity. Moreover, an interaction between rewards and spatial structure shows that relative to small reward frames, there is a strong difference between the frequency of conditional cooperators populating rewired versus non-rewired networks when the reward frame is large. Notably, in a less diverse population, the total number of defections is comparable across different network topologies, whereas in more diverse environments defections become more frequent in a regularly structured than in a rewired, small-world network of contacts. Acknowledging the importance of such interaction effects in social dilemmas will have inevitable consequences for the future design of cooperation-enhancing protocols in large-scale, distributed, and decentralized systems such as peer-to-peer networks.

Enhancement of the facial nerve at MR imaging

International Nuclear Information System (INIS)

Gebarski, S.S.; Telian, S.; Niparko, J.

1990-01-01

In the few cases studied, normal facial nerves are reported to show no MR enhancement. Because this did not fit clinical experience, the authors designed a retrospective imaging review with anatomic correlation. Between June 1989 and June 1990, 175 patients underwent focused temporal bone MR imaging before and after administration of intravenous gadopentetate dimeglumine (0.1 mmol/kg). Exclusion criteria for the study included facial nerve dysfunction (subjective or objective); facial nerve mass; central nervous system infection, inflammation, or trauma; neurofibromatosis; or previous cranial surgery of any type. The following sequences were reviewed: GE 1.5-T axial spin-echo TR 567 msec, TE 20 msec, 256 x 192, 2.0 excitations, 20-cm field of view, 3-mm section thickness. Imaging analysis was a side-by side comparison of the images and region-of-interest quantified signal intensity. Anatomic correlation included a comparison with dissection and axial histologic sections. Ninety-three patients (aged 15-75 years) were available for imaging analysis after the exclusionary criteria were applied. With 46 patients (92 facial nerves) analyzed, they found that 76 nerves (83%) showed easily visible gadopentetate dimeglumine enhancement, especially about the geniculate ganglia. Sixteen (17%) of the 92 nerves did not show visible enhancement, but region-of-interest analysis showed increased intensity after gadopentetate dimeglumine administration. Sixteen patients (42%) showed right-to-left asymmetry in facial nerve enhancement. The facial nerves showed enhancement in the geniculate, tympanic, and fallopian portions; the facial nerve within the IAC showed no enhancement. This corresponded exactly with the topographic features of a circummeural arterial/venous plexus seen on the anatomic preparations

Enhancing recovery of recombinant hepatitis B surface antigen in lab-scale and large-scale anion-exchange chromatography by optimizing the conductivity of buffers.

Science.gov (United States)

Mojarrad Moghanloo, Gol Mohammad; Khatami, Maryam; Javidanbardan, Amin; Hosseini, Seyed Nezamedin

2018-01-01

In biopharmaceutical science, ion-exchange chromatography (IEC) is a well-known purification technique to separate the impurities such as host cell proteins from recombinant proteins. However, IEC is one of the limiting steps in the purification process of recombinant hepatitis B surface antigen (rHBsAg), due to its low recovery rate (rate of 82% in both lab-scale and large-scale weak anion-exchange chromatography without any harsh effect on the purity percentage of rHBsAg. The recovery enhancement via increasing the conductivity of Eq. and Wash. buffers can be explained by their roles in reducing the binding strength and aggregation of retained particles in the column. Moreover, further increase in the salt concentration of Elut. Buffer could substantially promote the ion exchange process and the elution of retained rHBsAg. Copyright © 2017 Elsevier Inc. All rights reserved.

Largely enhanced dielectric properties of carbon nanotubes/polyvinylidene fluoride binary nanocomposites by loading a few boron nitride nanosheets

International Nuclear Information System (INIS)

Yang, Minhao; Zhao, Hang; He, Delong; Bai, Jinbo

2016-01-01

The ternary nanocomposites of boron nitride nanosheets (BNNSs)/carbon nanotubes (CNTs)/polyvinylidene fluoride (PVDF) are fabricated via a combination of solution casting and extrusion-injection processes. The effects of BNNSs on the electrical conductivity, dielectric behavior, and microstructure changes of CNTs/PVDF binary nanocomposites are systematically investigated. A low percolation value (f_c) for the CNTs/PVDF binary system is obtained due to the integration of solution and melting blending procedures. Two kinds of CNTs/PVDF binary systems with various CNTs contents (f_C_N_T_s) as the matrix are discussed. The results reveal that compared with CNTs/PVDF binary systems at the same f_C_N_T_s, the ternary BNNSs/CNTs/PVDF nanocomposites exhibit largely enhanced dielectric properties due to the improvement of the CNTs dispersion state and the conductive network. The dielectric constant of CNTs/PVDF binary nanocomposite with 6 vol. % CNTs (f_C_N_T_s   f_c), it displays a 43.32% improvement from 1325 to 1899 after the addition of 3 vol. % BNNSs. The presence of BNNSs facilitates the formation of the denser conductive network. Meanwhile, the ternary BNNSs/CNTs/PVDF systems exhibit a low dielectric loss. The adjustable dielectric properties could be obtained by employing the ternary systems due to the microstructure changes of nanocomposites.

The large N limit of superconformal field theories and supergravity

International Nuclear Information System (INIS)

Maldacena, J.

1999-01-01

We show that the large N limit of certain conformal field theories in various dimensions include in their Hilbert space a sector describing supergravity on the product of Anti-deSitter spacetimes, spheres and other compact manifolds. This is shown by taking some branes in the full M/string theory and then taking a low energy limit where the field theory on the brane decouples from the bulk. We observe that, in this limit, we can still trust the near horizon geometry for large N. The enhanced supersymmetries of the near horizon geometry correspond to the extra supersymmetry generators present in the superconformal group (as opposed to just the super-Poincare group). The close-quote t Hooft limit of 3+1N=4 super-Yang-Mills at the conformal point is shown to contain strings: they are IIB strings. We conjecture that compactifications of M/string theory on various Anti-deSitter spacetimes is dual to various conformal field theories. This leads to a new proposal for a definition of M-theory which could be extended to include five non-compact dimensions. copyright 1999 American Institute of Physics

Tomato Fruits Show Wide Phenomic Diversity but Fruit Developmental Genes Show Low Genomic Diversity.

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Vijee Mohan

Full Text Available Domestication of tomato has resulted in large diversity in fruit phenotypes. An intensive phenotyping of 127 tomato accessions from 20 countries revealed extensive morphological diversity in fruit traits. The diversity in fruit traits clustered the accessions into nine classes and identified certain promising lines having desirable traits pertaining to total soluble salts (TSS, carotenoids, ripening index, weight and shape. Factor analysis of the morphometric data from Tomato Analyzer showed that the fruit shape is a complex trait shared by several factors. The 100% variance between round and flat fruit shapes was explained by one discriminant function having a canonical correlation of 0.874 by stepwise discriminant analysis. A set of 10 genes (ACS2, COP1, CYC-B, RIN, MSH2, NAC-NOR, PHOT1, PHYA, PHYB and PSY1 involved in various plant developmental processes were screened for SNP polymorphism by EcoTILLING. The genetic diversity in these genes revealed a total of 36 non-synonymous and 18 synonymous changes leading to the identification of 28 haplotypes. The average frequency of polymorphism across the genes was 0.038/Kb. Significant negative Tajima'D statistic in two of the genes, ACS2 and PHOT1 indicated the presence of rare alleles in low frequency. Our study indicates that while there is low polymorphic diversity in the genes regulating plant development, the population shows wider phenotype diversity. Nonetheless, morphological and genetic diversity of the present collection can be further exploited as potential resources in future.

Raman enhancement on ultra-clean graphene quantum dots produced by quasi-equilibrium plasma-enhanced chemical vapor deposition.

Science.gov (United States)

Liu, Donghua; Chen, Xiaosong; Hu, Yibin; Sun, Tai; Song, Zhibo; Zheng, Yujie; Cao, Yongbin; Cai, Zhi; Cao, Min; Peng, Lan; Huang, Yuli; Du, Lei; Yang, Wuli; Chen, Gang; Wei, Dapeng; Wee, Andrew Thye Shen; Wei, Dacheng

2018-01-15

Graphene is regarded as a potential surface-enhanced Raman spectroscopy (SERS) substrate. However, the application of graphene quantum dots (GQDs) has had limited success due to material quality. Here, we develop a quasi-equilibrium plasma-enhanced chemical vapor deposition method to produce high-quality ultra-clean GQDs with sizes down to 2 nm directly on SiO 2 /Si, which are used as SERS substrates. The enhancement factor, which depends on the GQD size, is higher than conventional graphene sheets with sensitivity down to 1 × 10 -9  mol L -1 rhodamine. This is attributed to the high-quality GQDs with atomically clean surfaces and large number of edges, as well as the enhanced charge transfer between molecules and GQDs with appropriate diameters due to the existence of Van Hove singularities in the electronic density of states. This work demonstrates a sensitive SERS substrate, and is valuable for applications of GQDs in graphene-based photonics and optoelectronics.

Enhanced Raman scattering assisted by ultrahigh order modes of the double metal cladding waveguide

Energy Technology Data Exchange (ETDEWEB)

Xu, Tian; Huang, Liming; Jin, Yonglong; Fang, Jinghuai, E-mail: cyin.phys@gmail.com, E-mail: fjhuai@ntu.edu.cn [Physics Department, Nantong University, No. 9, Seyuan Road, Nantong, Jiangsu 226007 (China); Yin, Cheng, E-mail: cyin.phys@gmail.com, E-mail: fjhuai@ntu.edu.cn [Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology, Hohai University, Changzhou 213022 (China); Huang, Meizhen [Department of Instrument Science and Engineering, Shanghai Jiaotong University, No. 800, DongChuan Road, Shanghai 200240 (China)

2014-10-20

Distinguished from the usual strategy to enhance the Raman scattering such as creating hot spots in the surface-enhanced Raman scattering, this paper takes a quite different approach based on the double metal cladding waveguide. The target analyte is located in the guiding layer of sub-millimeter scale, where several ultrahigh order modes with high intensity are simultaneously excited via a focused laser beam. The experimental setup is simple, and both simulation and experimental results confirm the enhancement mechanism of these oscillating modes. Other appealing features include the large detection area and the ability to excite guided modes via both polarizations. This scheme can be applied to large molecules detection and readily integrated with other Raman enhancement techniques.

Enhancements to Constrained Novelty Search: Two-Population Novelty Search for Generating Game Content

DEFF Research Database (Denmark)

Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

2013-01-01

pop genetic algorithm. These algorithms are applied to the problem of creating diverse and feasible game levels, representative of a large class of important problems in procedural content generation for games. Results show that the new algorithms under certain conditions can produce larger and more...... diverse sets of feasible strategy game maps than existing algorithms. However, the best algorithm is contingent on the particularities of the search space and the genetic operators used. It is also shown that the proposed enhancement of offspring boosting increases performance in all cases....

Accelerating the carbon cycle: the ethics of enhanced weathering.

Science.gov (United States)

Lawford-Smith, H; Currie, A

2017-04-01

Enhanced weathering, in comparison to other geoengineering measures, creates the possibility of a reduced cost, reduced impact way of decreasing atmospheric carbon, with positive knock-on effects such as decreased oceanic acidity. We argue that ethical concerns have a place alongside empirical, political and social factors as we consider how to best respond to the critical challenge that anthropogenic climate change poses. We review these concerns, considering the ethical issues that arise (or would arise) in the large-scale deployment of enhanced weathering. We discuss post-implementation scenarios, failures of collective action, the distribution of risk and externalities and redress for damage. We also discuss issues surrounding 'dirty hands' (taking conventionally immoral action to avoid having to take action that is even worse), whether enhanced weathering research might present a moral hazard, the importance of international governance and the notion that the implementation of large-scale enhanced weathering would reveal problematic hubris. Ethics and scientific research interrelate in complex ways: some ethical considerations caution against research and implementation, while others encourage them. Indeed, the ethical perspective encourages us to think more carefully about how, and what types of, geoengineering should be researched and implemented. © 2017 The Author(s).

Holes generation in glass using large spot femtosecond laser pulses

Science.gov (United States)

Berg, Yuval; Kotler, Zvi; Shacham-Diamand, Yosi

2018-03-01

We demonstrate high-throughput, symmetrical, holes generation in fused silica glass using a large spot size, femtosecond IR-laser irradiation which modifies the glass properties and yields an enhanced chemical etching rate. The process relies on a balanced interplay between the nonlinear Kerr effect and multiphoton absorption in the glass which translates into symmetrical glass modification and increased etching rate. The use of a large laser spot size makes it possible to process thick glasses at high speeds over a large area. We have demonstrated such fabricated holes with an aspect ratio of 1:10 in a 1 mm thick glass samples.

Large Aspect Ratio Tokamak Study

International Nuclear Information System (INIS)

Reid, R.L.; Holmes, J.A.; Houlberg, W.A.; Peng, Y.K.M.; Strickler, D.J.; Brown, T.G.; Wiseman, G.W.

1980-06-01

The Large Aspect Ratio Tokamak Study (LARTS) at Oak Ridge National Laboratory (ORNL) investigated the potential for producing a viable longburn tokamak reactor by enhancing the volt-second capability of the ohmic heating transformer through the use of high aspect ratio designs. The plasma physics, engineering, and economic implications of high aspect ratio tokamaks were assessed in the context of extended burn operation. Using a one-dimensional transport code plasma startup and burn parameters were addressed. The pulsed electrical power requirements for the poloidal field system, which have a major impact on reactor economics, were minimized by optimizing the startup and shutdown portions of the tokamak cycle. A representative large aspect ratio tokamak with an aspect ratio of 8 was found to achieve a burn time of 3.5 h at capital cost only approx. 25% greater than that of a moderate aspect ratio design tokamak

Support of large taxpayers foreign experience and its actuality for Ukraine

Directory of Open Access Journals (Sweden)

O.S. Vatamaniuk

2016-12-01

Full Text Available The article deals with the features of foreign experience of support of large taxpayers considering its actuality for Ukraine in terms of harmonization of relations between fiscal authorities and taxpayers. The key characteristics of the models of functioning of large taxpayers’ units in Australia, Great Britain, Norway and the Netherlands are identified.The attention is focused on the application of risk-based approach to servicing large taxpayers in the Australian Taxation Office. The activities of the Large Business directorate in the UK and the preconditions of its effectiveness are clarified. The horizontal monitoring peculiarities of large taxpayers in the Netherlands are revealed. The advantages of implementing an enhanced dialogue with large taxpayers and the need for introduction of risk-based methods to supporting large taxpayers in Ukraine are substantiated.

Enhanced photovoltaic currents in strained Fe-doped LiNbO{sub 3} films

Energy Technology Data Exchange (ETDEWEB)

Inoue, Ryotaro [Division of Physics, Institute of Liberal Education, School of Medicine, Nihon University, 31-10, Ooyaguchi-kamicho, Itabashi-ku, Tokyo 173-8601 (Japan); Takahashi, Shusuke; Kitanaka, Yuuki; Oguchi, Takeshi; Noguchi, Yuji; Miyayama, Masaru [Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan)

2015-12-15

We investigate the impact of strain on photovoltaic current (J{sub z}) characteristics for iron-doped LiNbO{sub 3} (Fe-LN) under visible light illumination by thin-film experiments. The J{sub z} values are demonstrated to be dramatically enhanced for the film with a tensile strain along the P{sub s} direction, which is over 500 times as large as that of the bulk (strain-free) Fe-LN crystals. Density functional theory (DFT) calculations show that the tensile strain increases an off-center displacement of Fe{sup 2+} that is opposite to the P{sub s} direction. Our experimental and DFT study demonstrates that the control of the lattice strain is effective in enhancing the photovoltaic effect in the Fe-LN system. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Pumilio2-deficient mice show a predisposition for epilepsy

Directory of Open Access Journals (Sweden)

Philipp Follwaczny

2017-11-01

Full Text Available Epilepsy is a neurological disease that is caused by abnormal hypersynchronous activities of neuronal ensembles leading to recurrent and spontaneous seizures in human patients. Enhanced neuronal excitability and a high level of synchrony between neurons seem to trigger these spontaneous seizures. The molecular mechanisms, however, regarding the development of neuronal hyperexcitability and maintenance of epilepsy are still poorly understood. Here, we show that pumilio RNA-binding family member 2 (Pumilio2; Pum2 plays a role in the regulation of excitability in hippocampal neurons of weaned and 5-month-old male mice. Almost complete deficiency of Pum2 in adult Pum2 gene-trap mice (Pum2 GT causes misregulation of genes involved in neuronal excitability control. Interestingly, this finding is accompanied by the development of spontaneous epileptic seizures in Pum2 GT mice. Furthermore, we detect an age-dependent increase in Scn1a (Nav1.1 and Scn8a (Nav1.6 mRNA levels together with a decrease in Scn2a (Nav1.2 transcript levels in weaned Pum2 GT that is absent in older mice. Moreover, field recordings of CA1 pyramidal neurons show a tendency towards a reduced paired-pulse inhibition after stimulation of the Schaffer-collateral-commissural pathway in Pum2 GT mice, indicating a predisposition to the development of spontaneous seizures at later stages. With the onset of spontaneous seizures at the age of 5 months, we detect increased protein levels of Nav1.1 and Nav1.2 as well as decreased protein levels of Nav1.6 in those mice. In addition, GABA receptor subunit alpha-2 (Gabra2 mRNA levels are increased in weaned and adult mice. Furthermore, we observe an enhanced GABRA2 protein level in the dendritic field of the CA1 subregion in the Pum2 GT hippocampus. We conclude that altered expression levels of known epileptic risk factors such as Nav1.1, Nav1.2, Nav1.6 and GABRA2 result in enhanced seizure susceptibility and manifestation of epilepsy in the

Laser writing of single-crystalline gold substrates for surface enhanced Raman spectroscopy

Science.gov (United States)

Singh, Astha; Sharma, Geeta; Ranjan, Neeraj; Mittholiya, Kshitij; Bhatnagar, Anuj; Singh, B. P.; Mathur, Deepak; Vasa, Parinda

2017-07-01

Surface enhanced Raman scattering (SERS) spectroscopy, a powerful contemporary tool for studying low-concentration analytes via surface plasmon induced enhancement of local electric field, is of utility in biochemistry, material science, threat detection, and environmental studies. We have developed a simple, fast, scalable, and relatively low-cost optical method of fabricating and characterizing large-area, reusable and broadband SERS substrates with long storage lifetime. We use tightly focused, intense infra-red laser pulses to write gratings on single-crystalline, Au (1 1 1) gold films on mica which act as SERS substrates. Our single-crystalline SERS substrates compare favourably, in terms of surface quality and roughness, to those fabricated in poly-crystalline Au films. Tests show that our SERS substrates have the potential of detecting urea and 1,10-phenantroline adulterants in milk and water, respectively, at 0.01 ppm (or lower) concentrations.

The Most Metal-poor Stars in the Large Magellanic Cloud

Science.gov (United States)

Schlaufman, Kevin C.

2018-06-01

The chemical abundances of the most metal-poor stars in a galaxy can be used to investigate the earliest stages of its formation and chemical evolution. Differences between the abundances of the most metal-poor stars in the Milky Way and in its satellite dwarf galaxies have been noted and provide the strongest available constraints on the earliest stages of general galactic chemical evolution models. However, the masses of the Milky Way and its satellite dwarf galaxies differ by four orders of magnitude, leaving a gap in our knowledge of the early chemical evolution of intermediate mass galaxies like the Magellanic Clouds. To close that gap, we have initiated a survey of the metal-poor stellar populations of the Magellanic Clouds using the mid-infrared metal-poor star selection of Schlaufman & Casey (2014). We have discovered the three most metal-poor giant stars known in the Large Magellanic Cloud (LMC) and reobserved the previous record holder. The stars have metallicities in the range -2.70 < [Fe/H] < -2.00 and three show r-process enhancement: one has [Eu II/Fe] = +1.65 and two others have [Eu II/Fe] = +0.65. The probability that four randomly selected very metal-poor stars in the halo of the Milky Way are as r-process enhanced is 0.0002. For that reason, the early chemical enrichment of the heaviest elements in the LMC and Milky Way were qualitatively different. It is also suggestive of a possible chemical link between the LMC and the ultra-faint dwarf galaxies nearby with evidence of r-process enhancement (e.g., Reticulum II and Tucana III). Like Reticulum II, the most metal-poor star in our LMC sample is the only one not enhanced in r-process elements.

Imprint of thawing scalar fields on the large scale galaxy overdensity

Science.gov (United States)

Dinda, Bikash R.; Sen, Anjan A.

2018-04-01

We investigate the observed galaxy power spectrum for the thawing class of scalar field models taking into account various general relativistic corrections that occur on very large scales. We consider the full general relativistic perturbation equations for the matter as well as the dark energy fluid. We form a single autonomous system of equations containing both the background and the perturbed equations of motion which we subsequently solve for different scalar field potentials. First we study the percentage deviation from the Λ CDM model for different cosmological parameters as well as in the observed galaxy power spectra on different scales in scalar field models for various choices of scalar field potentials. Interestingly the difference in background expansion results from the enhancement of power from Λ CDM on small scales, whereas the inclusion of general relativistic (GR) corrections results in the suppression of power from Λ CDM on large scales. This can be useful to distinguish scalar field models from Λ CDM with future optical/radio surveys. We also compare the observed galaxy power spectra for tracking and thawing types of scalar field using some particular choices for the scalar field potentials. We show that thawing and tracking models can have large differences in observed galaxy power spectra on large scales and for smaller redshifts due to different GR effects. But on smaller scales and for larger redshifts, the difference is small and is mainly due to the difference in background expansion.

Enhanced saturated fatty acids accumulation in cultures of newly-isolated strains of Schizochytrium sp. and Thraustochytriidae sp. for large-scale biodiesel production.

Science.gov (United States)

Wang, Qiuzhen; Sen, Biswarup; Liu, Xianhua; He, Yaodong; Xie, Yunxuan; Wang, Guangyi

2018-08-01

Heterotrophic marine protists (Thraustochytrids) have received increasingly global attention as a renewable, sustainable and alternative source of biodiesel because of their high ability of saturated fatty acids (SFAs) accumulation. Yet, the influence of extrinsic factors (nutrients and environmental conditions) on thraustochytrid culture and optimal conditions for high SFAs production are poorly described. In the present study, two different thraustochytrid strains, Schizochytrium sp. PKU#Mn4 and Thraustochytriidae sp. PKU#Mn16 were studied for their growth and SFAs production profiles under various conditions (carbon, nitrogen, temperature, pH, KH 2 PO 4 , salinity, and agitation speed). Of the culture conditions, substrates (C and N) source and conc., temperature, and agitation speed significantly influenced the cell growth and SFAs production of both strains. Although both the strains were capable of growth and SFAs production in the broad range of culture conditions, their physiological responses to KH 2 PO 4 , pH, and salinity were dissimilar. Under their optimal batch culture conditions, peak SFAs productions of 3.3g/L and 2.2g/L with 62% and 49% SFAs contents (relative to total fatty acids) were achieved, respectively. The results of 5-L fed-batch fermentation under optimal conditions showed a nearly 4.5-fold increase in SFAs production (i.e., 7.5g/L) by both strains compared to unoptimized conditions. Of the two strains, the quality of biodiesel produced from the fatty acids of PKU#Mn4 met the biodiesel standard defined by ASTM6751. This study, to the knowledge of the authors, is the first comprehensive report of optimal fermentation conditions demonstrating enhanced SFAs production by strains belonging to two different thraustochytrid genera and provides the basis for large-scale biodiesel production. Copyright © 2018. Published by Elsevier B.V.

Development of bubble chambers with enhanced stability and sensitivity to low-energy nuclear recoils

International Nuclear Information System (INIS)

Bolte, W.J.; Collar, J.I.; Crisler, M.; Hall, J.; Holmgren, D.; Nakazawa, D.; Odom, B.; O'Sullivan, K.; Plunkett, R.; Ramberg, E.; Raskin, A.; Sonnenschein, A.; Vieira, J.D.

2007-01-01

The viability of using Bubble Chambers as dark matter particle detectors is considered. Techniques leading to the enhanced chamber stability needed for this new application are described in detail. Prototype trials show that sensitivity to the low-energy nuclear recoils induced by Weakly Interacting Massive Particles (WIMP) is possible in conditions of extreme insensitivity to minimum ionizing backgrounds. An understanding of detector response is demonstrated using existing theoretical models. We briefly comment on the prospects for detection of supersymmetric dark matter with large CF 3 I chambers

Contrast enhanced CT of spinal cord angioma

International Nuclear Information System (INIS)

Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

1982-01-01

Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

Neurostimulation for Memory Enhancement in Epilepsy.

Science.gov (United States)

Meisenhelter, Stephen; Jobst, Barbara C

2018-04-19

Memory is one of the top concerns of epilepsy patients, but there are no known treatments to directly alleviate the memory deficits associated with epilepsy. Neurostimulation may provide new therapeutic tools to enhance memory in epilepsy patients. Here, we critically review recent investigations of memory enhancement using transcranial electrical stimulation (tES), transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), chronic intracranial stimulation, and acute intracranial stimulation. Existing literature suggests that transcranial direct current stimulation (tDCS) produces a small enhancement in memory in neuropsychological patients, but transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) have not been found to have an effect on memory. Most studies of transcranial magnetic stimulation (TMS) have found that TMS has no positive effect on memory. Vagus nerve stimulation can acutely enhance memory, while chronic therapy does not appear to alter memory performance. We found that there is the most evidence for significant memory enhancement using intracranial stimulation techniques, especially chronic stimulation of the fornix and task-responsive stimulation of the lateral temporal lobe. Presently, there are no existing therapeutic options for directly treating epilepy-related memory deficits. While neurostimulation technologies for memory enhancement are largely still in the experimental phase, neurostimulation appears promising as a future technique for treating epilepsy-related memory deficits.

Enhancement effect of irradiation by methotrexate

International Nuclear Information System (INIS)

Shehata, W.M.; Meyer, R.L.

1980-01-01

Three cases are described in which complications developed which were believed to be due to the enhancement effect of irradiation by methotrexate during the course of therapy for lung, kidney, and bladder cancer. These included esophageal and large bowel complications. In two of these cases, the patients improved with conservative therapy

Bi-Histogram Equalization with Brightnes Preservation Using Contras Enhancement

OpenAIRE

A. Anitha Rani; Gowthami Rajagopal; A. Jagadeswaran

2014-01-01

Contrast enhancement is an important factor in the image preprocesing step. One of the widely acepted contrast enhancement method is the histogram equalization. Although histogram equalization achieves comparatively beter performance on almost al types of image, global histogram equalization sometimes produces excesive visual deterioration. A new extension of bi- histogram equalization caled Bi-Histogram Equalization with Neighborhod Metric (BHENM). First, large histogram bins that cause w...

Enhancement of sludge granulation in anaerobic treatment of concentrated latex wastewater

Directory of Open Access Journals (Sweden)

Nugul Intrasungkha

2008-04-01

Full Text Available Recently, the upflow anaerobic sludge blanket (UASB reactor has become attractive for wastewater treatment with low energy requirement and biogas production. However, the start-up of an UASB reactor depends on the formation of granules. Therefore, this research aims to study the effect of AlCl3, CaCl2 and temperature on the granule formation process using real concentrated latex wastewater. The result shows that the optimum chemicals concentration of AlCl3 at 300 mg/l enhanced the biomass accumulation and sludge formation process. Approximately 50% of large granular size (0.5 mm 0.8 mm within 35 days, whereas the large granular sizes in reactorwithout AlCl3 supplement (R2 became visible within 63 days. Moreover, this experiment found that R1, R2 and R3 could reach steady state within 40, 55 and 45 days, respectively.

Bat Accelerated Regions Identify a Bat Forelimb Specific Enhancer in the HoxD Locus.

Directory of Open Access Journals (Sweden)

Betty M Booker

2016-03-01

Full Text Available The molecular events leading to the development of the bat wing remain largely unknown, and are thought to be caused, in part, by changes in gene expression during limb development. These expression changes could be instigated by variations in gene regulatory enhancers. Here, we used a comparative genomics approach to identify regions that evolved rapidly in the bat ancestor, but are highly conserved in other vertebrates. We discovered 166 bat accelerated regions (BARs that overlap H3K27ac and p300 ChIP-seq peaks in developing mouse limbs. Using a mouse enhancer assay, we show that five Myotis lucifugus BARs drive gene expression in the developing mouse limb, with the majority showing differential enhancer activity compared to the mouse orthologous BAR sequences. These include BAR116, which is located telomeric to the HoxD cluster and had robust forelimb expression for the M. lucifugus sequence and no activity for the mouse sequence at embryonic day 12.5. Developing limb expression analysis of Hoxd10-Hoxd13 in Miniopterus natalensis bats showed a high-forelimb weak-hindlimb expression for Hoxd10-Hoxd11, similar to the expression trend observed for M. lucifugus BAR116 in mice, suggesting that it could be involved in the regulation of the bat HoxD complex. Combined, our results highlight novel regulatory regions that could be instrumental for the morphological differences leading to the development of the bat wing.

Clouds enhance Greenland ice sheet mass loss

Science.gov (United States)

Van Tricht, Kristof; Gorodetskaya, Irina V.; L'Ecuyer, Tristan; Lenaerts, Jan T. M.; Lhermitte, Stef; Noel, Brice; Turner, David D.; van den Broeke, Michiel R.; van Lipzig, Nicole P. M.

2015-04-01

Clouds have a profound influence on both the Arctic and global climate, while they still represent one of the key uncertainties in climate models, limiting the fidelity of future climate projections. The potentially important role of thin liquid-containing clouds over Greenland in enhancing ice sheet melt has recently gained interest, yet current research is spatially and temporally limited, focusing on particular events, and their large scale impact on the surface mass balance remains unknown. We used a combination of satellite remote sensing (CloudSat - CALIPSO), ground-based observations and climate model (RACMO) data to show that liquid-containing clouds warm the Greenland ice sheet 94% of the time. High surface reflectivity (albedo) for shortwave radiation reduces the cloud shortwave cooling effect on the absorbed fluxes, while not influencing the absorption of longwave radiation. Cloud warming over the ice sheet therefore dominates year-round. Only when albedo values drop below ~0.6 in the coastal areas during summer, the cooling effect starts to overcome the warming effect. The year-round excess of energy due to the presence of liquid-containing clouds has an extensive influence on the mass balance of the ice sheet. Simulations using the SNOWPACK snow model showed not only a strong influence of these liquid-containing clouds on melt increase, but also on the increased sublimation mass loss. Simulations with the Community Earth System Climate Model for the end of the 21st century (2080-2099) show that Greenland clouds contain more liquid water path and less ice water path. This implies that cloud radiative forcing will be further enhanced in the future. Our results therefore urge the need for improving cloud microphysics in climate models, to improve future projections of ice sheet mass balance and global sea level rise.

Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

International Nuclear Information System (INIS)

Kim, Hyun Su; Kim, Seong Hyun; Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil; Park, Cheol Keun

2015-01-01

Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm 2 were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP images

Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Su [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kim, Seong Hyun, E-mail: kshyun@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Park, Cheol Keun [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710 (Korea, Republic of)

2015-04-15

Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm{sup 2} were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP

Enhanced self-magnetic field by atomic polarization in partially stripped plasma produced by a short and intense laser pulse

International Nuclear Information System (INIS)

Hu Qianglin; Liu Shibing; Jiang, Y.J.; Zhang Jie

2005-01-01

The enhancement and redistribution of a self-generated quasistatic magnetic field, due to the presence of the polarization field induced by partially ionized atoms, are analytically revealed when a linearly polarized intense and short pulse laser propagates in a partially stripped plasma with higher density. In particular, the shorter wavelength of the laser pulse can evidently intensify the amplitude of the magnetic field. These enhancement and redistribution of the magnetic field are considered physically as a result of the competition of the electrostatic field (electron-ion separation) associated with the plasma wave, the atomic polarization field, and the pondoromotive potential associated with the laser field. This competition leads to the generation of a positive, large amplitude magnetic field in the zone of the pulse center, which forms a significant difference in partially and fully stripped plasmas. The numerical result shows further that the magnetic field is resonantly modulated by the plasma wave when the pulse length is the integer times the plasma wavelength. This apparently implies that the further enhancement and restructure of the large amplitude self-magnetic field can evidently impede the acceleration and stable transfer of the hot-electron beam

Show-Bix &

DEFF Research Database (Denmark)

2014-01-01

The anti-reenactment 'Show-Bix &' consists of 5 dias projectors, a dial phone, quintophonic sound, and interactive elements. A responsive interface will enable the Dias projectors to show copies of original dias slides from the Show-Bix piece ”March på Stedet”, 265 images in total. The copies are...

Enhanced-locality fiber-optic two-photon-fluorescence live-brain interrogation

Energy Technology Data Exchange (ETDEWEB)

Fedotov, I. V.; Doronina-Amitonova, L. V. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Kurchatov Institute National Research Center, Moscow (Russian Federation); Sidorov-Biryukov, D. A.; Fedotov, A. B. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Anokhin, K. V. [Kurchatov Institute National Research Center, Moscow (Russian Federation); P.K. Anokhin Institute of Normal Physiology, Russian Academy of Medical Sciences, Moscow (Russian Federation); Kilin, S. Ya. [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus); Sakoda, K. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Zheltikov, A. M. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Department of Physics and Astronomy, Texas A and M University, College Station, Texas 77843 (United States); Center of Photochemistry, Russian Academy of Sciences, ul. Novatorov 7a, Moscow 117421 (Russian Federation)

2014-02-24

Two-photon excitation is shown to substantially enhance the locality of fiber-based optical interrogation of strongly scattering biotissues. In our experiments, a high-numerical-aperture, large-core-are fiber probe is used to deliver the 200-fs output of a 100-MHz mode-locked ytterbium fiber laser to samples of live mouse brain, induce two-photon fluorescence of nitrogen–vacancy centers in diamond markers in brain sample. Fiber probes with a high numerical aperture and a large core area are shown to enable locality enhancement in fiber-laser–fiber-probe two-photon brain excitation and interrogation without sacrificing the efficiency of fluorescence response collection.

Rhesus monkeys (Macaca mulatta) show robust primacy and recency in memory for lists from small, but not large, image sets.

Science.gov (United States)

Basile, Benjamin M; Hampton, Robert R

2010-02-01

The combination of primacy and recency produces a U-shaped serial position curve typical of memory for lists. In humans, primacy is often thought to result from rehearsal, but there is little evidence for rehearsal in nonhumans. To further evaluate the possibility that rehearsal contributes to primacy in monkeys, we compared memory for lists of familiar stimuli (which may be easier to rehearse) to memory for unfamiliar stimuli (which are likely difficult to rehearse). Six rhesus monkeys saw lists of five images drawn from either large, medium, or small image sets. After presentation of each list, memory for one item was assessed using a serial probe recognition test. Across four experiments, we found robust primacy and recency with lists drawn from small and medium, but not large, image sets. This finding is consistent with the idea that familiar items are easier to rehearse and that rehearsal contributes to primacy, warranting further study of the possibility of rehearsal in monkeys. However, alternative interpretations are also viable and are discussed. Copyright 2009 Elsevier B.V. All rights reserved.

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

International Nuclear Information System (INIS)

Bartolotta, Tommaso Vincenzo; Taibbi, Adele; Galia, Massimo; Lo Re, Giuseppe; La Grutta, Ludovico; Grassi, Roberto; Midiri, Massimo

2007-01-01

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

Energy Technology Data Exchange (ETDEWEB)

Bartolotta, Tommaso Vincenzo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: tv.bartolotta@unipa.it; Taibbi, Adele [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: taibbi_adele@yahoo.it; Galia, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mgalia@yahoo.com; Lo Re, Giuseppe [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: giuseppe.lore12@tin.it; La Grutta, Ludovico [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: lagrutta@mbox.infcom.it; Grassi, Roberto [Institute of Radiology, Second University of Naples, Piazza Miraglia, 80138 Naples (Italy)], E-mail: roberto.grassi@libero.it; Midiri, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mmidiri@hotmail.com

2007-12-15

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma.