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1
Xu, H. X., G. M. Wang, C. X. Zhang, and X. Wang. "Characterisation of composite right/left-handed transmission line." Electronics Letters 47, no. 18 (2011): 1030. http://dx.doi.org/10.1049/el.2010.3707.
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Carchon, G., and B. Nauwelaers. "Accurate transmission line characterisation on high and low-resistivity substrates." IEE Proceedings - Microwaves, Antennas and Propagation 148, no. 5 (2001): 285. http://dx.doi.org/10.1049/ip-map:20010675.
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Kim, Dongchul, Hyewon Kim, and Yungseon Eo. "A novel transmission line characterisation based on measurement data reconfirmation." International Journal of Electronics 101, no. 4 (April 29, 2013): 479–91. http://dx.doi.org/10.1080/00207217.2013.785032.
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Cassidy, P. "Electromagnetic characterisation of MR RF coils using the transmission-line modelling method." Magnetic Resonance Materials in Biology, Physics, and Medicine 14, no. 1 (March 1, 2002): 20–29. http://dx.doi.org/10.1016/s1352-8661(01)00153-3.
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Cassidy, P. J., S. Grieve, K. Clarke, and D. J. Edwards. "Electromagnetic characterisation of MR RF coils using the transmission-line modelling method." Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine 14, no. 1 (February 2002): 20–29. http://dx.doi.org/10.1007/bf02668183.
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Lee, H. S., D. H. Shin, Y. H. Chun, S. C. Kim, B. O. Lim, T. J. Baek, S. K. Kim, H. C. Park, and J. K. Rhee. "Design and characterisation of micromachined transmission line with dielectric post for millimetre-wave applications." Electronics Letters 39, no. 25 (2003): 1827. http://dx.doi.org/10.1049/el:20031193.
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Kim, D., H. Kim, and Y. Eo. "Experimental characterisations of thin film transmission line losses." Electronics Letters 49, no. 17 (August 2013): 1084–86. http://dx.doi.org/10.1049/el.2013.1444.
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Oluyomi Ajibade, Adedayo, llesanmi Banjo Oluwafemi, and Israel Esan Owolabi. "Characterisation of Signal Amplitude-Frequency for Indoor Power Line Communication Channel in the 1 — 30 MHz Broadband Frequencies." International journal of electrical and computer engineering systems 12, no. 1 (April 21, 2021): 33–41. http://dx.doi.org/10.32985/ijeces.12.1.4.
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The transmission of data signals over power lines is a very promising technique for delivering indoor broadband communication services. However, since power grids were originally designed for high-voltage low-frequency signal transmission, there is a frequency mismatch between the power grid and high-frequency data signals. This mismatch poses a challenge to deploying power lines as a communication channel. Although, studies and researches conducted in several countries have made transmission of data over power lines possible, the behaviour and properties of the power grid cannot be generalised. Hence, the need for in-depth experiment and measurement on the suitability and capability of the Nigerian power grid for data transmission is crucial for proper characterising and modelling of the power line communication (PLC) channel. In this paper, we present experimental measurements and results of the effects of frequency variations on the attenuation experienced by broadband high-speed data signals transmitted over the Nigerian indoor power line network.
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Ng, Sing K., Paul Ainsworth, Andrew Plunkett, Arthur D. Haigh, Andrew A. P. Gibson, Graham Parkinson, Valentina Stojceska, and George Jacobs. "The characterisation of extruded brewer’s spent grain and resistant starch using a microwave transmission line technique." Journal of Food Engineering 83, no. 4 (December 2007): 614–20. http://dx.doi.org/10.1016/j.jfoodeng.2007.04.018.
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Qureshi, Suhail Asghar, Zuhairiah Zainal Abidin, Adel Yahya Isa Ashyap, Huda A. Majid, Muhammad Ramlee Kamarudin, Ma Yue, Mohd Syis Zulkipli, and Jamel Nebhen. "Millimetre-Wave Metamaterial-Based Sensor for Characterisation of Cooking Oils." International Journal of Antennas and Propagation 2021 (March 12, 2021): 1–10. http://dx.doi.org/10.1155/2021/5520268.
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The characterisation of the cooking oils presents a significant challenge due to minor changes in their dielectric behaviour. In this paper, a new metamaterial-based sensor incorporating a split-ring resonator (SRR) with a microstrip transmission line is presented to characterise cooking oils. The design demonstrates metamaterial characteristics of negative permittivity and permeability simultaneously at the resonance frequency. Furthermore, its operation in the range of millimetre-wave frequencies can further enhance its sensitivity, especially for liquid materials. The sensor’s novelty is the operation at millimetre-wave frequencies that offers a high shift in the transmission coefficient while operating at 30 GHz. The sensor’s performance analysis is undertaken by using six MUTs with dielectric constants ranging from 0.126 to 4.47. The presented structure designed on 12 × 8 mm2 Rogers substrate offers a sensitivity of 1.12 GHz per unit change in dielectric constant. The phase's shift demonstrates a lower percentage error than the amplitude and linearly moves towards higher frequencies with the increase in dielectric constant and tangent loss of MUT. The designed sensor can be prominently useful for detecting liquids' chemical characteristics in chemistry and medicine fields.
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Luque, R., N. Casasayas-Barris, H. Parviainen, G. Chen, E. Pallé, J. Livingston, V. J. S. Béjar, et al. "Obliquity measurement and atmospheric characterisation of the WASP-74 planetary system." Astronomy & Astrophysics 642 (October 2020): A50. http://dx.doi.org/10.1051/0004-6361/202038703.
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We present new transit observations of the hot Jupiter WASP-74 b (Teq ~ 1860 K) using the high-resolution spectrograph HARPS-N and the multi-colour simultaneous imager MuSCAT2. We refined the orbital properties of the planet and its host star and measured its obliquity for the first time. The measured sky-projected angle between the stellar spin-axis and the orbital axis of the planet is compatible with an orbit that is well-aligned with the equator of the host star (λ = 0.77 ± 0.99 deg). We are not able to detect any absorption feature of Hα or any other atomic spectral features in the high-resolution transmission spectra of this source owing to low S/N at the line cores. Despite previous claims regarding the presence of strong optical absorbers such as TiO and VO gases in the atmosphere of WASP-74 b, new ground-based photometry combined with a reanalysis of previously reported observations from the literature show a slope in the low-resolution transmission spectrum that is steeper than expected from Rayleigh scattering alone.
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Jaeger, Herman, and Pádraig Cantillon-Murphy. "Distorter Characterisation Using Mutual Inductance in Electromagnetic Tracking." Sensors 18, no. 9 (September 12, 2018): 3059. http://dx.doi.org/10.3390/s18093059.
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Electromagnetic tracking (EMT) is playing an increasingly important role in surgical navigation, medical robotics and virtual reality development as a positional and orientation reference. Though EMT is not restricted by line-of-sight requirements, measurement errors caused by magnetic distortions in the environment remain the technology’s principal shortcoming. The characterisation, reduction and compensation of these errors is a broadly researched topic, with many developed techniques relying on auxiliary tracking hardware including redundant sensor arrays, optical and inertial tracking systems. This paper describes a novel method of detecting static magnetic distortions using only the magnetic field transmitting array. An existing transmitter design is modified to enable simultaneous transmission and reception of the generated magnetic field. A mutual inductance model is developed for this transmitter design in which deviations from control measurements indicate the location, magnitude and material of the field distorter to an approximate degree. While not directly compensating for errors, this work enables users of EMT systems to optimise placement of the magnetic transmitter by characterising a distorter’s effect within the tracking volume without the use of additional hardware. The discrimination capabilities of this method may also allow researchers to apply material-specific compensation techniques to minimise position error in the clinical setting.
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Nottle, M. B., I. M. Vassiliev, S. Vassilieva, L. F. S. Beebe, S. J. Harrison, and S. M. McIlfatrick. "001. ISOLATION AND CHARACTERISATION OF PORCINE ES CELLS." Reproduction, Fertility and Development 21, no. 9 (2009): 1. http://dx.doi.org/10.1071/srb09abs001.
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Embryonic stem (ES) cellshave the capacity for self renewal, can remain undifferentiated in long term culture and can contribute to all the cells in the body including the germ cells. EScells have been isolated in mice and have also been described for humans. However despite considerable effort for more than two decades ES cellswhich can contribute to the germline are yet to be isolated for the pig or any domestic species for that matter. We have developed a new method for isolating porcine ES cells which uses whole embryos cultured in alpha MEM with 10% serum replacement plus additives under 5% O2. Unlike methods employed previously this method results in homogenous outgrowths whose cells resemble ES cells and which express Oct 4 and Nanog and SSEA-1 [1]. These cells can be passaged and cryopreserved repeatedly resulting in the establishment of cell lines at similar efficiencies to that reported previously for 129Sv mice [2]. These cells can form embryoid bodies and can be differentiated to various cell types representative of all three germ layers [3]. Following their injection into blastocysts these cells localise /become incorporated in the inner cell mass and can be used to produce chimaeras when these embryos are transferred to recipient animals [2]. To date we have produced chimaeric pigs from one male ES cell line [2]. These are currently being mated to demonstrate germline transmission. Future studies will examine the applicability of our method to other species commencing with mice and cattle before extending these to humans.
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Wunderlich, Fabian, Mareike Godolt, John Lee Grenfell, Steffen Städt, Alexis M. S. Smith, Stefanie Gebauer, Franz Schreier, Pascal Hedelt, and Heike Rauer. "Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs." Astronomy & Astrophysics 624 (April 2019): A49. http://dx.doi.org/10.1051/0004-6361/201834504.
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Context. The characterisation of the atmosphere of exoplanets is one of the main goals of exoplanet science in the coming decades. Aims. We investigate the detectability of atmospheric spectral features of Earth-like planets in the habitable zone (HZ) around M dwarfs with the future James Webb Space Telescope (JWST). Methods. We used a coupled 1D climate-chemistry-model to simulate the influence of a range of observed and modelled M-dwarf spectra on Earth-like planets. The simulated atmospheres served as input for the calculation of the transmission spectra of the hypothetical planets, using a line-by-line spectral radiative transfer model. To investigate the spectroscopic detectability of absorption bands with JWST we further developed a signal-to-noise ratio (S/N) model and applied it to our transmission spectra. Results. High abundances of methane (CH4) and water (H2O) in the atmosphere of Earth-like planets around mid to late M dwarfs increase the detectability of the corresponding spectral features compared to early M-dwarf planets. Increased temperatures in the middle atmosphere of mid- to late-type M-dwarf planets expand the atmosphere and further increase the detectability of absorption bands. To detect CH4, H2O, and carbon dioxide (CO2) in the atmosphere of an Earth-like planet around a mid to late M dwarf observing only one transit with JWST could be enough up to a distance of 4 pc and less than ten transits up to a distance of 10 pc. As a consequence of saturation limits of JWST and less pronounced absorption bands, the detection of spectral features of hypothetical Earth-like planets around most early M dwarfs would require more than ten transits. We identify 276 existing M dwarfs (including GJ 1132, TRAPPIST-1, GJ 1214, and LHS 1140) around which atmospheric absorption features of hypothetical Earth-like planets could be detected by co-adding just a few transits. Conclusions. The TESS satellite will likely find new transiting terrestrial planets within 15 pc from the Earth. We show that using transmission spectroscopy, JWST could provide enough precision to be able to partly characterise the atmosphere of TESS findings with an Earth-like composition around mid to late M dwarfs.
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Mittal, Gaurav, and Nagendra Prasad Pathak. "Design, Analysis and Characterisation of Spoof Surface Plasmon Polaritons based Wideband Bandpass Filter at Microwave Frequency." Defence Science Journal 68, no. 3 (April 16, 2018): 300. http://dx.doi.org/10.14429/dsj.68.11981.
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<p>This paper presents the wideband bandpass filter (BPF) in the microwave frequency domain. The realisation approach is based on spoof surface plasmon polaritons (SSPPs) phenomenon using plasmonic metamaterial. A novel unit cell is designed for filter design using an LC resonator concept. Then SSPPs BPF is realised using an optimised mode converter and five unit cells. This paper includes a brief design detail of the proposed novel unit cell. The passband of BPF is achieved at approximately 1.20 - 5.80 GHz, 3dB bandwidth is tentatively 4.60 GHz and the insertion loss is less than 2 dB approximately over the passband. The overall dimension of fabricated filter is (90 x 45) mm. A basic schematic of transmission line representation is also proposed to evaluate the BPF structure.</p>
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Ovaska, Sami-Seppo, Ville Leminen, Panu Tanninen, Matti Manninen, Katriina Mielonen, Sami Matthews, Henry Lindell, and Kaj Backfolk. "Characterisation of Pulsed-Fibre-Laser-Perforated Polymeric Food Package Films." Polymers and Polymer Composites 26, no. 4 (May 2018): 273–82. http://dx.doi.org/10.1177/096739111802600401.
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A packaging material requires a proper interaction with regard to water vapour transmission between the product and the outside environment. For many fresh food products such as bakery goods, fruits, and vegetables, microperforation is utilised to extend the shelf life of the foodstuff and to provide better food quality. The microperforation potential of five commercial polymeric films has been evaluated using a pulsed fibre laser technique, and significant differences were found between the films in the penetration of the laser beam and in the diameter of the perforation. Breathable polymeric packaging films were prepared with an average laser power of 20 W and a pulse duration of 200 ns. The numbers of holes (80 μm in diameter) in the films were approx. 2000 holes/m2 and 4000 holes/m2. As expected, the number of perforations affected the water vapour transmission (WVT): the WVT was 11 g/m2/d for unperforated film, and 60 g/m2/d for the film with 4000 holes/m2, indicating that the fibre laser can be used successfully for microperforating this type of polymeric films. However, microscopic and microtomographic analyses revealed major differences in hole formation behaviour and in the wall structures of the microperforations.
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Bálint, Ádám, István Kiss, Krisztián Bányai, Imre Biksi, Katalin Szentpáli-Gavallér, Tibor Magyar, István Jankovics, et al. "Emergence and characterisation of pandemic H1N1 influenza viruses in Hungarian swine herds." Acta Veterinaria Hungarica 61, no. 1 (March 1, 2013): 125–34. http://dx.doi.org/10.1556/avet.2012.059.
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In 2010, two novel porcine H1N1 influenza viruses were isolated from pigs with influenza-like illness in Hungarian swine herds. Sequence and phylogenetic analysis of these strains revealed that they shared molecular features with the pandemic H1N1 influenza virus strains, which emerged globally during 2009. The PB2, HA and NA genes contained unique amino acid changes compared to the available new H1N1 influenza virus sequences of pig origin. Furthermore, the investigated strains could be separated with respect to parallel amino acid substitutions affecting the polymerase genes (PB2, PB1 and PA) and the nucleoprotein (NP) gene, supporting the proposed complementarities between these proteins, all required for the viral fitness. Molecular characterisation of two Hungarian human pandemic H1N1 isolates was also performed, so that we could compare contemporaneous strains of different host species origins. Shared molecular motifs in various genes of animal and human influenza strains suggested that the Hungarian porcine strains could have originated from humans through direct interspecies transmission. This study is among the few that support the natural human-to-pig transmission of the pandemic H1N1 influenza virus.
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Ghoshal, Dibyendu. "A Study on the Impedance Characterisation of Radial Transmission Line to Explain the Properties of Millimeter Wave 35-GHz Resonant-cap Impatt Oscillators." IETE Journal of Research 44, no. 3 (May 1998): 95–98. http://dx.doi.org/10.1080/03772063.1998.11416034.
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Escobedo-Cousin, Enrique, Konstantin Vassilevski, Irina P. Nikitina, Nicolas G. Wright, Anthony G. O'Neill, Alton B. Horsfall, and Jonathan P. Goss. "Local Solid Phase Epitaxy of Few-Layer Graphene on Silicon Carbide." Materials Science Forum 717-720 (May 2012): 629–32. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.629.
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Patterned Few Layers Graphene (FLG) films were grown by local solid phase epitaxy from nickel silicide supersaturated with carbon. The process was realised by annealing of thin Ni films deposited on the carbon-terminated surface of 6H-SiC semi-insulating wafer followed by wet processing to remove the resulting nickel silicide. Raman spectroscopy was used to investigate both the formation and subsequent removal of nickel silicide during processing. Characterisation of the resulting FLG films was carried out by Raman spectroscopy and Atomic Force Microscopy (AFM). The thickness of the final FLG film estimated from the Raman spectra varied from 1 to 3 monolayers for initial Ni layers varying from 3 to 20 nm thick. AFM observations revealed process-induced surface roughening in FLG films, however, electrical conductivity measurements by Transmission Line Model (TLM) structures confirmed that roughness does not compromise the film sheet resistance.
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Oestrup, Esben, Jakob Gjoerret, Kirsten Schauser, Mette Schmidt, Vanessa Hall, and Poul Hyttel. "Characterisation of bovine epiblast-derived outgrowth colonies." Reproduction, Fertility and Development 22, no. 4 (2010): 625. http://dx.doi.org/10.1071/rd08300.
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The aim of the present study was to characterise bovine epiblast-derived outgrowth colonies (OCs) with respect to the embryonic origin of their cellular components. Epiblasts were isolated mechanically from bovine Day 12 embryos. Epiblasts were cultured on feeder layers of SNL cells (neomycin-resistant leukaemia inhibitory factor (LIF)-producing STO cells) in Dulbecco’s modified Eagle’s medium (DMEM)/F12 medium supplemented with 15% fetal calf serum, 5% KnockOut Serum Replacement, LIF, basic fibroblast growth factor, non-essential amino acids (NEAA) and nucleosides. Samples were fixed on Days 4, 6 and 8 of culture and processed for immunocytochemistry and transmission electron microscopy. Epiblasts formed OCs consisting of a central core of epiblast-like cells with a basal plate of flattened cells extending outwards from the core. The cells of the core showed nuclear octamer-binding transcription factor 4 (OCT4) staining, indicating an epiblast origin, and some also stained positive for cytoplasmic vimentin. Adjacent cells were linked by tight junctions towards the surface of the colony and rested on a basal lamina. The cells of the basal plate predominantly stained for α1-fetoprotein (AFP), indicative of a possible hypoblast origin. Only a few cells scattered within the basal plate exhibited cytokeratin 8 staining, indicating a trophectoderm nature. The intensity of OCT4 and vimentin staining within the core had decreased by Day 8 of culture. In conclusion, OCs derived from bovine Day 12 epiblasts display a central core of OCT4-stained cells of a potential epiblast origin surrounded by a basal plate of mainly AFP-stained cells of a potential hypoblast nature.
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Bürger, Julius, Vinay S. Kunnathully, Daniel Kool, Jörg K. N. Lindner, and Katharina Brassat. "Characterisation of the PS-PMMA Interfaces in Microphase Separated Block Copolymer Thin Films by Analytical (S)TEM." Nanomaterials 10, no. 1 (January 13, 2020): 141. http://dx.doi.org/10.3390/nano10010141.
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Block copolymer (BCP) self-assembly is a promising tool for next generation lithography as microphase separated polymer domains in thin films can act as templates for surface nanopatterning with sub-20 nm features. The replicated patterns can, however, only be as precise as their templates. Thus, the investigation of the morphology of polymer domains is of great importance. Commonly used analytical techniques (neutron scattering, scanning force microscopy) either lack spatial information or nanoscale resolution. Using advanced analytical (scanning) transmission electron microscopy ((S)TEM), we provide real space information on polymer domain morphology and interfaces between polystyrene (PS) and polymethylmethacrylate (PMMA) in cylinder- and lamellae-forming BCPs at highest resolution. This allows us to correlate the internal structure of polymer domains with line edge roughnesses, interface widths and domain sizes. STEM is employed for high-resolution imaging, electron energy loss spectroscopy and energy filtered TEM (EFTEM) spectroscopic imaging for material identification and EFTEM thickness mapping for visualisation of material densities at defects. The volume fraction of non-phase separated polymer species can be analysed by EFTEM. These methods give new insights into the morphology of polymer domains the exact knowledge of which will allow to improve pattern quality for nanolithography.
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Brogi, M., P. Giacobbe, G. Guilluy, R. J. de Kok, A. Sozzetti, L. Mancini, and A. S. Bonomo. "Exoplanet atmospheres with GIANO." Astronomy & Astrophysics 615 (July 2018): A16. http://dx.doi.org/10.1051/0004-6361/201732189.
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Context. High-resolution spectroscopy (R ≥ 20 000) at near-infrared wavelengths can be used to investigate the composition, structure, and circulation patterns of exoplanet atmospheres. However, up to now it has been the exclusive dominion of the biggest telescope facilities on the ground, due to the large amount of photons necessary to measure a signal in high-dispersion spectra. Aims. Here we show that spectrographs with a novel design – in particular a large spectral range – can open exoplanet characterisation to smaller telescope facilities too. We aim to demonstrate the concept on a series of spectra of the exoplanet HD 189 733 b taken at the Telescopio Nazionale Galileo with the near-infrared spectrograph GIANO during two transits of the planet. Methods. In contrast to absorption in the Earth’s atmosphere (telluric absorption), the planet transmission spectrum shifts in radial velocity during transit due to the changing orbital motion of the planet. This allows us to remove the telluric spectrum while preserving the signal of the exoplanet. The latter is then extracted by cross-correlating the residual spectra with template models of the planet atmosphere computed through line-by-line radiative transfer calculations, and containing molecular absorption lines from water and methane. Results. By combining the signal of many thousands of planet molecular lines, we confirm the presence of water vapour in the atmosphere of HD 189 733 b at the 5.5σ level. This signal was measured only in the first of the two observing nights. By injecting and retrieving artificial signals, we show that the non-detection on the second night is likely due to an inferior quality of the data. The measured strength of the planet transmission spectrum is fully consistent with past CRIRES observations at the VLT, excluding a strong variability in the depth of molecular absorption lines.
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Johnson, Suzanne M., Antonia Banyard, Christopher Smith, Aleksandr Mironov, and Martin G. McCabe. "Large Extracellular Vesicles Can be Characterised by Multiplex Labelling Using Imaging Flow Cytometry." International Journal of Molecular Sciences 21, no. 22 (November 18, 2020): 8723. http://dx.doi.org/10.3390/ijms21228723.
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Extracellular vesicles (EVs) are heterogeneous in size (30 nm–10 µm), content (lipid, RNA, DNA, protein), and potential function(s). Many isolation techniques routinely discard the large EVs at the early stages of small EV or exosome isolation protocols. We describe here a standardised method to isolate large EVs from medulloblastoma cells and examine EV marker expression and diameter using imaging flow cytometry. Our approach permits the characterisation of each large EVs as an individual event, decorated with multiple fluorescently conjugated markers with the added advantage of visualising each event to ensure robust gating strategies are applied. Methods: We describe step-wise isolation and characterisation of a subset of large EVs from the medulloblastoma cell line UW228-2 assessed by fluorescent light microscopy, transmission electron microscopy (TEM) and tunable resistance pulse sensing (TRPS). Viability of parent cells was assessed by Annexin V exposure by flow cytometry. Imaging flow cytometry (Imagestream Mark II) identified EVs by direct fluorescent membrane labelling with Cell Mask Orange (CMO) in conjunction with EV markers. A stringent gating algorithm based on side scatter and fluorescence intensity was applied and expression of EV markers CD63, CD9 and LAMP 1 assessed. Results: UW228-2 cells prolifically release EVs of up to 6 µm. We show that the Imagestream Mark II imaging flow cytometer allows robust and reproducible analysis of large EVs, including assessment of diameter. We also demonstrate a correlation between increasing EV size and co-expression of markers screened. Conclusions: We have developed a labelling and stringent gating strategy which is able to explore EV marker expression (CD63, CD9, and LAMP1) on individual EVs within a widely heterogeneous population. Taken together, data presented here strongly support the value of exploring large EVs in clinical samples for potential biomarkers, useful in diagnostic screening and disease monitoring.
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Sharp, Colin P., William F. Gregory, Louise Hattingh, Amna Malik, Emily Adland, Samantha Daniels, Anriette van Zyl, et al. "PARV4 prevalence, phylogeny, immunology and coinfection with HIV, HBV and HCV in a multicentre African cohort." Wellcome Open Research 2 (April 7, 2017): 26. http://dx.doi.org/10.12688/wellcomeopenres.11135.1.
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Background: The seroprevalence of human parvovirus-4 (PARV4) varies considerably by region. In sub-Saharan Africa, seroprevalence is high in the general population, but little is known about the transmission routes or the prevalence of coinfection with blood-borne viruses, HBV, HCV and HIV. Methods: To further explore the characteristics of PARV4 in this setting, with a particular focus on the prevalence and significance of coinfection, we screened a cohort of 695 individuals recruited from Durban and Kimberley (South Africa) and Gaborone (Botswana) for PARV4 IgG and DNA, as well as documenting HIV, HBV and HCV status. Results: Within these cohorts, 69% of subjects were HIV-positive. We identified no cases of HCV by PCR, but 7.4% were positive for HBsAg. PARV4 IgG was positive in 42%; seroprevalence was higher in adults (69%) compared to children (21%) (p<0.0001) and in HIV-positive (52%) compared to HIV-negative individuals (24%) (p<0.0001), but there was no association with HBsAg status. We developed an on-line tool to allow visualization of coinfection data (https://purl.oclc.org/coinfection-viz). We identified five subjects who were PCR-positive for PARV4 genotype-3. Ex vivo CD8+ T cell responses spanned the entire PARV4 proteome and we propose a novel HLA-B*57:03-restricted epitope within the NS protein. Conclusions: This characterisation of PARV4 infection provides enhanced insights into the epidemiology of infection and co-infection in African cohorts, and provides the foundations for planning further focused studies to elucidate transmission pathways, immune responses, and the clinical significance of this organism.
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Priyadarsini, Kavirayani Indira, Beena G. Singh, Prasad P. Phadnis, Kanhu Charan Barick, and Puthusserickal Abdulrahiman Hassan. "Nanoparticle Conjugates of Selenium Compounds: Preparation, Characterisation and Electron Transfer." Chemistry Proceedings 2, no. 1 (November 9, 2020): 24. http://dx.doi.org/10.3390/eccs2020-07545.
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One of the important features influencing the biological applications of organoselenium compounds is their redox state, which in turn is affected by their interactions with nearby heteroatoms. To modulate the biological action of selenium in such compounds, researchers have designed new structural motifs and also developed new formulations using inorganic nanoparticles. Metal nanoparticles such as gold nanoparticles (GNPs) and magnetic nanoparticles (MNPs) like iron oxide (Fe3O4) have been extensively studied for conjugation with many heteroatoms (sulphur, nitrogen and oxygen) containing ligands. Selenium, being more polarisable than sulphur, can induce significant surface passivation, thereby providing easy modulations with physico-chemical properties. Considering this, we investigated the physico-chemical properties of a few selenium compounds conjugated to GNPs and MNPs. The GNP conjugates were characterised by spectroscopic and microscopic tools, such as optical absorption, Raman spectroscopy, dynamic light scattering (DLS), the zeta potential and transmission electron microscopy (TEM). The results confirmed that the selenium atom was covalently conjugated to GNPs and this conjugation not only increased their electron transfer ability, but also their antioxidant ability. In another study, asymmetric phenyl selenides were conjugated with MNPs and characterised byX-ray diffraction (XRD), TEM, DLS and zeta potential. The radical scavenging ability of the selenium compounds improved upon conjugation with the MNPs. Therefore, the above studies confirmed that the redox activities of selenium compounds can be modulated upon conjugation with inorganic nanoparticles, such as GNPs and MNPs, which in turn provides new avenues for delivering organoselenium compounds.
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Fu, Hanwei, and Pedro E. J. Rivera-Díaz-del-Castillo. "Evolution of White Etching Bands in 100Cr6 Bearing Steel under Rolling Contact-Fatigue." Metals 9, no. 5 (April 27, 2019): 491. http://dx.doi.org/10.3390/met9050491.
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The formation of white etching bands (WEBs) occurs at the subsurface of rolling contact-fatigued bearing inner rings, exhibiting microstructural decay detrimental to bearing life. Despite the fact that WEBs have been observed in bearing steels for nearly 70 years, the understanding of WEB formation is still limited and mostly qualitative. Therefore, a systematic investigation is carried out in this research to reveal the evolution of WEBs with respect to the number of contact cycles. WEBs formed at different stages are reproduced by full-scale bearing RCF tests with predetermined numbers of cycles. Multi-scale characterisation techniques such as optical microscopy, micro-indentation, scanning and transmission electron microscopy and atomic force microscopy are conducted on the microstructural alterations to study the development and microstructure of WEBs. WEBs are found in the absence of dark etching regions which is attributed to the heat treatment. With an increasing number of cycles, WEBs grow in number density and in all three dimensions, and their formation is found to be controlled by the maximum shear stress component. Ferrite bands within WEBs that contain dislocation cells manifest accumulated plastic strain in the material. Based on the characterisation results, the evolution of plastic strain under RCF is quantified.
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Maringa, Wairimu M., Peter N. Mwangi, Julia Simwaka, Evans M. Mpabalwani, Jason M. Mwenda, Ina Peenze, Mathew D. Esona, M. Jeffrey Mphahlele, Mapaseka L. Seheri, and Martin M. Nyaga. "Molecular Characterisation of a Rare Reassortant Porcine-Like G5P[6] Rotavirus Strain Detected in an Unvaccinated Child in Kasama, Zambia." Pathogens 9, no. 8 (August 17, 2020): 663. http://dx.doi.org/10.3390/pathogens9080663.
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A human-porcine reassortant strain, RVA/Human-wt/ZMB/UFS-NGS-MRC-DPRU4723/2014/G5P[6], was identified in a sample collected in 2014 from an unvaccinated 12 month old male hospitalised for gastroenteritis in Zambia. We sequenced and characterised the complete genome of this strain which presented the constellation: G5-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. The genotype A8 is often observed in porcine strains. Phylogenetic analyses showed that VP6, VP7, NSP2, NSP4, and NSP5 genes were closely related to cognate gene sequences of porcine strains (e.g., RVA/Pig-wt/CHN/DZ-2/2013/G5P[X] for VP7) from the NCBI database, while VP1, VP3, VP4, and NSP3 were closely related to porcine-like human strains (e.g., RVA/Human-wt/CHN/E931/2008/G4P[6] for VP1, and VP3). On the other hand, the origin of the VP2 was not clear from our analyses, as it was not only close to both porcine (e.g., RVA/Pig-tc/CHN/SWU-1C/2018/G9P[13]) and porcine-like human strains (e.g., RVA/Human-wt/LKA/R1207/2009/G4P[6]) but also to three human strains (e.g., RVA/Human-wt/USA/1476/1974/G1P[8]). The VP7 gene was located in lineage II that comprised only porcine strains, which suggests the occurrence of independent porcine-to-human reassortment events. The study strain may have collectively been derived through interspecies transmission, or through reassortment event(s) involving strains of porcine and porcine-like human origin. The results of this study underline the importance of whole-genome characterisation of rotavirus strains and provide insights into interspecies transmissions from porcine to humans.
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Naser, Abdelrahman Moukhtar, Hamada Abd El - Wahab, Mohamed Abd El Fattah Moustafa El Nady, Abdelzaher E.A. Mostafa, Long Lin, and Ahmed Galal Sakr. "Preparation and characterisation of modified reclaimed asphalt using nanoemulsion acrylate terpolymer." Pigment & Resin Technology 48, no. 5 (September 2, 2019): 363–74. http://dx.doi.org/10.1108/prt-08-2018-0080.
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Purpose This paper aims to investigate the best methods of utilisation of reclaimed asphalt pavements (RAP) in Egypt, to determine the effect of using 100% RAP instead of using virgin aggregates and asphalt; investigate the effect of thermoplastic elastomer polymer as asphalt modifier; and also improve the mechanical and physical characteristics and consequently improving the quality of asphalt paving, increasing service life of asphalt-paving and reducing costs. Design/methodology/approach Nano acrylate terpolymers were prepared with different % (Wt.) of and were characterised by Fourier transforms infrared (FTIR), for molecular weight (Mw), by thermo gravimetric analysis (TGA) and by transmission electron microscopy (TEM). A 4% (Wt.) of the prepared nanoemulsion terpolymer was mixed with virgin asphalt as a polymer modifier, to improve and reuse of the RAP. The modified binder was tested. The tests conducted include penetration, kinematic viscosity, softening point and specific gravity. Application of Marshall mix design types; hot mix asphalt (HMA), warm mix asphalt (WMA) and cold in place recycled (CIR). Four different mix designs used; control mix contained virgin asphalt by HMA, and the other three mix designs were polymermodified asphalt sample by HMA, WMA and CIR. Findings The research results showed that using 4 Wt.% of the prepared nanoemulsion terpolymer to produce hot mix asphalt (HMA) and warm mix asphalt (WMA) achieved higher stability compared to the control mix and cold in place recycled (CIR). Research limitations/implications This paper discusses the preparation and the characterisation of nanoemulsion and its application in RAPs to enhance and improve the RAP quality. Practical implications Nano-acrylate terpolymer can be used as a new polymer to modify asphalt to achieve the required specifications for RAP. Originality/value According to the most recent surveys, Europe produced 265 tonnes of asphalt for road applications in 2014, while the amount of available RAP was more than 50 tonnes. The use of RAP in new blended mixes reduces the need of neat asphalt, making RAP recycling economically attractive.
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Plamboeck, Astrid, Simon Veedfald, Carolyn F. Deacon, Bolette Hartmann, André Wettergren, Lars B. Svendsen, Søren Meisner, et al. "Characterisation of oral and i.v. glucose handling in truncally vagotomised subjects with pyloroplasty." European Journal of Endocrinology 169, no. 2 (August 2013): 187–201. http://dx.doi.org/10.1530/eje-13-0264.
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ObjectiveGlucagon-like peptide 1 (GLP1) is rapidly inactivated by dipeptidyl peptidase 4 (DPP4), but may interact with vagal neurons at its site of secretion. We investigated the role of vagal innervation for handling of oral and i.v. glucose.Design and methodsTruncally vagotomised subjects (n=16) and matched controls (n=10) underwent 50 g-oral glucose tolerance test (OGTT)±vildagliptin, a DPP4 inhibitor (DPP4i) and isoglycaemic i.v. glucose infusion (IIGI), copying the OGTT without DPP4i.ResultsIsoglycaemia was obtained with 25±2 g glucose in vagotomised subjects and 18±2 g in controls (P<0.03); thus, gastrointestinal-mediated glucose disposal (GIGD) – a measure of glucose handling (100%×(glucoseOGTT−glucoseIIGI/glucoseOGTT)) – was reduced in the vagotomised compared with the control group. Peak intact GLP1 concentrations were higher in the vagotomised group. Gastric emptying was faster in vagotomised subjects after OGTT and was unaffected by DPP4i. The early glucose-dependent insulinotropic polypeptide response was higher in vagotomised subjects. Despite this, the incretin effect was equal in both groups. DPP4i enhanced insulin secretion in controls, but had no effect in the vagotomised subjects. Controls suppressed glucagon concentrations similarly, irrespective of the route of glucose administration, whereas vagotomised subjects showed suppression only during IIGI and exhibited hyperglucagonaemia following OGTT. DPP4i further suppressed glucagon secretion in controls and tended to normalise glucagon responses in vagotomised subjects.ConclusionsGIGD is diminished, but the incretin effect is unaffected in vagotomised subjects despite higher GLP1 levels. This, together with the small effect of DPP4i, is compatible with the notion that part of the physiological effects of GLP1 involves vagal transmission.
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Frint, Philipp, Matthias Hockauf, T. Halle, G. Strehl, Thomas Lampke, and Martin F. X. Wagner. "Microstructural Features and Mechanical Properties after Industrial Scale ECAP of an Al 6060 Alloy." Materials Science Forum 667-669 (December 2010): 1153–58. http://dx.doi.org/10.4028/www.scientific.net/msf.667-669.1153.
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Future applications of ultrafine-grained, high performance materials produced by equal-channel angular pressing (ECAP) will most likely require processing on an industrial scale. There is a need for detailed microstructural and mechanical characterisation of large-scale, ECAP-processed billets. In the present study, we examine the microstructure and mechanical properties as a function of location and orientation within large (50 x 50 x 300 mm³) billets of an Al 6060 alloy produced by ECAP (90° channel angle) with different magnitudes of backpressure. The internal deformation is analysed using a grid-line method on split billets. Hardness is recorded in longitudinal and cross-sectional planes. In order to further characterise the local, post-ECAP mechanical properties, tensile tests in different layers are performed. Moreover, low voltage scanning transmission electron microscopy observations highlight relevant microstructural features. We find that the homogeneity and anisotropy of mechanical properties within the billets depend significantly on the geometry of the shear zone. We demonstrate that deformation gradients can be reduced considerably by increasing the backpressure: The opening-angle of the fan-shaped shear zone is reduced from ψ ≈ 20 ° to ψ ≈ 7 ° when the backpressure is increased from 0 to 150 MPa. Backpressures of 150 MPa result in excellent homogeneity, with a relative variation of tensile mechanical properties of less than 7 %. Our investigation demonstrates that ECAP is suitable for processing homogenous, high performance materials on a large scale, paving the way for advanced industrial applications.
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Lakner, H. "Subnanometer electron probes and their capabilities for internal interface characterization." Microscopy and Microanalysis 3, S2 (August 1997): 643–44. http://dx.doi.org/10.1017/s1431927600010102.
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Internal interfaces in materials like e.g. semiconductor heterostructures get more and more interest not only under aspects of basic research but as well under aspects of new electronic and optoelectronic devices. The interface properties often govern the device performance. Thus, the evaluation of individual heterointerfaces with respect to chemical composition and crystal structure requires characterisation techniques which offer the necessary high spatial resolution. The fine focused electron probe (< 0.3 nm at 100 keV) in a field-emission STEM (Scanning Transmission Electron Microscope) allows the application of special imaging and analytical techniques to cross-sectional specimens of semiconductor heterostructures. Qualitative information on the chemical composition is provided by atomic number (Z) contrast imaging with atomic resolution. The same fine probe can be used to analyse subnanometer areas by both spectroscopic and diffraction techniques. Quantitative compositional information is provided by electron energy-loss spectroscopy (EELS) which allows the detection of concentrations of specific elements.
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Kleist, G., and U. Schmitt. "Characterisation of a Soft Rot-Like Decay Pattern Caused by Coniophora puteana (Schum.) Karst. in Sapelli Wood (Entandrophragma cylindricum Sprague)." Holzforschung 55, no. 6 (November 6, 2001): 573–78. http://dx.doi.org/10.1515/hf.2001.093.
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Summary The decay patterns of brown and soft rot fungi in Sapelli wood (Entandrophragma cylindricum Sprague), with respect to natural durability, were examined by light and transmission electron microscopy as well as UV spectroscopy. Analyses revealed that the typical brown rot fungus Coniophora puteana can cause a soft rot-like decay in the sapwood of Sapelli at high moisture contents of approx. 100%. In accordance with the decay pattern of the typical soft rot fungus Chaetomium globosum, the hyphae of C. puteana penetrated the S2 wall of fibres and formed characteristic rhomboidal cavities orientated parallel to the microfibrillar angle. However, these cavities were larger in diameter (3.9 μm ± 0.9) than those formed by C. globosum (2.1 μm ± 0.5) and with a distinct interspace between the hyphae and surrounding walls. Hyphae of C. globosum were directly attached to the undecayed secondary wall. No lignin degradation for both fungi in close vicinity to the cavities was observed, as evidenced by UV spectroscopy. The inclusion of microscopy for definitive decay type identification is recommended.
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Makhsin, Siti Rabizah, Muhammad Izham Hakimi Mohd Zali, Rozina Abdul Rani, Nor Hayati Saad, and Muhammad Azmi Ayub. "Modifies Hummer’s Method of Graphene Oxide Nanostructures for Fibre Optic Sensors Application." Scientific Research Journal 18, no. 1 (February 28, 2021): 15. http://dx.doi.org/10.24191/srj.v18i1.11386.
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For optical fibre sensors applications, nanomaterials have been widely used to enhance sensor performance. Here, the fibre optic uses the transmission of light by total internal reflection along with the fibre and depending on the diameter of the fibre and the wavelength of the light used. Among others, graphene oxides nanostructures (GO) would offer exceptional advantages on the sensing mechanism due to 2D properties of the monocellular layer originally from graphite. The main objectives of this research are to successfully synthesis of GO using a chemical reduction method known as modifies Hummer’s method and later, deposited the GO onto the modified fibre optic layer to create a sensing platform. Prior than that, the standard plastic of fibre optic (POF) was modified by removing the cladding layer (1 cm) using a mechanical etching technique, thus the sensing platform can be created. The morphology and optical properties of the system were characterised using scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) spectroscopy. Result of the preparation and characterisation of GO-optical fibre coatings was presented, considering its potential use for sensing applications. The stable GO was prepared by 3 hours of stirring time during the synthesis and longer dipping time was preferred to fully coat the core of the exposed POF. Aiming to explore this scheme for sensing applications, GO-coated tilted fibre will be later measuring via refractive index variations. An improvement on the sensitivity should be obtained and thus become a promising sensing platform for the development of a new line of sensors.
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Tinetti, Giovanna, James Y.-K. Cho, Caitlin A. Griffith, Olivier Grasset, Lee Grenfell, Tristan Guillot, Tommi T. Koskinen, et al. "The science of EChO." Proceedings of the International Astronomical Union 6, S276 (October 2010): 359–70. http://dx.doi.org/10.1017/s1743921311020448.
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AbstractThe science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are?In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life.The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole.EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.
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Damunupola, Jilushi W., Kamani Ratnayake, Daryl C. Joyce, and Donald E. Irving. "Characterisation of xylem conduits and their possible role in limiting the vase life of cut Acacia holosericea (Mimosaceae) foliage stems." Functional Plant Biology 38, no. 7 (2011): 614. http://dx.doi.org/10.1071/fp11068.
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Early desiccation limits the vase life of Acacia cut flowers and foliage and may be attributable to poor hydraulic conductivity (Kh) of the cut stems. Acacia holosericea A.Cunn. ex G.Don has been adopted as the test species to investigate the postharvest water relations of the genus Acacia. To understand potential constraints on Kh, xylem conduits in cut A. holosericea stems were anatomically characterised by light and scanning and transmission electron microscopy. Vessels with simple perforation plates and tracheids were the principal water conducting cells. Bordered vestured intervessel pits were present in xylem vessel elements. The majority of conduits (89%) were short at 1–5 cm long. Only 2% were 15–16 cm in length. Mean xylem conduit diameter was 77 ± 0.9 µm and the diameter profile showed a normal distribution, with 29% of diameters in the range of 70–80 µm. Simple perforation plates can offer relatively low resistance to water flow. On the other hand, bordered vestured pits and short xylem conduits can confer comparatively high resistance to water flow. Overall, the presence of bordered vestured pits, together with a high proportion of short xylem conduits and high stomatal densities (232 ± 2 mm–2) on unifacial phyllodes, could contribute to early dehydration of A. holosericea cut foliage stems standing in vase water. Further research will relate these anatomical features with changes in Kh and transpiration of cut foliage stems.
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Mohr, PG, MStJ Crane, J. Hoad, LM Williams, D. Cummins, MJ Neave, B. Shiell, et al. "Pilchard orthomyxovirus (POMV). I. Characterisation of an emerging virus isolated from pilchards Sardinops sagax and Atlantic salmon Salmo salar." Diseases of Aquatic Organisms 139 (April 30, 2020): 35–50. http://dx.doi.org/10.3354/dao03470.
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An orthomyxo-like virus was first isolated in 1998 as an incidental discovery from pilchards Sardinops sagax collected from waters off the South Australian coast. In the following 2 decades, orthomyxo-like viruses have been isolated from healthy pilchards in South Australia and Tasmania. In 2006, an orthomyxo-like virus was also isolated from farmed Atlantic salmon Salmo salar in Tasmania during routine surveillance and, again, from 2012 onwards from diseased Atlantic salmon. Using transmission electron microscopy, these viruses were identified as belonging to the family Orthomyxoviridae. To further characterise the viruses, the genomes of 11 viral isolates were sequenced. The open reading frames (ORFs) that encode 10 putative proteins from 8 viral genome segments were assembled from Illumina MiSeq next generation sequencing (NGS) data. The complete genome of a 2014 isolate was also assembled from NGS, RNA-sequencing (RNA-seq) data, that included conserved motifs that shared commonalities with infectious salmon anaemia virus, rainbow trout orthomyxovirus and Influenzavirus A. The presence of 8 viral proteins translated from genome segments was confirmed by mass spectrometric analysis including 2 novel proteins with no known orthologs. Sequence analysis of the ORFs, non-coding regions and proteins indicated that the viruses had minimal diversity and hence were named pilchard orthomyxovirus (POMV), based on the fish host species of its first isolation. The low homology of POMV proteins with previously characterised orthomyxoviruses suggests that POMV is the first virus to be characterised from a new genus within the Orthomyxoviridae. To facilitate more rapid detection and subsequent diagnostic confirmation of POMV infections, TaqMan and conventional nested PCRs were designed.
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Shelly and Minakshi Sharma. "Nitrate Reductase Nanoparticles: Synthesis and Characterization." International Journal of Research in Pharmaceutical Sciences 11, no. 3 (August 7, 2020): 4583–89. http://dx.doi.org/10.26452/ijrps.v11i3.2740.
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Nanoparticles of enzyme Nitrate reductase (NaR) a soluble homodimer enzyme of ∼100 kDa polypeptide with cofactors – FAD, heme-molybdopterin (Mo-MPT) and electron donor NAD(P)H, catalyses the reduction of nitrate to nitrite has been synthesised. Nanoparticles of Nitrate reductase enzyme have been prepared by chemical desolvation method including glutaraldehyde cross-linking to form the nanoaggregate. Characterisation of NaR nanoparticles has been made by Transmission Electron Microscopy (TEM), UV-Visible Spectroscopy and by electrochemical Impedance Spectroscopic Study (EIS). TEM study revealed the size of globular aggregated was in the range of 20–30 nm. UV Visible spectroscopic studies depicted that the absorption of NaR NPS is much higher at 560 nm than that of the free enzyme, which showed maximum absorption at 540 nm. NaR NPs aggregates formed were more active, highly stable, have a higher shelf life and can be reused repeatedly. Enzyme nanoparticles with 10-100 nm dimensions and exhibit unique physical, chemical and catalytic properties due to increased surface area. Nitrate reductase nanoparticles can be used as a biochemical tool to increase protein production and grain yield by promoting amino acids production in plants. The synthesised NaR NPs are used in the fabrication of enzyme-based nanosensor in the detection of nitrates in drinking water and serum samples.
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Bower, Dan J., Daniel Kitzmann, Aaron S. Wolf, Patrick Sanan, Caroline Dorn, and Apurva V. Oza. "Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations." Astronomy & Astrophysics 631 (November 2019): A103. http://dx.doi.org/10.1051/0004-6361/201935710.
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Context. A terrestrial planet is molten during formation and may remain molten due to intense insolation or tidal forces. Observations favour the detection and characterisation of hot planets, potentially with large outgassed atmospheres. Aims. We aim to determine the radius of hot Earth-like planets with large outgassing atmospheres. Our goal is to explore the differences between molten and solid silicate planets on the mass–radius relationship and transmission and emission spectra. Methods. An interior–atmosphere model was combined with static structure calculations to track the evolving radius of a hot rocky planet that outgasses CO2 and H2O. We generated synthetic emission and transmission spectra for CO2 and H2O dominated atmospheres. Results. Atmospheres dominated by CO2 suppress the outgassing of H2O to a greater extent than previously realised since previous studies applied an erroneous relationship between volatile mass and partial pressure. We therefore predict that more H2O can be retained by the interior during the later stages of magma ocean crystallisation. Formation of a surface lid can tie the outgassing of H2O to the efficiency of heat transport through the lid, rather than the radiative timescale of the atmosphere. Contraction of the mantle, as it cools from molten to solid, reduces the radius by around 5%, which can partly be offset by the addition of a relatively light species (e.g. H2O versus CO2) to the atmosphere. Conclusions. A molten silicate mantle can increase the radius of a terrestrial planet by around 5% compared to its solid counterpart, or equivalently account for a 13% decrease in bulk density. An outgassing atmosphere can perturb the total radius, according to its composition, notably the abundance of light versus heavy volatile species. Atmospheres of terrestrial planets around M-stars that are dominated by CO2 or H2O can be distinguished by observing facilities with extended wavelength coverage (e.g. JWST).
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Nowak-Imialek, M., W. A. Kues, B. Petersen, A. Lucas-Hahn, D. Herrmann, E. Lemme, M. Oropeza, J. W. Carnwath, and H. Niemann. "333 OCT-4 EXPRESSION ANALYSIS IN F0 AND F1 PORCINE OG2 TRANSGENICS." Reproduction, Fertility and Development 23, no. 1 (2011): 262. http://dx.doi.org/10.1071/rdv23n1ab333.
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OG2 transgenic pigs provide a new large animal model in which to study Oct-4 expression and the derivation, migration and maintenance of pluripotent cells. They may also prove to be a valuable tool for the development of cell-based therapies. The OG2 transgene consists of the genomic sequence of the murine Oct-4 gene with the enhanced green fluorescence protein (EGFP) reporter gene inserted between the promoter and the coding sequences. As previously reported, 11 OG2 founder animals were produced (7 male and 4 female). Two of the OG2-F0 transgenic boars were mated with 3 wild-type sows and with 2 OG2-F0 transgenic sows. The pregnancy of 1 wild-type sow was terminated at Day 5 after fertilization, and approximately 60% (14/23) of the flushed blastocysts expressed EGFP, demonstrating germ line transmission. The remaining 2 wild-type sows delivered 21 piglets, of which 11 were transgenic. The 2 OG2-F0 sows delivered 9 piglets, all of which were transgenic. Transgenesis and tissue-specific expression of the transgene were determined by Southern blotting, Northern blotting, and real-time PCR analysis. Germ cell-specific expression of the OG2 construct was confirmed in both F0 and F1 transgenics by fluorescence microscopy. Testis isolated from male transgenic piglets exhibited weak EGFP fluorescence in some cells within the seminiferous tubules, whereas testis tissue from adult transgenic boars gave strong EGFP expression in pre-spermatogonial cells. In contrast, fluorescence-activated cell sorting (FACS) analysis and fluorescence microscopy of ejaculated spermatozoa from 3 mature OG2-F0 boars displayed no EGFP fluorescence, as expected. Northern blot analysis of EGFP mRNA revealed stronger EGFP expression in the testis of adult transgenic pigs than in the testis from transgenic piglets. No EGFP mRNA was detected in other organs or in control testis isolated from wild-type piglets. Real-time PCR and Northern blot analysis showed that the time course and signal intensity of EGFP expression in OG2 testis paralleled expression of the endogenous Oct-4 gene in both transgenic and in wild-type testis, confirming that there is indeed stronger expression of Oct-4 in the adult testis than in testis from younger animals. We conclude that the OG2 founders exhibit germline transmission and that the offspring express EGFP in a pattern that faithfully mimics expression of the endogenous Oct-4 gene, thus providing a marker for pluripotent cells. We are currently using FACS to isolate EGFP-positive germ cells (pre-spermatogonial stem cells) from the testis of OG2 boars for further characterisation. Funded by BMBF.
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Miranda-Medina, Maria de Lourdes, Christian Tomastik, Tia Truglas, Heiko Groiss, and Martin Jech. "Effect of engine oil additives reduction on the tribofilm structure of a cylinder liner model surface." Industrial Lubrication and Tribology 72, no. 4 (July 22, 2019): 515–23. http://dx.doi.org/10.1108/ilt-05-2019-0193.
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Purpose The purpose of this paper is to provide a general picture for describing the formed tribofilm, including chemical and physical aspects in the micro-scale and the nano-scale. In a previous study, the durability of zinc dialkyl dithiophosphate (ZDDP) tribofilms on cylinder liner samples has been investigated in a tribometer model system by using fresh and aged fully formulated oils and replacing them with PAO8 without additives. Analyses of the derived tribofilms by means of X-ray photoelectron spectroscopy and scanning electron microscopy could give some hints about the underlying mechanisms of the tribofilm build-up and wear performance, but a final model has not been achieved. Design/methodology/approach Thus, characterisation of these tribofilms by means of focused ion beam-transmission electron microscopy (FIB-TEM) and energy dispersive X-ray spectroscopy is presented and a concluding model of the underlying mechanisms of tribofilm build-up is discussed in this paper. Findings For tribotests running first with fresh fully formulated engine oil, a rather homogeneous ZDDP-like tribofilm is found underneath a carbon rich tribofilm after changing to non-additivated PAO8. However, when the tests run first with aged fully formulated engine oil, no ZDDP-like tribofilm has been found after changing to non-additivated PAO8, but a wear protective carbon rich tribofilm. Originality/value The obtained results provide insights into the structure and durability of tribofilms. Carbon-based tribofilms are built up on the basis of non-additivated PAO8 because of the previously present ZDDP tribofilms, which suggests an alternative way to reducing the consumption of antiwear additives.
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Garrels, W., S. Holler, N. Cleve, S. Klein, Z. Ivics, H. Niemann, D. Rath, and W. A. Kues. "329 FLOW CYTOMETRIC ANALYSIS OF SPERMATOZOA FROM REPORTER TRANSGENIC BOARS DERIVED BY PRECISION GENETIC ENGINEERING." Reproduction, Fertility and Development 25, no. 1 (2013): 312. http://dx.doi.org/10.1071/rdv25n1ab329.
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Recently, we produced 2 founder boars with a non-autonomous Sleeping Beauty (SB) system carrying 3 monomeric integrations of a Venus transposon cassette and showing transgene segregation during meiosis (Garrels et al. 2011 PLoS One 6, e27563). It was possible to show transmission of the reporter protein to fertilized oocytes by confocal microscopy. The aim of this study was to assess the suitability of different fluorophore reporters for in vivo labelling of pig spermatozoa. Therefore, we used Venus transposon fibroblasts from a F1 boar, which carry a single integration of the transposon cassette and used these fibroblasts for a Cre-mediated cassette exchange against an mCherry reporter. These cells were used for somatic cell nuclear transfer (SCNT) to derive a syngene clone cohort of boars, which differ only in the fluorophore reporter cDNAs (either Venus or mCherry). Importantly, this methodology did not request any antibiotic selection cassette and allows precise genetic modifications in a livestock species where no authentic embryonic stem cells are available (Garrels et al. 2012 Trends in Biotechnology 30, 386–393). A total of 8 male piglets carrying the Venus transposon, and 4 male piglets carrying the mCherry reporter were born. Three Venus boars and 2 mCherry boars were raised to sexual maturity, and ejaculated sperm was obtained with the help of a phantom. A detailed flow cytometric analysis revealed that the spermatozoa samples were specifically Venus or mCherry positive [Gallios, Beckmann Coulter, Krefeld, Germany; solid-state laser (488 nm; 22 mW), filter for green fluorescence (525 BP); filter for red fluorescence: (620/30)], respectively. In direct comparative measurements, the spermatozoa samples from transgenic boars (Venus and Cherry) and wildtype controls could be discriminated. Interestingly, spermatozoa were uniformly Venus- or mCherry-positive and gave a distinct fluorescence peak in flow-cytometric measurements. The monomeric transgenes were transmitted through the germ line according to Mendelian rules with the expected ratio of 50% transgenic and 50% nontransgenic piglets. Fluorescence microscopic analysis and Western blotting confirmed the uniform presence of Venus and mCherry in boar spermatozoa, respectively. This is the first characterisation of spermatozoa from a pig cohort carrying a targeted cassette exchange. This large animal model may help to elucidate the function of paternally transmitted components to fertilized oocytes.
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Houaidji, Naoual, Mejda Ajili, Baghdadi Chouial, Najoua Turki Kamoun, Kenza Kamli, Asma Khadraoui, Zakaria Hadef, Beddiaf Zaidi, and Bouzid Hadjoudja. "Study of Mn doping on the Structural, Optoelectronic and Photoluminescence Properties of F-Doped SnO2 Sprayed Thin Films for Optoelectronic Applications." Journal of Nano Research 65 (December 2020): 13–26. http://dx.doi.org/10.4028/www.scientific.net/jnanor.65.13.
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The aim of this work is the production and the characterisation of (SnO2: (Mn, F)) thin films with appropriate optoelectronic properties required for application as ohmic contacts in photovoltaic application devices. Transparent conducting Manganese-fluorine co-doped tin oxide (SnO2: (Mn, F)) thin films have been deposited onto preheated glass substrates using the chemical spray pyrolysis (CSP) method. The ([Mn2+]/[Sn4+]) atomic concentration ratio (y) in the spray solution is varied between 0 and 8 at. %. The structural, the opto-electrical and the photoluminescence properties of these thin films have been studied. It is found that the deposited thin films are polycrystalline with a tetragonal crystal structure corresponding to SnO2 phase having a preferred orientation along the (200) plane. Transmission and reflection spectra reveal the presence of interference fringes indicating the thickness uniformity and the surface homogeneity of the deposited samples. Photoluminescence behaviour of Mn-F co-doped SnO2 thin films was also studied. Photoluminescence spectra reveal the presence of the defects like oxygen vacancies in the materials. In addition, The electrical resistivity, volume carrier concentration, surface carrier concentration and electrical mobility were determined from Hall Effect measurements and the following results were obtained: n-type conductivity in all the deposited thin films, a low resistivity of 1.50×10-4 Ω cm, and a high electrical mobility of 45.40 cm2 V-1 s-1 with Mn co-doping concentration equals to 7 at. %. These experimental results show that the electrical properties of these thin films where greatly improved making them suitable as ohmic contacts in photovoltaic applications devices.
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Costa, P. M. F. J. "Imaging the stimuli response of nanostructured materials inside a transmission electron microscope: from today’s sub-second recording to ultrafast phenomena." Microscopy and Microanalysis 19, S4 (August 2013): 93–94. http://dx.doi.org/10.1017/s1431927613001086.
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Over the last decade, with the advent of aberration correctors and energy-filters, transmission electron microscopes (TEMs) have seen phenomenal developments both in regards to spatial and spectral resolutions. Today, the TEM is a characterisation tool pervasive to nanoscaled sciences and technologies. Imaging and identifying single atoms, including low Z elements such as B or C, is within reach of a skilful operator with access to this new generation of microscopes.Parallel to these advances, sample holders have also been evolving. Instead of just fixing and orienting the sample for observation, these ancillary components of TEMs have gradually been morphing into full-fledged instruments. Increasingly sophisticated devices enable a multitude of experiments performed inside the column of the TEM which includes the manipulation and exposure of discrete nanostructures to a variety of stimuli (heat, pressure, electrical current…). An example is the real-time observation of solid-vapour phase transitions in filled carbon nanotubes acting as interconnects and experiencing the dynamical effects of Joule heating. Together with resolution improvements, these added capabilities represent a paradigmatic shift in how we perceive and work with TEMs. No longer is the electron microscopist limited to simply analyse specimens in “post-mortem” state but (s)he can now take hold of a full set of physical and chemical experiments that encompass a much broader range of scientific interests.Despite all progress, there is a crucial part of the TEM capabilities that is still awaiting a similar leap in resolution: the time-domain. In result of the past dominance of “post-mortem” analysis, a temporal resolution enhancement has been overlooked by most instrument manufacturers and researchers. However, with the growing interest on in situ methodologies, the ability to perform time-resolved experiments has suddenly become a fundamental necessity. Classically, registering tools such as photographic films, charge-coupled devices or video-rated cameras have been adequate to acquire data on events that take place on timescales ranging from seconds to hours. Such temporal resolution is not sufficient for an immensity of life- and materials science-related processes. To illustrate this, Figure 1 shows the before and after states of a ZnS-filled carbon nanotube that was subjected to a pulse of electrical current. Although it is possible to observe clearly the end result, one can only speculate on how the confined semiconductor was released, transported and delivered to the receiving substrate. Considering that the pulse lasted for 250 ms, a temporal resolution of at least 50 ms (or 20 frames per second) for the registering device would be necessary to build a reasonable impression of the mechanism behind this delivery-procedure.PMFJC acknowledges the support from the Fundação para a Ciência e Tecnologia (Ciencia2007 Fellowship and project grant PTDC/EME-PME/112073/2009) and Alexander von Humboldt Foundation (Advanced Researcher Fellowship).
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Moldanová, J., E. Fridell, H. Winnes, S. Holmin-Fridell, J. Boman, A. Jedynska, V. Tishkova, et al. "Physical and chemical characterisation of PM emissions from two ships operating in European Emission Control Areas." Atmospheric Measurement Techniques Discussions 6, no. 2 (April 22, 2013): 3931–82. http://dx.doi.org/10.5194/amtd-6-3931-2013.
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Abstract. Emissions of particulate matter (PM) from shipping contribute significantly to the anthropogenic burden of PM. The environmental effects of PM from shipping include negative impact on human health through increased concentrations of particles in many coastal areas and harbour cities and the climate impact. The PM emitted by ship engines consists of organic carbon (OC), elemental or black carbon (EC/BC), sulphate, inorganic compounds containing V, Ni, Ca, Zn and other metals and associated water. The chemical composition and physical properties of PM vary with type of fuel burned, type of engine and engine operation mode. While primary PM emissions of species like V, Ni and Ca are supposed to be determined by composition of fuel and lubricant oil, emissions of particulate OC, EC and sulphate are affected both by fuel quality and by operation mode of the engine. In this paper a number of parameters describing emission factors (EFs) of gases and of particulate matter from ship engines were investigated during 2 on-board measurement campaigns for 3 different engines and 3 different types of fuels. The measured EFs for PM mass were in the range 0.3 to 2.7 g/kg-fuel with lowest values for emissions from combustion of marine gas oil (MGO) and the highest for heavy fuel oil (HFO). Emission factors for particle numbers EF(PN) in the range 5 × 1015–1 × 1017 #/kg-fuel were found, the number concentration was dominated by particles in the ultrafine mode and ca. 2/3 of particles were non-volatile. The PM mass was dominated by particles in accumulation mode. Main metal elements in case of HFO exhaust PM were V, Ni, Fe, Ca and Zn, in case of MGO Ca, Zn and P. V and Ni were typical tracers of HFO while Ca, Zn and P are tracers of the lubricant oil. EC makes up 10–38% of the PM mass, there were not found large differences between HFO and MGO fuels. EC and ash elements make up 23–40% of the PM mass. Organic matter makes up 25–60% of the PM. The measured EF(OC) were 0.59 ± 0.15 g/kg-fuel for HFO and 0.22 ± 0.01 g/kg-fuel for MGO. The measured EF(SO42−) were low, ca. 100–200 mg/kg-fuel for HFO with 1% fuel sulphur content (FSC), 70–85 mg/kg-fuel for HFO with 0.5% FSC and 3–6 mg/kg-fuel for MGO. This corresponds to 0.2–0.7% and 0.01–0.02% of fuel S converted to PM sulphate for HFO and MGO, respectively. The (scanning) transmission electron microscopy (TEM and STEM) images of the collected PM have shown three different types of particles: (1) soot composed mainly of C, O, sometimes N, and with traces of Si, S, V, Ca and Ni; (2) char and char-mineral particles composed of C, O, Ca and S (sometimes Si and Al) with traces of V and Ni and sometimes P and (3) amorphous, probably organic particles containing sulphur and some vanadium. The maps of elements obtained from STEM showed heterogeneous composition of primary soot particles with respect to the trace metals and sulphur. Composition of the char-mineral particles indicates that species like CaSO4, CaO and/or CaCO3, SiO2 and/or Al2SiO5, V2O5 and Fe3O4 may be present; the last two were also confirmed by analyses of FTIR spectra of the PM samples. The TPO of PM from the ship exhaust samples showed higher soot oxidation reactivity compared to automotive diesel soot, PM from the HFO exhaust is more reactive than PM from the MGO exhaust. This higher oxidation reactivity could be explained by high content of catalytically active contaminants; in particular in the HFO exhaust PM for which the energy-dispersive X-ray spectroscopy (EDXRF) analyses showed high content of V, Ni and S. Oxidative potential measured as a rate of consumption of consumption of Dithiothreitol (DTT) was for the first time measured on PM from ship exhaust. The obtained values were between 0.01 and 0.04 nmol-DTT/min/μg-PM, quite similar to oxidative potentials of PM collected in urban and traffic sites. The data obtained during the experiments add information on emission factors for both gaseous and PM-bound compounds from ship engines using different fuels and under different engine load conditions. Observed variability of the EFs illustrates uncertainties of these emission factors as a result of measurement uncertainties, influences from trace components of fuels and lubricants and from differences between individual engines.
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van der Vaart, Jelte, Lynn Bosmans, Hanneke Margo van Santen, Menno R. Vriens, and Hans Clevers. "Generation of Adult Stem Cell Derived Organoid Cultures From Thyroid Follicular Cells." Journal of the Endocrine Society 5, Supplement_1 (May 1, 2021): A850—A851. http://dx.doi.org/10.1210/jendso/bvab048.1736.
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Abstract The thyroid is essential for maintaining systemic homeostasis by regulating thyroid hormone concentrations in the bloodstream. Due to the limited number of representative model systems, there is limited understanding of fundamental thyroid biology as well as thyroid carcinogenesis. To fill the caveats in the understanding of thyroid cell biology, we aimed to develop an adult stem cell-derived three-dimensional (3D) organoid culture system using murine and human thyroid follicular cells (TFCs). We have succeeded to grow such an organoid culture system that harbours the complete machinery of hormone production visualised by the presence of colloid in the lumen and essential transporters and enzymes in a polarised cell layer. Both the established murine as human thyroid organoids express canonical thyroid markers PAX8 and NKX2.1/TTF1. Moreover, the thyroid hormone precursor thyroglobulin is expressed in both cultures to similar levels as in tissue. Extensive characterisation furthermore identifies known and new biological insights in TFC subclassification, subcellular organisation and hormone production using state-of-the art techniques like single cell RNA sequencing, transmission electron microscopy and genome editing. These 3D in vitro cultures allow for a variety of thyroid-related studies including the progression of wild type cells towards cancer. Additionally, due to the success of generating patient-specific tumour organoids of primary differentiated thyroid carcinoma and metastasis, insights in drug resistance and metastases can be identified. In short, this newly developed organoid culture of murine and human wild type TFCs as well as tumour tissue opens up an extensive area of research that will help understand the drivers for growth and development of thyroid (cancer) cells and enable studies upon drug responsiveness.
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Usui, Yuzo. "Transmission Line Loss." Journal of The Japan Institute of Electronics Packaging 22, no. 2 (March 1, 2019): 172–77. http://dx.doi.org/10.5104/jiep.22.172.
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Bajpai, Mr Priyanshu. "Wireless Transmission Line." International Journal for Research in Applied Science and Engineering Technology 7, no. 4 (April 30, 2019): 470–71. http://dx.doi.org/10.22214/ijraset.2019.4086.
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Grant, Ian S., and Roger E. Clayton. "Transmission Line Optimization." IEEE Power Engineering Review PER-7, no. 4 (April 1987): 61–62. http://dx.doi.org/10.1109/mper.1987.5527198.
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Grant, Ian S., and Roger E. Clayton. "Transmission Line Optimization." IEEE Transactions on Power Delivery 2, no. 2 (1987): 520–26. http://dx.doi.org/10.1109/tpwrd.1987.4308136.
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Carvalho, M. C. R., and W. Margulis. "Transmission line transformer." Electronics Letters 27, no. 2 (1991): 138. http://dx.doi.org/10.1049/el:19910090.
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