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UCL University College London Eprints (375,347 recursos)

UCL Eprints collects the work of UCL researchers and makes it freely available over the web, helping the worldwide scholarly community to discover UCL research. Institutional repositories like UCL Eprints complement the traditional academic publishing and scholarly communications processes. They raise the visibility of research and help to maximise its impact. UCL researchers are encouraged to deposit a copy of each journal article, conference paper, working paper, and any other research output, in the UCL Eprints at the earliest opportunity, ensuring that their research reaches as wide an audience as possible.

Mostrando recursos 161 - 180 de 374,858

  1. Important factors determining the nanoscale tracking precision of dynamic microtubule ends.

    Bohner, G; Gustafsson, N; Cade, NI; Maurer, SP; Griffin, LD; Surrey, T
    Tracking dynamic microtubule ends in fluorescence microscopy movies provides insight into the statistical properties of microtubule dynamics and is vital for further analysis that requires knowledge of the trajectories of the microtubule ends. Here we analyse the performance of a previously developed automated microtubule end tracking routine; this has been optimized for comparatively low signal-to-noise image sequences that are characteristic of microscopy movies of dynamic microtubules growing in vitro. Sequences of simulated microtubule images were generated assuming a variety of different experimental conditions. The simulated movies were then tracked and the tracking errors were characterized. We found that the growth...

  2. Cost-Effectiveness of Apixaban versus Warfarin in Chinese Patients with Non-Valvular Atrial Fibrillation: A Real-Life and Modelling Analyses.

    Li, X; Tse, VC; Lau, WC; Cheung, BM; Lip, GY; Wong, IC; Chan, EW
    OBJECTIVES: Many of the cost-effectiveness analyses of apixaban against warfarin focused on Western populations but Asian evidence remains less clear. The present study aims to evaluate the cost-effectiveness of apixaban against warfarin in Chinese patients with non-valvular atrial fibrillation (NVAF) from a public institutional perspective in Hong Kong. METHODS: We used a Markov model incorporating 12 health state transitions, and simulated the disease progression of NVAF in 1,000 hypothetical patients treated with apixaban/warfarin. Risks of clinical events were based on the ARISTOTLE trial and were adjusted with local International Normalized Ratio control, defined as the time in therapeutic range. Real-life...

  3. On moments of the integrated exponential Brownian motion

    Caravelli, F; Mansour, T; Sindoni, L; Severini, S
    We present new exact expressions for a class of moments for the geometric Brownian motion, in terms of determinants, obtained using a recurrence relation and combinatorial arguments for the case of a Ito's Wiener process. We then apply the obtained exact formulas to computing averages of the solution of the logistic stochastic differential equation via a series expansion, and compare the results to the solution obtained via Monte Carlo.

  4. A novel lentiviral vector model to investigate the mechanism of insertional mutagenesis by aberrant splicing

    Doi, K; Collins, M; Takeuchi, Y


    Williams, E; Heeren, M; Jackson, CD; Pflugrad, H; Krause, J; Weber, LM; Wiessenborn, K; Morgan, MY

  6. Where do the differences in childhood mortality rates between England and Wales and Sweden originate?

    Zylbersztejn, AM; Gilbert, R; Hardelid, P; Hjern, A

  7. Left ventricular volume and ejection fraction determined by gated blood pool emission tomography.

    Underwood, SR; Walton, S; Laming, PJ; Jarritt, PH; Ell, PJ; Emanuel, RW; Swanton, RH
    Electrocardiogram gated single photon emission computed tomography of the intracardiac blood pools is a recent development that involves the acquisition of images in multiple projections after in vivo erythrocyte labelling with technetium-99m and reconstruction of these images into tomographic sections in any desired plane. The technique was used in 25 subjects to measure left ventricular volume, by summing the areas of the ventricle in each of the tomographic sections, and the results compared with those using a counts based (non-geometric) technique from planar radionuclide ventriculography. Endocardium was defined with the aid of a contour at 43% of maximum left ventricular...

  8. Quantitative phase analysis in the assessment of coronary artery disease.

    Underwood, SR; Walton, S; Laming, PJ; Ell, PJ; Emanuel, RW; Swanton, RH
    The phase image in radionuclide ventriculography shows the timing of ventricular contraction and is valuable in the detection of abnormalities induced by coronary artery disease. The image is usually interpreted subjectively, and in the present study a histogram of left ventricular phase values was used to make interpretation more objective. The left ventricular ejection fraction and the standard deviation, skewness, and kurtosis of the phase histogram were measured at rest, during isometric exercise, and during the final two stages of maximal dynamic exercise in 25 controls and 27 patients with coronary artery disease without previous infarction. The ejection fraction and...

  9. Whole-body imaging of thallium-201 after six different stress regimens.

    Pennell, DJ; Ell, PJ
    UNLABELLED: There are a number of stress techniques in common use for 201Tl myocardial imaging but few studies have been performed comparing the biodistribution of 201Tl in each case. METHODS: We studied 36 normal patients after six different stress regimens by whole-body imaging, 40 min after 201Tl injection. The stress regimens were exercise, dipyridamole, adenosine or dobutamine alone in standard doses and exercise combined with a vasodilator (dipyridamole or adenosine). RESULTS: Cardiac uptake expressed as a percentage of whole body uptake was greater for the vasodilators compared with exercise (p < 0.005), and this difference was unaffected by combining either...

  10. What can the life course approach contribute to an understanding of longevity risk?

    Blane, D; Akinwale, B; Landy, R; Matthews, K; Wahrendorf, M; Wahl, HW; Hayward, MD; Liefbroer, AC; Mishra, GD; Ferreira, I; Koupil, I
    © 2016, Society for Longitudinal and Life Course Studies. All rights reserved.Longevity risk means living longer than predicted. Attempts to understand longevity risk to date have concentrated on single diseases, usually coronary heart disease, and sought explanations in terms of risk factor change and medical innovation. In an opening paper, David Blane and colleagues point to evidence that suggests changes in positive health also should be considered; and that a life course approach can do so in a way that is socially and biologically plausible. Applying this approach to UK citizens currently aged 85 years suggests that life course research...

  11. Improved adhesion, growth and maturation of human bone-derived cells on nanocrystalline diamond films

    Kopecek, M; Bacakova, L; Vacik, J; Fendrych, F; Vorlicek, V; Kratochvilova, I; Lisa, V; Van Hove, E; Mer, C; Bergonzo, P; Nesladek, M
    Nanocrystalline diamond (NCD) films were deposited on microscopic glass slides using the MW PECVD method (20 Torr, 710°C, 0.8-1% CH 4). After the growth period, the films were oxidized and subsequently hydrogenated, and some of them were doped with boron (NCD-B; 3,000-30,000 ppm B:C; leading to ρ ∼ 10 -1 Ω cm for the highest doped films). The neutron depth profiling showed that in the near surface region (<800 nm) the boron ( 10B + 11B) content in the highest doped sample was about (1.9 ± 0.3) × 10 21 B cm -3 (i.e., 1.1 ±0.2 at% of B). The...

  12. First demonstration of heat dissipation improvement in CMOS technology using Silicon-On-Diamond (SOD) substrates

    Mazellier, JP; Widiez, J; Andrieu, F; Lions, M; Saada, S; Hasegawa, M; Tsugawa, K; Brevard, L; Dechamp, J; Rabarot, M; Delaye, V; Cristoloveanu, S; Clavelier, L; Deleonibus, S; Bergonzo, P; Faynot, O
    We have fabricated Silicon-On-Diamond (SOD) substrates on which, for the first time, we integrated n and p Fully Depleted MOSFETs high-K/metal gate down to 200nm gate length. The devices show excellent electrical characteristics and a 57% improvement of the thermal resistance compared to the co-processed one on standard SOI. © 2009 IEEE.

  13. Volunteering, choice and control: a case study of higher education student volunteering

    Holdsworth, C; Brewis, G
    There has been a step change around youth volunteering in the UK in recent years as this once unheralded and taken for granted activity has moved more centre stage, particularly as a key strand of recent Government initiatives directed towards welfare reform, employment and education policies. This article uses the case studies of student volunteering to explore the paradox inherent in articulations of volunteering in policy discourses that emphasise self-responsibility for employability and community cohesion. We review the tensions inherent in escalating the expectation that young people should volunteer through situating volunteering as a conduit of control society, and consider...

  14. Review of the development of diamond radiation sensors

    Adam, W; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, M; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P; Deneuville, A; Dulinski, W; Van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, KK; Gheeraert, E; Grigoriev, E; Hallewell, G; Hall-Wilton, R; Han, S; Hartjes, F; Hrubec, J; Husson, D; Kagan, H; Kania, D; Kaplon, J; Karl, C; Kass, R; Knöpfle, KT; Krammer, M; Logiudice, A; Lu, R; Manfredi, PF; Manfredotti, C; Marshall, RD; Meier, D; Mishina, M; Oh, A; Pan, LS; Palmieri, VG; Pernicka, M; Peitz, A; Pirollo, S; Polesello, P; Pretzl, K; Re, V; Riester, JL; Roe, S; Roff, D; Rudge, A; Schnetzer, S; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, RJ; Tesarek, R; Thomson, GB; Trawick, M; Trischuk, W; Vittone, E; Walsh, AM; Wedenig, R; Weilhammer, P; Ziock, H; Zoeller, M
    Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 μm have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9×1015 π cm-2, 5×1015 p cm-2 and 1.35×1015 n cm-2, respectively. Diamond micro-strip detectors with 50 μm pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip...

  15. Diamond dosimeter for small beam stereotactic radiotherapy

    Marsolat, F; Tromson, D; Tranchant, N; Pomorski, M; Lazaro-Ponthus, D; Bassinet, C; Huet, C; Derreumaux, S; Chea, M; Boisserie, G; Alvarez, J; Bergonzo, P
    Recent developments of new therapy techniques using small photon beams, such as stereotactic radiotherapy, require new detectors to precisely determine the delivered dose. The dosimeter has to be as close as possible to tissue equivalence and exhibit a small detection volume compared to the size of the irradiation field, because of the lack of lateral electronic equilibrium in small beam. Characteristics of single crystal diamond (tissue equivalent material Z = 6, high density) make it an ideal candidate to fulfill most of small beam dosimetry requirements. A commercially Element Six electronic grade synthetic diamond was selected to develop a single...

  16. High reactivity and stability of diamond electrodes: The influence of the B-doping concentration

    Vanhove, E; De Sanoit, J; Mailley, P; Pinault, MA; Jomard, F; Bergonzo, P
    The use of diamond to develop electrochemical (EC) sensors opens up promising perspectives with interests for biosensing applications. However, in spite of the superior EC properties of diamond, two crucial issues remain to be solved: to improve (i) the electrode stability and (ii) the charge transfer rate k 0. To address these issues, the influence of the boron concentration and of EC treatments on EC behaviour was assessed. Our results were compared with those obtained on a commercial diamond electrode. The reactivity of the as-grown electrodes was very high whatever the boron concentration. However, a systematic linear increase of the...

  17. Selective nucleation in silicon moulds for diamond MEMS fabrication

    Bongrain, A; Scorsone, E; Rousseau, L; Lissorgues, G; Gesset, C; Saada, S; Bergonzo, P
    We present a new and original approach for the fabrication of diamond MEMS using MPCVD. This process does not rely on diamond etching using conventional techniques such as e.g. RIE: here our MEMS structures are geometrically defined using silicon moulds in which diamond is grown selectively. The moulds can be prepared from silicon using DRIE and enabling a wide range of geometries. The critical point is the selectivity of diamond growth which dramatically depends on the nucleation process. Two nucleation methods for selective diamond growth inside silicon moulds were explored in parallel and compared, namely, the bias enhanced nucleation (BEN)...

  18. Surface science contribution to the BEN control on Si(100) and 3C-SiC(100): Towards ultrathin nanocrystalline diamond films

    Arnault, JC; Saada, S; Delclos, S; Rocha, L; Intiso, L; Polini, R; Hoffman, A; Michaelson, S; Bergonzo, P
    Deposition of thin and smooth nanocrystalline diamond films requires a high degree of control of the nucleation stage. The nature of the interface between diamond film and substrate is also important for some applications. The successive steps of the bias-enhanced nucleation (BEN) process are studied in-situ on Si(100) and 3C-SiC(100) using electron spectroscopies. Thin nanodiamond films (80-900 nm) have been achieved on Si(100). The formation of a thin covering SiC layer (2-3 nm) during the plasma exposure for parameters stabilization (PEPS) step leads us to study the plasma/surface interactions on 3C-SiC(100) surfaces. The C-terminated 3C-SiC(100) demonstrates a large inertia under...

  19. Addressing Energy Poverty and Vulnerable Consumers in the Energy Sector Across the EU

    Pye, S; Dobbins, A; Baffert, C; Brajković, J; Deane, P; De Miglio, R

  20. Information-based asset pricing

    Brody, DC; Hughston, LP; Macrina, A
    © 2013 by World Scientific Publishing Co. Pte. Ltd. All rights reserved.A new framework for asset price dynamics is introduced in which the concept of noisy information about future cash flows is used to derive the corresponding price processes. In this framework an asset is defined by its cash-flow structure. Each cash flow is modelled by a random variable that can be expressed as a function of a collection of independent random variables called market factors. With each such “X-factor” we associate a market information process, the values of which we assume are accessible to market participants. Each information process...

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