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UCL University College London Eprints (411.275 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 1 - 20 de 63.035

  1. Adenosine-guided pulmonary vein isolation versus conventional pulmonary vein isolation in patients undergoing atrial fibrillation ablation: An updated meta-analysis

    Papageorgiou, N; Providencia, R; Srinivasan, N; Bronis, K; Costa, FM; Cavaco, D; Adragao, P; Tousoulis, D; Hunter, RJ; Schilling, RJ; Segal, OR; Chow, A; Rowland, E; Lowe, M; Lambiase, PD
    BACKGROUND: Recurrent atrial fibrillation episodes following pulmonary vein isolation (PVI) are frequently due to reconnection of PVs. Adenosine can unmask dormant conduction, leading to additional ablation to improve AF-free survival. We performed a meta-analysis of the literature to assess the role of adenosine testing in patients undergoing atrial fibrillation (AF) ablation. METHODS: PubMed, EMBASE, and Cochrane databases were searched through until December 2015 for studies reporting on the role of adenosine guided-PVI versus conventional PVI in AF ablation. RESULTS: Eleven studies including 4099 patients undergoing AF ablation were identified to assess the impact of adenosine testing. Mean age of the population was...

  2. Electrocardiographic differentiation of idiopathic right ventricular outflow tract ectopy from early arrhythmogenic right ventricular cardiomyopathy

    Novak, J; Zorzi, A; Castelletti, S; Pantasis, A; Rigato, I; Corrado, D; Mckenna, W; Lambiase, PD
    Aims: The differentiation between idiopathic right ventricular outflow tract (RVOT) arrhythmias and early arrhythmogenic right ventricular cardiomyopathy (ARVC) can be challenging. We aimed to assess whether QRS morphological features and coupling interval of ventricular ectopic beats (VEBs) can improve differentiation between the two conditions. Methods and Results: Twenty desmosomal-gene mutation carriers (13 females, mean age 43 years) with no or mild ARVC phenotypic expression and 33 age- and sex-matched subjects with idiopathic RVOT arrhythmias were studied. All patients exhibited isolated monomorphic VEBs with left bundle branch block/inferior axis morphology. The predictive value of ectopic QRS morphology and coupling interval was...

  3. Lithium isotopes in speleothems: Temperature-controlled variation in silicate weathering during glacial cycles

    Pogge von Strandmann, PAE; Vaks, A; Bar-Matthews, M; Ayalon, A; Jacob, E; Henderson, GM
    Terrestrial chemical weathering of silicate minerals is a fundamental component of the global cycle of carbon and other elements. Past changes in temperature, rainfall, ice cover, sea-level and physical erosion are thought to affect weathering but the relative impact of these controls through time remains poorly constrained. This problem could be addressed if the nature of past weathering could be constrained at individual sites. In this study, we investigate the use of speleothems as local recorders of the silicate weathering proxy, Li isotopes. We analysed δ7Li and [Li] in speleothems that formed during the past 200 ka in two well-studied...

  4. Tailored emails prompt electric vehicle owners to engage with tariff switching information

    Nicolson, M; Huebner, GM; Shipworth, D; Elam, S
    The carbon intensity of the electricity used to charge an electric vehicle (EV) is dependent on when in the day charging occurs. However, persuading EV owners to adopt incentives to charge during off-peak hours is challenging. Here we show that governments could exploit the ‘window of opportunity’ created when people purchase their first EV to promote time-of-use tariffs. Email recipients (n = 7,038 EV owners) were more likely to click-through to an information webpage when the email emphasized specific reductions in home-charging costs versus general bill savings. However, the ‘window of opportunity’ for maximizing potential adoption is short; email open rates...

  5. Eliciting web site preferences of people with learning disabilities

    Williams, P
    The Internet can be an excellent tool to help people with learning disabilities access relevant and appropriately written information. However, little work has been undertaken to ascertain web design or content preferences for this cohort. This paper examines methods to address this issue. Twenty five participants were presented with three web sites dealing with employment information. They were asked to browse each and carry out a series of set-tasks. Interviews and a rating scale ascertained preferences. The problem of acquiescence bias, the tendency for people to automatically agree with those in perceived positions of authority, was minimised by the avoidance...

  6. Why are there discrepancies between depressed patients' Global Rating of Change and scores on the Patient Health Questionnaire depression module? A qualitative study of primary care in England

    Robinson, J; Khan, N; Fusco, L; Malpass, A; Lewis, G; Dowrick, C
    OBJECTIVES: Our aims were to investigate discrepancies between depressed patients' GlobalRating of Change (GRC) and scores on the Patient Health Questionnaire depression module (PHQ-9). Our objectives were to ascertain patients' views on the source and meaning of mismatches and assess their clinical significance. DESIGN: Qualitative study nested within a cohort, in a programme investigating the indications for prescribing antidepressants that will lead to a clinical benefit. SETTING: Primary care practices in north-west England. PARTICIPANTS: We invited 32 adults with a recent diagnosis of depression and evidence of mismatch between GRC and PHQ-9 Scores to participate. Of these, 29 completed our...

  7. Essential Oil Bioactive Fibrous Membranes Prepared via Coaxial Electrospinning

    Yao, Z-C; Chen, S-C; Ahmad, Z; Huang, J; Chang, M-W; Li, J-S
    A novel antimicrobial composite material was prepared by encapsulating orange essential oil (OEO) in zein prolamine (ZP) via the coaxial electrospinning (ES) technique. By manipulating process parameters, the morphological features of ZP/OEO fibers were modulated. Fine fibers with diameters ranging from 0.7 to 2.3 μm were obtained by regulating ZP solution concentration and process parameters during the ES process. Optimal loading capacity (LC) and encapsulation efficiency (EE) of OEO in fibrous ZP mats were determined to be 22.28% and 53.68%, respectively, and were achieved using a 35 w/v% ZP ES solution. The encapsulation of OEO was found to be reliant...

  8. Ganoderma lucidum polysaccharide loaded sodium alginate micro-particles prepared via electrospraying in controlled deposition environments

    Yao, Z-C; Jin, L-J; Ahmad, Z; Huang, J; Chang, M-W; Li, J-S
    Ganoderma lucidum polysaccharide (GLP) is a functional food source deployed in preventative medicine. However, applications utilizing GLP are limited due to oxidative and acidic environmental damage. Advances in preserving GLP structure (and therefore function), in situ, will diversify their applications within biomedical fields (drug and antibacterial active delivery via the enteral route). In this study, GLP loaded sodium alginate (NaAlg) micro-particles (size range 225–355 μm) were generated using the electrospray (ES) process. The loading capacity and encapsulation efficiency of GLP for composite particles (collected at different temperatures) were ∼23% and 71%, respectively. The collection substrate (CaCl2, 1–20 w/v%) concentration was...

  9. Non-concentric multi-compartment fibers fabricated using a modified nozzle in single-step electrospinning

    Wang, B; Wang, M; Chang, M-W; Ahmad, Z; Huang, J; Li, J-S
    Multi-compartment fibers with well-defined regions and functional media hosting potential provide co-encapsulation opportunities for a variety of bio-molecules, drugs and even nutrients. In this research, fibers possessing multiple compartments were prepared using the single-step electrospinning method and a modified non-concentric multi-needle. Polyvinyl pyrrolidone (PVP) was used as the fiber shell material, while ketoconazole (KCZ, model drug) and Sudan Red (model probe) were encapsulated as two separate segments running along the fiber length. Multi-compartment fiber morphology and structure were examined using optical and electron microscopy. The effect of flow rate on fiber morphology was also investigated and the release of encapsulated...

  10. Famine, conflict, and political indifference

    Seal, A; Hailey, P; Bailey, R; Maxwell, D; Majid, N

  11. Performance of the Xpert MTB/RIF assay in the diagnosis of tuberculosis in formalin-fixed, paraffin-embedded tissues

    Polepole, P; Kabwe, M; Kasonde, M; Tembo, J; Shibemba, A; O'Grady, J; Kapata, N; Zumla, A; Bates, M
    OBJECTIVE/BACKGROUND: Extrapulmonary tuberculosis (EPTB), which accounts for 10%-40% of the global burden of TB, with the highest incidence in Sub-Saharan Africa, is strongly associated with human immunodeficiency virus infection. Diagnosing EPTB is challenging, and recently, there has been a concerted effort to evaluate the latest molecular diagnostics for diagnosing TB in a range of specimen types. The Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) is one such technology, which simultaneously detects Mycobacterium tuberculosis and rifampicin resistance. Our objective was to evaluate the accuracy of the Xpert MTB/RIF assay for the diagnosis of EPTB and detection of rifampicin resistance in routinely...

  12. Resolution limit of cylinder diameter estimation by diffusion MRI: The impact of gradient waveform and orientation dispersion

    Nilsson, M; Lasič, S; Drobnjak, I; Topgaard, D; Westin, C-F
    Diffusion MRI has been proposed as a non-invasive technique for axonal diameter mapping. However, accurate estimation of small diameters requires strong gradients, which is a challenge for the transition of the technique from preclinical to clinical MRI scanners, since these have weaker gradients. In this work, we develop a framework to estimate the lower bound for accurate diameter estimation, which we refer to as the resolution limit. We analyse only the contribution from the intra-axonal space and assume that axons can be represented by impermeable cylinders. To address the growing interest in using techniques for diffusion encoding that go beyond...

  13. Managing outpatient consultations: from referral to discharge.

    Mitchell, R; Jacob, H; Morrissey, B; Macaulay, C; Gomez, K; Fertleman, C
    Although a great deal of paediatric consultations are not urgent, doctors in training spend so much time providing service for acute conditions that they spend little time focusing on outpatient work before they become a consultant. Engaging clinicians in the managerial aspects of providing clinical care is a key to improving outcomes, and this article addresses these aspects of the outpatient consultation from referral to discharge. We aim to provide doctors in training with a tool to use during their training and their first few years as a consultant, to think about how outpatient work is organised and how it...

  14. Reading, Writing, and the Regrettable Status of Education Research in Comparative Politics

    Gift, T; Wibbels, E
    Apart from some notable exceptions, education is regrettably understudied in comparative politics. This paucity stems from both a dearth of reliable data on schooling and the fact that education raises analytical issues that fall outside the typical domain of political scientists. In light of education's crucial role in everything from citizen attitudes to earnings to economic growth, we recommend that political scientists pay more attention to education. In particular, comparative researchers should shift from an almost exclusive focus on average levels of schooling to explaining the causes and consequences of educational inequality. To that end, we provide a broad comparative...

  15. Low temperature plasma-enhanced atomic layer deposition of metal oxide thin films

    Potts, SE; Keuning, W; Langereis, E; Dingemans, G; Van De Sanden, MCM; Kessels, WMM
    Many reported atomic layer deposition (ALD) processes are carried out at elevated temperatures (>150°C), which can be problematic for temperature-sensitive substrates. Plasma-enhanced ALD routes may provide a solution, as the ALD temperature window can, in theory, be extended to lower deposition temperatures due to the reactive nature of the plasma. As such, the plasma-enhanced ALD of Al2 O3, TiO2, and Ta2 O5 has been investigated at 25-400°C using [Al (CH3)3], [Ti (OPir)4], [Ti(Cp Me) (OiPr)3], [TiCp* (OMe)3], and [Ta (NMe2)5] as precursors. An O2 plasma was employed as the oxygen source in each case. We have demonstrated metal oxide thin-film...

  16. A solution to the 2/3 conjecture

    Talbot, JM; Baber, R
    We prove a vertex domination conjecture of Erd˝os, Faudree, Gould, Gy´arf´as, Rousseau, and Schelp that for every n-vertex complete graph with edges colored using three colors there exists a set of at most three vertices which have at least 2n/3 neighbors in one of the colors. Our proof makes extensive use of the ideas presented in [D. Kr´al’ et al., A new bound for the 2/3 conjecture, Combin. Probab. Comput. 22 (2013), pp. 384–393].

  17. Children’s musical and social behaviours in the context of music-making activities supported by digital tools: Examples from a pilot study in the United Kingdom

    Charissi, V; Rinta, T
    Children’s enjoyable experience in music-making has been reported to be crucial for their social and musical development. This research investigates the way in which participant young children develop their musical and social skills by digital technology-supported music-making activities within a multicultural educational context. Two different software packages were used in the research. Data collection methods reported in the current article included observations and field notes, video analyses and dialogue analyses. Initial results indicate that children developed their musical knowledge as a part of their active interaction with others. In particular, their use of digital tools provided a supportive environment for...

  18. Virologic Response to First-Line Efavirenz- or Nevirapine-Based Anti-Retroviral Therapy in HIV-Infected African Children

    Kekitiinwa, A; Szubert, AJ; Spyer, M; Katuramu, R; Musiime, V; Mhute, T; Bakeera-Kitaka, S; Senfuma, O; Walker, AS; Gibb, DM; ARROW Trial Team, .
    BACKGROUND: Poorer virologic response to nevirapine vs efavirenz-based antiretroviral therapy (ART) has been reported in adult systematic reviews and pediatric studies. METHODS: We compared drug discontinuation and viral load (VL) response in ART-naïve Ugandan/Zimbabwean children ≥3 years of age initiating ART with clinician-chosen nevirapine vs efavirenz in the ARROW trial. Predictors of suppression <80, <400 and <1000 copies/ml at 36, 48 and 144 weeks were identified using multivariable logistic regression with backwards elimination (p=0.1). RESULTS: 445(53%) children received efavirenz and 391(47%) nevirapine. Children receiving efavirenz were older (median 8.6 years vs 7.5 nevirapine, p<0.001) and had higher CD4% (12% vs...

  19. Mindfulness within Educational Psychology Practice: possibilities and constraints

    Iyadurai, S; Morris, J; Dunsmuir, SM

  20. Measuring Gender inequality and equality in education

    Unterhalter, ES
    Since 1995, considerable expertise has built up in measuring aspects of gender inequality and equality, and in researching these in education, particularly formal schooling. Existing international and national measures used for reporting on gender in formal schooling chart gender parity in school enrolment, attendance, progression, and learning outcomes. Gender parity measures the number of girls as a proportion of the number of boys. This measure generates some insights regarding the distribution and use of resources, but it is narrow. However, gender parity as a measurement technique tells us very little about the institutions which help reproduce gender inequalities within and beyond education. It also fails to give...

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