94 research outputs found

    Langer's axillary arch: a rare variant, and prevalence among Caucasians.

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    During the dissection of a 79-year-old Caucasian female cadaver, a variant of Langer's axillary arch was found unilaterally in the left axilla. While Langer's axillary arches are not uncommon, this particular variant, attaching to the biceps brachii, is much rarer with a reported prevalence of only 0.25%. The case reported here, however, is only the third example of a Langer's axillary arch that has been found in the last 14 years in the Dissecting Room at St. George's, University of London, giving it an overall prevalence of approximately 1.0% amongst a population of around 280 Caucasian cadavers, much lower than the reported frequency of 7%. Langer's axillary arches can be completely asymptomatic in life, but may also cause a variety of issues both clinically and surgically

    Enhanced magnetic properties in ZnCoAlO caused by exchangecoupling to Co nanoparticles

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    We report the results of a sequence of magnetisation and magneto-optical studies on laser ablated thin films of ZnCoAlO and ZnCoO that contain a small amount of metallic cobalt. The results are compared to those expected when all the magnetization is due to isolated metallic clusters of cobalt and with an oxide sample that is almost free from metallic inclusions. Using a variety of direct magnetic measurements and also magnetic circular dichroism we find that there is ferromagnetism within both the oxide and the metallic inclusions, and furthermore that these magnetic components are exchange-coupled when aluminium is included. This enhances both the coercive field and the remanence. Hence the presence of a controlled quantity of metallic nanoparticles in ZnAlO can improve the magnetic response of the oxide, thus giving great advantages for applications in spintronics

    Synthesis of iron-doped TiO2 nanoparticles by ball-milling process : the influence of process parameters on the structural, optical, magnetic, and photocatalytic properties

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    Titanium dioxide (TiO2) absorbs only a small fraction of incoming sunlight in the visible region thus limiting its photocatalytic efficiency and concomitant photocatalytic ability. The large-scale application of TiO2 nanoparticles has been limited due to the need of using an ultraviolet excitation source to achieve high photocatalytic activity. The inclusion of foreign chemical elements in the TiO2 lattice can tune its band gap resulting in an absorption edge red-shifted to lower energies enhancing the photocatalytic performance in the visible region of the electromagnetic spectrum. In this research work, TiO2 nanoparticles were doped with iron powder in a planetary ball-milling system using stainless steel balls. The correlation between milling rotation speeds with structural and morphologic characteristics, optical and magnetic properties, and photocatalytic abilities of bare and Fedoped TiO2 powders was studied and discussed.This work was partially financed by FCT-Fundacao para a Ciencia e Tecnologia-under the project PTDC/FIS/120412/2010: "Nanobased concepts for Innovative & Eco-sustainable constructive material's surfaces.

    Periodic density functional theory calculations of bulk and the (010) surface of goethite

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    <p>Abstract</p> <p>Background</p> <p>Goethite is a common and reactive mineral in the environment. The transport of contaminants and anaerobic respiration of microbes are significantly affected by adsorption and reduction reactions involving goethite. An understanding of the mineral-water interface of goethite is critical for determining the molecular-scale mechanisms of adsorption and reduction reactions. In this study, periodic density functional theory (DFT) calculations were performed on the mineral goethite and its (010) surface, using the Vienna <it>Ab Initio </it>Simulation Package (VASP).</p> <p>Results</p> <p>Calculations of the bulk mineral structure accurately reproduced the observed crystal structure and vibrational frequencies, suggesting that this computational methodology was suitable for modeling the goethite-water interface. Energy-minimized structures of bare, hydrated (one H<sub>2</sub>O layer) and solvated (three H<sub>2</sub>O layers) (010) surfaces were calculated for 1 Ă— 1 and 3 Ă— 3 unit cell slabs. A good correlation between the calculated and observed vibrational frequencies was found for the 1 Ă— 1 solvated surface. However, differences between the 1 Ă— 1 and 3 Ă— 3 slab calculations indicated that larger models may be necessary to simulate the relaxation of water at the interface. Comparison of two hydrated surfaces with molecularly and dissociatively adsorbed H<sub>2</sub>O showed a significantly lower potential energy for the former.</p> <p>Conclusion</p> <p>Surface Fe-O and (Fe)O-H bond lengths are reported that may be useful in surface complexation models (SCM) of the goethite (010) surface. These bond lengths were found to change significantly as a function of solvation (i.e., addition of two extra H<sub>2</sub>O layers above the surface), indicating that this parameter should be carefully considered in future SCM studies of metal oxide-water interfaces.</p

    Interface-induced phenomena in magnetism

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    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Effect of peer-teaching in learning and teaching anatomy: pilot study of the effect of introducing tutor training sessions

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    The use of peer-teaching has been well recognized as an effective tool within medical school curricula. Published literature provides some evidence of its advantages for both the tutor and the tutee. Often, in practice the planning and implementation of the peer-teaching sessions are left to the tutors with little or no guidance. This study aims to (i) investigate the effect of participation in peer-teaching on tutors’ anatomical knowledge with the application of a training program, (ii) evaluate the perceptions of peer-tutors and tutees of the effectiveness of the peer-teaching program. Ten term-2 medical students took part in three training sessions focusing on the clinical applications of the anatomy of the upper limb, thorax and abdomen prior to their peer-teaching sessions, which included 23 tutees. The questionnaire based assessment included: tutors appreciation of the relative anatomy assessed by 30 clinical vignettes, tutors and tutees perception of the peer-teaching experience measured by 23 and 12 questions, Likert-type-scale questionnaires respectively. Tutors perception correlated favorably with respect to improving their teaching abilities (mean scores of 3.5/5.0). The peer-teaching sessions were well received by the tutees; providing them with a student- perception and an alternative explanation of anatomical concepts (mean score of 3.7/5.0 and 3.8/5.0 respectively). Peer-teaching provides students with not only an opportunity to reinforce their anatomical knowledge, but also allows them to develop essential teaching skills and further develop various competencies. Creating a peer-teaching program allows for a clear learning strategy which can be implemented, evaluated and improved
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