2,731 research outputs found

    A quality improvement programme in radiotherapy using workflow audits

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    Background. Evaluation of the quality of healthcare depends on measures of structures, processes and outcomes. Progress in recording data allows for better measures of processes, such as the completeness of clinical data, the performance of professional tasks and the use of checklists.Objectives. To report the results of a radiotherapy (RT) workflow audit and a subsequent online survey of user experience.Methods. The RT workflow audit was developed in 2016 and has been undertaken twice a year at 28 facilities or units, with a total of 32 linear accelerators. Electronic patient folders were reviewed to assess the documentation of 90 task items, of which 64 were scored. The auditor came from another facility. The online survey took place in July 2020. It contained questions on the audit’s process, professional value and future use. Invitations were sent by email to the 151 radiotherapist staff at the 28 units where the audit had been implemented. Responses were anonymous.Results. For the RT workflow audit, scores improved from 60% in some units in 2016 to >90% in all units for at least 2 years since 2018. The number of responders to the online survey was 58, giving a responder rate of 38%. The margin of error of the results was 10%. The audit’s task items were considered appropriate by 77% of responders, and feedback was reported by 78% of them. The audit was considered very or extremely valuable to their unit’s service delivery by 58% of responders. Changes in the unit as a result of the audit were reported by 77% of responders. The audit was very useful or extremely useful to 75% of responders in maintaining personal professional standards. The proportion of responders who were very or extremely supportive of continuing with the audit was 77%. The comments in the online survey will be helpful for ongoing review of the RT workflow audit.Conclusions. The RT workflow audit extends the scope of accreditation audits by including measures of processes. Users of the audit evaluate its processes favourably and report that it has value both in their unit’s clinical service and for their personal professional standards. The audit is effective in developing quality improvement programmes

    Microevolution of serial clinical isolates of Cryptococcus neoformans var. grubii and C. gattii

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    This is the final version. Available from the publisher via the DOI in this record.The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in subSaharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis.Wellcome TrustNational Institute of Allergy and Infectious Disease

    Audits of oncology units – an effective and pragmatic approach

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    CITATION: Abratt, R. P., et al. 2017. Audits of oncology units – an effective and pragmatic approach. South African Medical Journal, 107(6):493-496, doi:10.7196/SAMJ.2017.v107i6.12356.The original publication is available at http://www.samj.org.za/index.php/samjBackground. Audits of oncology units are part of all quality-assurance programmes. However, they do not always come across as pragmatic and helpful to staff. Objective. To report on the results of an online survey on the usefulness and impact of an audit process for oncology units. Methods. Staff in oncology units who were part of the audit process completed the audit self-assessment form for the unit. This was followed by a visit to each unit by an assessor, and then subsequent personal contact, usually via telephone. The audit self-assessment document listed quality-assurance measures or items in the physical and functional areas of the oncology unit. There were a total of 153 items included in the audit. The online survey took place in October 2016. The invitation to participate was sent to 59 oncology units at which staff members had completed the audit process. Results. The online survey was completed by 54 (41%) of the 132 potential respondents. The online survey found that the audit was very or extremely useful in maintaining personal professional standards in 89% of responses. The audit process and feedback was rated as very or extremely satisfactory in 80% and 81%, respectively. The self-assessment audit document was scored by survey respondents as very or extremely practical in 63% of responses. The feedback on the audit was that it was very or extremely helpful in formulating improvement plans in oncology units in 82% of responses. Major and minor changes that occurred as a result of the audit process were reported as 8% and 88%, respectively. Conclusion. The survey findings show that the audit process and its self- assessment document meet the aims of being helpful and pragmatic.http://www.samj.org.za/index.php/samj/article/view/11919Publisher's versio

    A biomechanical study on the effect of long head of biceps tenotomy on supraspinatus load and humeral head position during shoulder abduction

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    INTRODUCTION : The purpose of this study was to determine the effect of biceps tendon tenotomy on the load of the supraspinatus tendon/muscle complex during abduction of the arm from 0° to 15°. METHODS : Eleven fresh frozen human cadaver shoulders (6 males, 5 females, age ranged 44-88 years, mean upper extremity weight 2.96 ¹ 0.56 kg) were included. The specimens were sequentially mounted onto a custom-made fixture attached to a pulley system and load cell. The pulley system was used to pull the supraspinatus tendon/muscle complex along its fiber directions to abduct the arm to 15°. Abduction angles were recorded with a digital inclinometer. Two conditions were tested: (1) long head biceps tendon (LHBT) intact and in normal anatomical position; (2) LHBT cut within the bicipital groove. Qualitative visual inspection of humeral head displacement during abduction was also included. Descriptive statistics were calculated. The Shapiro-Wilk test was used to establish normal data distribution, and the paired t-test was used to compare the 2 conditions. RESULTS : For the intact condition (LHBT intact), the mean load was 45.71 ¹ 21.04 N. For the biceps tenotomy test, the load measured 41.37 ¹ 23.43 N. These differences were not significant (P = .1480). In the tenotomy condition, the humeral head initially displaced inferior, and with initiation of abduction, the humeral head translated superior to its normal position. CONCLUSION : The results suggest that the LHBT has no critical role with initial abduction of the arm. Furthermore, the LHBT does not appear to increase loads required for the supraspinatus muscle/tendon complex to perform the same action of abduction.The National Research Foundation.http://www.elsevier.com/locate/ymsehj2023Anatom

    Seedless Pattern Growth of Quasi-Aligned ZnO Nanorod Arrays on Cover Glass Substrates in Solution

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    A hybrid technique for the selective growth of ZnO nanorod arrays on wanted areas of thin cover glass substrates was developed without the use of seed layer of ZnO. This method utilizes electron-beam lithography for pattern transfer on seedless substrate, followed by solution method for the bottom-up growth of ZnO nanorod arrays on the patterned substrates. The arrays of highly crystalline ZnO nanorods having diameter of 60 ± 10 nm and length of 750 ± 50 nm were selectively grown on different shape patterns and exhibited a remarkable uniformity in terms of diameter, length, and density. The room temperature cathodluminescence measurements showed a strong ultraviolet emission at 381 nm and broad visible emission at 585–610 nm were observed in the spectrum

    Irreversible depletion of intestinal CD4+ T cells is associated with T cell activation during chronic HIV infection

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    HIV infection in the human gastrointestinal (GI) tract is thought to be central to HIV progression, but knowledge of this interaction is primarily limited to cohorts within Westernized countries. Here, we present a large cohort recruited from high HIV endemic areas in South Africa and found that people living with HIV (PLWH) presented at a younger age for investigation in the GI clinic. We identified severe CD4(+) T cell depletion in the GI tract, which was greater in the small intestine than in the large intestine and not correlated with years on antiretroviral treatment (ART) or plasma viremia. HIV-p24 staining showed persistent viral expression, particularly in the colon, despite full suppression of plasma viremia. Quantification of mucosal antiretroviral (ARV) drugs revealed no differences in drug penetration between the duodenum and colon. Plasma markers of gut barrier breakdown and immune activation were elevated irrespective of HIV, but peripheral T cell activation was inversely correlated with loss of gut CD4(+) T cells in PLWH alone. T cell activation is a strong predictor of HIV progression and independent of plasma viral load, implying that the irreversible loss of GI CD4(+) T cells is a key event in the HIV pathogenesis of PLWH in South Africa, yet the underlying mechanisms remain unknown

    Brane-World Gravity

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    The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+\textit{d}-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the \textit{d} extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∟\sim TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall--Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at \emph{low} energies -- the 5-dimensional Dvali--Gabadadze--Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.Comment: A major update of Living Reviews in Relativity 7:7 (2004) "Brane-World Gravity", 119 pages, 28 figures, the update contains new material on RS perturbations, including full numerical solutions of gravitational waves and scalar perturbations, on DGP models, and also on 6D models. A published version in Living Reviews in Relativit

    Face-selective electrostatic control of hydrothermal zinc oxide nanowire synthesis

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    Rational control over the morphology and the functional properties of inorganic nanostructures has been a long-standing goal in the development of bottom-up device fabrication processes. We report that the geometry of hydrothermally grown zinc oxide nanowires can be tuned from platelets to needles, covering more than three orders of magnitude in aspect ratio (~0.1–100). We introduce a classical thermodynamics-based model to explain the underlying growth inhibition mechanism by means of the competitive and face-selective electrostatic adsorption of non-zinc complex ions at alkaline conditions. The performance of these nanowires rivals that of vapour-phase-grown nanostructures and their low-temperature synthesis (<60 °C) is favourable to the integration and in situ fabrication of complex and polymer-supported devices. We illustrate this capability by fabricating an all-inorganic light-emitting diode in a polymeric microfluidic manifold. Our findings indicate that electrostatic interactions in aqueous crystal growth may be systematically manipulated to synthesize nanostructures and devices with enhanced structural control.National Science Foundation (U.S.) (MIT Center for Bits and Atoms (NSF CCR0122419))Massachusetts Institute of Technology. Media LaboratoryKorea Foundation for Advanced StudiesSamsung Electronics Co. (research internship)Harvard University. Society of FellowsWallace H. Coulter Foundation (Early Career Award)Brain & Behavior Research Foundation (Young Investigator Award)National Science Foundation (U.S.)National Institutes of Health (U.S.) (Director’s New Innovator Award

    Facile Synthesis of ZnO Nanorods by Microwave Irradiation of Zinc–Hydrazine Hydrate Complex

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    ZnO nanorods have been successfully synthesized by a simple microwave-assisted solution phase approach. Hydrazine hydrate has been used as a mineralizer instead of sodium hydroxide. XRD and FESEM have been used to characterize the product. The FESEM images show that the diameter of the nanorods fall in the range of about 25–75 nm and length in the range of 500–1,500 nm with an aspect ratio of about 20–50. UV–VIS and photoluminescence spectra of the nanorods in solution have been taken to study their optical properties. A mechanism for microwave synthesis of the ZnO nanorods using hydrazine hydrate precursor has also been proposed
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