6,241 research outputs found

    Numerical evaluation of shear strength of CFS shear wall panels for different height-to-width ratios

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    This paper presents a numerical evaluation of the shear strength of Cold Formed Steel Shear Wall Panels (CFS-SWPs) having 1.33:1 and 1:1 height-to-width aspect ratios with 0.76 mm steel plate sheathing thickness and 1:4,  1.33:1 and 1:1  height-to-width aspect ratios with 0.46 mm steel plate sheathing thickness, which are not provided by AISI S400. For this purpose, shell finite element (FE) models, validated with test results, are completed in ABAQUS v2018 with nonlinear geometry, material and connection. A good agreement is achieved between experimental and numerical results in terms of shear strength-lateral displacement and failure modes.It is concluded that, for a fixed height-to-width aspect ratio, the shear strength of SWPs having different screws spacing varying from 50.4 mm up to 152.4 can be assessed by interpolation using this FE method. However, by interloping the shear strength from 4:1 to 1:1 height-to-width aspect ratio, the shear strength can be underestimated; hence, it is more economical for practicing engineers to use the shear strength assessed by this proposed FE method for 1.33:1 and 1:1 height-to-width aspect ratios. Moreover, the effect of the sheathing thickness having 0.46 mm is evaluated and proposed as it lacks in data provided by the code (i.e., AISI S400)

    Investigation of ultrasonic neuro-stimulation effects in peripheral axons

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    Appreciation for the medical and research potential of ultrasound neuromodulation is growing rapidly, with potential applications in non-invasive treatment of neuro-degenerative disease and functional brain mapping spurring recent progress. A full understanding of the mechanical interaction of sound waves and neural tissue could allow tailor-made stimuli to produce different effects or specifically stimulate separate tissue types, adding great value to an already promising technique. Despite this worthy goal, little progress has been made in our understanding of the nature of the ultrasound-tissue interaction. The current study forms part of a long term goal to tackle this issue by isolating and characterising the effects of, and sensitivity to ultrasound for all the different structures found in nervous tissue. A simple, well characterised model of nervous transmission is therefore used along with a tightly controlled acoustic environment so that the characteristics of direct US stimulation effects can be investigated. Experiments are performed that demonstrate the capability of ultrasound to directly stimulate unmyelinted peripheral axons, characterise the stimulus response dynamics and determine the responsible ultrasonic force mechanism. A PCD, unimpeded ultrasound path and wavelet acoustic analysis techniques are used to detect different modes of cavitation with high sensitivity which are then tested for correlation to nerve responses. In the present case, direct ultrasound stimulation of peripheral axonal tissue is found to require either stable or inertial cavitation. The lowest intensity at which stimulation is observed is 25 W/cm2, similar to previous neuromodulatory thresholds found in peripheral nerves. This study therefore represents a significant advance in our understanding of the mechanisms behind the ultrasound neurostimulation phenomenon

    A qualitative study of patients’ feedback about Outpatient Parenteral Antimicrobial Therapy (OPAT) services in Northern England: implications for service improvement

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    Objective Outpatient parenteral antimicrobial therapy (OPAT) provides opportunities for improved cost savings, but in the UK, implementation is patchy and a variety of service models are in use. The slow uptake in the UK and Europe is due to a number of clinical, financial and logistical issues, including concern about patient safety. The measurement of patient experience data is commonly used to inform commissioning decisions, but these focus on functional aspects of services and fail to examine the relational aspects of care. This qualitative study examines patients’ experiences of OPAT. Design In-depth, semistructured interviews. Setting Purposive sample of OPAT patients recruited from four acute National Health Service (NHS) Trusts in Northern England. These NHS Trusts between them represented both well-established and recently set-up services running nurse at home, hospital outpatient and/or selfadministration models. Participants We undertook 28 semistructured interviews and one focus group (n=4). Results Despite good patient outcomes, experiences were coloured by patients' personal situation and material circumstances. Many found looking after themselves at home more difficult than they expected, while others continued to work despite their infection. Expensive car parking, late running services and the inconvenience of waiting in for the nurse to arrive frustrated patients, while efficient services, staffed by nurses with the specialist skills needed to manage intravenous treatment had the opposite effect. Many patients felt a local, general practitioner or community health centre based service would resolve many of the practical difficulties that made OPAT inconvenient. Patients could find OPAT anxiety provoking but this could be ameliorated by staff taking the time to reassure patients and provide tailored information. Conclusion Services configurations must accommodate the diversity of the local population. Poor communication can leave patients lacking the confidence needed to be a competent collaborator in their own care and affect their perceptions of the service

    Using PETTLEP imagery to improve music performance: A review

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    Imagery is commonly used by both athletes and musicians as an additional training aid to enhance performance. Although considerable research attention has been paid to this psychological intervention technique in sporting settings, studies investigating the beneficial effects of imagery on musical performance are less common. Imagery research that has been conducted in musical settings has tended to show that imagery is beneficial in improving performance, although few guidelines exist in the music literature regarding how musicians could use imagery to improve their performance. In this article, we review the research which has investigated the use of imagery as a performance enhancing technique in musical settings to date. We then outline a model for designing imagery interventions (known as the PETTLEP model) which has produced beneficial performance effects when implemented in sporting settings, and discuss how it could be used by musicians to enhance performance

    Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

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    OBJECTIVE: To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. METHODS: Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. RESULTS: Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. CONCLUSIONS: Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. KEY POINTS: • High patient satisfaction at CTC is deliverable across a national screening programme. • Patients who cannot tolerate screening colonoscopy are likely to find CTC acceptable. • CTC is extremely safe; complications are rare and almost never serious. • Patients may require more detailed information regarding the expected discomfort of CTC

    Climatic Changes, Water Systems, and Adaptation Challenges in Shawi Communities in the Peruvian Amazon

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    Climate change impacts on water systems have consequences for Indigenous communities. We documented climatic changes on water systems observed by Indigenous Shawi and resultant impacts on health and livelihoods, and explored adaptation options and challenges in partnership with two Indigenous Shawi communities in the Peruvian Amazon. Qualitative data were collected via PhotoVoice, interviews, focus group discussions, and transect walks, and analyzed using a constant comparative method and thematic analysis. Quantitative data were collected via a household survey and analyzed descriptively. Households observed seasonal weather changes over time (n = 50; 78%), which had already impacted their family and community (n = 43; 86%), such as more intense rainfall resulting in flooding (n = 29; 58%). Interviewees also described deforestation impacts on the nearby river, which were exacerbated by climate-related changes, including increased water temperatures (warmer weather, exacerbated by fewer trees for shading) and increased erosion and turbidity (increased rainfall, exacerbated by riverbank instability due to deforestation). No households reported community-level response plans for extreme weather events, and most did not expect government assistance when such events occurred. This study documents how Indigenous peoples are experiencing climatic impacts on water systems, and highlights how non-climatic drivers, such as deforestation, exacerbate climate change impacts on water systems and community livelihoods in the Peruvian Amazon

    Histological 3D reconstruction and in vivo lineage tracing of the human endometrium

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    Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higher‐order primates. The current consensus postulates endometrial glands to have a single‐tubular architecture, where multi‐potential stem cells reside in the blind‐ending glandular‐bases. Utilising fixed samples from patients, we have studied the three‐dimensional (3D) micro‐architecture of the human endometrium. We demonstrate that some non‐branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stem‐cell population resides in the basalis glands. These novel findings provide insight into the efficient and scar‐less regenerative potential of the human endometrium
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