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Stereolithography for tailoring the dynamics of flexural ultrasonic transducers
Get PDFThe flexural ultrasonic transducer (FUT) is a sensor primarily composed of a circular metallic plate, to which a piezoelectric ceramic disc is bonded. The vibrations generated from the piezoelectric ceramic stimulate vibration modes in the plate, thereby generating ultrasound waves. FUTs are typically utilised for industrial and proximity measurement, and are narrowband in their nature. This means that driving even marginally off-resonance can significantly reduce their amplitude performance. In this study, additive manufacturing is explored to broaden the bandwidth of the FUT beyond what is possible using metallic variants. Here, stereolithography apparatus (SLA) printing is used to design FUT plates, thereby demonstrating how operational bandwidth can be tailored. Through using SLA resins, the achievable resonance frequencies are lower than those for metallic FUTs due to the significantly lower levels of Young’s modulus. Here, SLA resin based FUTs are also demonstrated with comparable resonance frequencies to commercial metallic FUTs, showing their potential for industrial applications. There are opportunities for tailoring the dynamics of the transducer via the use of nonmetallic materials which will enable for rapid and low cost FUT manufacture. Using finite element analysis, electrical impedance measurement, laser Doppler vibrometry, and acoustic microphone measurement, this study shows how low-cost photopolymer resin-based air coupled FUTs can be designed and fabricated, with enhanced bandwidth compared to metallic equivalents, in addition to wider beamwidth radiation patterns
‘6.5 sounds a bit better than 6.0?’: A case for embedding language assessment literacy in university teaching staff professional development
Get PDFLanguage test scores are often used as one of the entry requirements for university admission, but perceptions of university teaching staff about students’ language proficiency (including those based on test scores) can have far-reaching impact beyond admissions selection – in teaching, learning and assessment. This paper explores what aspects of test score interpretation and use might be useful to embed in professional development for university teaching staff, an emergent theme from a multiple case study involving interviews with admissions personnel in six university admissions contexts. The analysis identified the need to further develop knowledge about the meaning of language test scores and the limits of inferences based on such scores, as well as an appreciation of the complex relationship between language proficiency and academic literacy. We conclude by envisioning an agenda for research and engagement embedding language assessment literacy in professional development programmes for university teaching staff
Remotely delivered weight management for people with long COVID and overweight: the randomized wait-list-controlled ReDIRECT trial
Get PDFLong COVID (LC) is a complex multisymptom condition with no known disease-modifying treatments. This wait-list-controlled open-label trial tested whether a remotely delivered structured weight management program could improve respective LC symptoms in people living with overweight. Adults with LC (symptoms >12 weeks) and body mass index >27 kg m−2 (>25 kg m−2 for South Asians) were randomized (n = 234, 1:1) to control (n = 116, usual care) or the remotely delivered structured weight management (n = 118, total diet replacement (850 kcal per day) for 12 weeks, followed by food reintroduction and weight loss maintenance support) via minimization and randomization (80:20) to balance dominant LC symptom, sex, age, ethnicity and postcode-based index of multiple deprivation between groups. The control group received the intervention after 6 months. Participants selected the dominant LC symptom they would most like to improve (fatigue, breathlessness, pain, anxiety/depression or other) as the prespecified respective primary outcome. Individual symptoms were assessed using validated questionnaires and a visual analog scale for those without prespecified scales. At 6 months, the primary outcome improved in the intervention group (change −1.16 (s.d. 1.42), n = 97 analyzed) compared with the control group (change −0.83 (s.d. 1.14), n = 117 analyzed) with a treatment effect of −0.34 (95% confidence interval −0.67 to −0.01), with no excess of serious adverse events. International Standard Randomised Controlled Trial Number Registry registration: ISRCTN12595520
Effect of exercise on kidney-relevant biomarkers in the general population: a systematic review and meta-analysis
Get PDFObjective: Physical activity (PA) has been generally recognised as beneficial for health. The effect of a change in PA on kidney biomarkers in healthy individuals without kidney disease remains unclear. This manuscript synthesised the evidence of the association of changes in PA with kidney biomarkers in the general population free from kidney disease.
Design: Systematic review and meta-analysis.
Data sources: Embase, PubMed, MEDLINE and Web of Science databases were searched from inception to 12 March 2023.
Eligibility criteria for selecting studies: Studies of longitudinal or interventional design were selected initially. The following studies were excluded: (1) case-control studies, (2) studies where PA was measured at a single time point, (3) populations with known kidney disease, (4) studies evaluating the impact of a single episode/event of PA and (5) non-English language studies.
Data extraction and synthesis: Two independent reviewers extracted data from a pre-designed table and assessed the risk of bias using the Cochrane Risk of Bias tool. Data were pooled using a random-effects model. Hedge’s g was used to synthesise effect sizes and obtain an overall estimate. Heterogeneity between studies was measured using I2. Funnel plots and Egger’s test were performed to evaluate the risk of biased results.
Results: 16 interventional studies with randomised or non-randomised designs involving 500 participants were identified. The median follow-up was 84 days. 10 studies were at high risk of bias. Studies with low quality were published prior to the year 2000. Changes in PA were found only to have a positive association with serum creatinine (SCr) (Hedge’s g=0.69; 95% CI 0.13, 1.24; I2=81.37%) and not with plasma renin activity (PRA), urea, or urine albumin-to-creatinine ratio (UACR). The positive association was only observed in people with obesity and those who exercised for more than 84 days.
Conclusions: Higher levels of PA are associated with increased SCr levels in healthy people. It remains unclear if this association is related to impaired kidney function or gain in muscle mass, as data on other kidney biomarkers did not support a certain link.
PROSPERO registration number: This review has been registered on PROSPERO (CRD42023407820)
Electrostatic instability of non-spherical dust in sub-stellar clouds
No full textCharged dust clouds play an important role in the evolution of sub-stellar atmospheres through lightning events. The consequent plasma activation presents an alternative source of disequilibrium chemistry, potentially triggering a set of chemical reactions otherwise energetically unavailable. The aim of this paper is to address the problem of the electrostatic stability of charged spheroidal dust grains in sub-stellar clouds and its impact on inter-grain electrostatic discharges, the available area for atmospheric gas-phase surface chemistry, the particle eccentricity distribution function and observed polarization signatures. This paper has derived the criterion for the allowed values of dust eccentricity that are electrostatically stable as a function of grain size a ∈ [0.2, 1.8] μm, floating potential φf ∈ [1, 10] V and tensile strength Σs = 103 Pa. As a consequence of electrostatic instability we also calculate the expected electric field enhancement at the spheroidal poles, the increased surface area of a dust grain, the truncation of the particle eccentricity distribution function and the resultant degree of polarization. Dust grains with an eccentricity below a critical value will be stable to electrostatic instability; whereas, grains with an eccentricity above a critical value will be unstable. For example, for a 1 μm charged dust grain with surface potential of 1 V, the maximum allowable eccentricity is 0.987. As a consequence, electric field strength enhancement at the pole is limited to a factor of 3.5; the surface area for surface chemistry and the synthesis of chemical products is increased by a factor of 1.45; and the degree of polarization is reduced by a factor of 0.65. The results presented here are applicable not only to spheroidal dust grains but any non-spherical dust grains where non-uniform surface electric fields or inhomogeneous tensile strengths could be susceptible to electrostatic instability. In this context electrostatic erosion presents a mechanism that may produce bumpy, irregularly shaped or porous grains
Clinical characteristics and outcomes of patients with heart failure with preserved ejection fraction and with reduced ejection fraction according to the prognostic nutritional index: findings from PARADIGM‐HF and PARAGON‐HF
Get PDFBackground:
The importance of nutritional status is underappreciated in patients with heart failure (HF). This study aimed to describe the range of the prognostic nutrition index (PNI), and the clinical characteristics and outcomes according to PNI, in patients with HF with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF). The primary outcome was the composite of HF hospitalization or cardiovascular death.
Methods and Results:
Individual patient data from the PARAGON‐HF (Prospective Comparison of ARNI [Angiotensin Receptor–Neprilysin Inhibitor] with ARB [Angiotensin Receptor Blocker] Global Outcomes in HFpEF) and PARADIGM‐HF (Prospective Comparison of ARNI With ACEI [Angiotensin‐Converting Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in HF) trials were used to examine patient characteristics and outcomes according to quartiles of PNI. Cox regression was used to analyze clinical outcomes, and multivariable fractional polynomial interaction analysis to examine the effects of sacubitril‐valsartan, according to PNI. Patients with lower PNI (poorer nutrition) were older, frailer, and had more comorbidities and worse HF status, with greater congestion. Patients with lower PNI had biomarker abnormalities indicating inflammation, bone marrow suppression, and increased collagen turnover, among other physiologic perturbations. Lower PNI was associated with worse outcomes; that is, the rate of the primary end point among patients in the first quartile was 11.31 (10.20–12.54) compared with 7.09 (6.17–8.14) per 100 person‐years in the fourth quartile. These associations persisted after adjustment for other prognostic variables. PNI did not modify the effects of sacubitril‐valsartan in HFrEF although sacubitril/valsartan seemed to have a greater benefit in patients with HFpEF with a higher PNI.
Conclusions:
Nutritional status, assessed using PNI, is an independent predictor of poor outcomes in HF. Evaluation of nutritional status in clinical practice, the causes of undernutrition, and whether undernutrition should be a therapeutic target, are all worthy of further investigation in HF
Geo-computation techniques for identifying spatio-temporal patterns of reported oil spills along crude oil pipeline networks
Get PDFThe Niger Delta region of Nigeria is a major oil-producing area which experiences frequent oil spills that severely impacts the local environment and communities. Effective environmental monitoring and management remain inadequate in this area due to negligence, slow response times following oil spills, and difficulties regarding access and safety. This study investigates the spatiotemporal patterns of oil spills along the pipeline network from 2013 to 2021 using geo-computation techniques. Utilising the spNetwork package in R, Network Kernel Density Estimates (NKDE) and its temporal extension, Temporal Network Kernel Density Estimates (TNKDE) were carried out. Pipeline data were transformed into 500-metre lixels (linear pixels) to compute network distances and generate density estimates. NKDE identified oil spill hotspots, while TNKDE illustrated the temporal transitions of spills. These methods surpass traditional approaches (e.g. KDE, cluster analysis, point pattern analysis) by incorporating network constraints and uncovering critical spatial–temporal patterns. The findings offer valuable insights for targeted interventions to reduce future spills and mitigate past impacts
What constitutes a high-quality guideline: exploring consumers’ views
Get PDFIntroduction:
Clinical guidelines are a cornerstone of evidence-based medicine. Little is known about clinicians' knowledge of guideline development and how they perceive guideline quality.
Methods:
A survey protocol was designed according to the CHERRIES (improving the quality of web surveys: the Checklist for Reporting Results of Internet E-Surveys) checklist. The survey explored three main aspects: high-quality markers of guidelines, knowledge of guideline development, and areas for improvement. The survey was conducted by contacting UEG and affiliated societies by email and via social media. All valid answers to each question were counted.
Results:
A total of 585 participants responded during the 3-month period. Some 65.8% were aged between 30 and 60 years, and 75.4% were doctors. The most important perceived quality indicators within a guideline were ‘clear and actionable recommendations (97%)’, followed by ‘based on systematic literature review’ (96%), and ‘transparent methodology’ (90%). 230 (39.3%) respondents were previously involved in clinical guideline development. However, the experience of working with a methodologist (18.8%) and using well-established guideline checklists (AGREE-II [21.0%]), RIGHT (Reporting Items for Practice guidelines in HealThcare) (9.9%) were limited. Just under half of the responders (289, 49.4%) were familiar with the GRADE methodology. Apps (78.5%), webinars (73.8%), and short videos (68.2%) were popular tools to access clinical guidelines. Over 90% of responders stated that the reputation of the journal (92%) and the name of the society involved in guideline development (91%) were important. Two-thirds of the responders preferred to see abridged versions of guidelines and 69.2% preferred freely accessible or open access guidelines.
Conclusion:
Consumers are keen to read clear and actionable guidelines that are developed transparently. There is a gap in guideline development knowledge. Initiatives by medical journals and professional societies are important to ensure the development of accessible and robust clinical guidelines
A new era of inequality: profound changes to mortality in England, Scotland, and 10 major British cities
Get PDFDeeply concerning changes to UK health trends have been noted since the early 2010s, including a widening of mortality inequalities. Given the importance of urban areas to national health outcomes, we sought to address gaps in the evidence by examining trends in intra-city mortality inequalities across Britain, including assessing the impact of the peak COVID-19 pandemic period. Age-standardized mortality rates were calculated (for England, Scotland, and 10 major UK cities) by age (all ages, 0–64 years), sex, year (1981–2020), and country-specific and city-specific area-based quintiles of socio-economic deprivation. Trends in absolute and relative inequalities in mortality by country and city were analysed by means of the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII), respectively. Profound changes to mortality trends and inequalities were observed across both nations and all cities in the decade up to 2020, including increases in death rates among the 20% most deprived populations of almost every city. For deaths at all ages, this was particularly evident in Leeds, Liverpool, Edinburgh, Dundee, and Glasgow. For 0–64 years, Scottish cities stood out. With few exceptions, both absolute and relative inequalities increased in the same time period. COVID-19 further increased death rates and inequalities. The analyses provide a hugely concerning picture of worsening mortality and widening inequalities across England and Scotland. When viewed in the context of the evidence for the impact of UK government austerity policies on population health, they represent a wake-up call for both current and future UK governments
Data sources:
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