Below are recent articles (co-)authored by Brunel academic staff. Please click the title of the article to access the full-text.
Macroprolactin over time: Is there any point in rechecking it in people with a persistently elevated serum prolactin?
Livingston, M. et al
Clinical Endocrinology, Vol 100, No 5, p. 450-458 (May 2024)
Objective and Design: Macroprolactinemia may influence the interpretation of serum prolactin levels-a recognised phenomenon since 1981. The degree of macroprolactinaemia over time is less well described. We determined how macroprolactin status (based on polyethylene glycol (PEG) precipitation) varied by analysing serial measurements in hyperprolactinaemic individuals over a period of 9 years. Patients and Measurements: Results from 1810 individuals were included. All serum total prolactin results (measured using Roche Cobas 8000 analyser) were extracted from the laboratory information system for the period 1 January 2012 to 1 April 2021, along with relevant patient demographic/test data. Samples with a macroprolactin screening test performed (on samples with prolactin > 700 miu/L) were included in the main analysis. Results: During the study period, 2782 macroprolactin checks were performed (12.5% of all prolactin tests) in 1810 individuals (599 males/2183 females, median-age: 35, interquartile range: 25-47, range: 16-93 years). Multiple macroprolactin checks were carried out on 465 patients (1437 measurements) with 94 patients (141 measurements) screening positive (<60% recovery). Only 19 patients (18 female) had at least one result above and one below the 60% screening cut-off, with 10 of these patients having results close to the 60% cut-off; in 9 patients, results were clearly different between repeat samples. In seven cases, the adjusted monomeric prolactin showed a potentially clinically significant difference. Conclusions: In this study, only 19/465 patients appeared to change macroprolactin status based on a 60% PEG recovery cut-off. The majority of these 19 patients were on antipsychotic/antidepressant medication(s) or had a prolactinoma; in only 7 did monomeric prolactin change significantly. This suggests that once macroprolactin status has been determined, clinical decision making is rarely affected by repeating it.
Defect Detection Algorithm for Battery Cell Casings Based on Dual-Coordinate Attention and Small Object Loss Feedback
Li, T. J. et al
Processes, Vol 12, No 3, Art No. 601 (Mar 2024)
To address the issue of low accuracy in detecting defects of battery cell casings with low space ratio and small object characteristics, the low space ratio feature and small object feature are studied, and an object detection algorithm based on dual-coordinate attention and small object loss feedback is proposed. Firstly, the EfficientNet-B1 backbone network is employed for feature extraction. Secondly, a dual-coordinate attention module is introduced to preserve more positional information through dual branches and embed the positional information into channel attention for precise localization of the low space ratio features. Finally, a small object loss feedback module is incorporated after the bidirectional feature pyramid network (BiFPN) for feature fusion, balancing the contribution of small object loss to the overall loss. Experimental comparisons on a battery cell casing dataset demonstrate that the proposed algorithm outperforms the EfficientDet-D1 object detection algorithm, with an average precision improvement of 4.23%. Specifically, for scratches with low space ratio features, the improvement is 13.21%; for wrinkles with low space ratio features, the improvement is 9.35%; and for holes with small object features, the improvement is 3.81%. Moreover, the detection time of 47.6 ms meets the requirements of practical production.
Investigation on the modeling and simulation of hydrodynamics in asymmetric conduction laser micro-welding of austenitic stainless steel and its process optimization
de la Hoz, J. L. V. et al
Procs. of the IMechE Pt B - J. of Engnng Manufacture, Early Access (Mar 2024)
Laser micro-welding is a joining technology utilized across various high-value industries, like medical, automotive, e-mobility, and aerospace. A trial-and-error process to identify welding parameters does not necessarily lead to optimized quality levels. Furthermore, offline non-destructive examination methods often launched to verify welding quality may inadvertently trigger excessive costs and time delays, ultimately failing to guarantee defect-free welds. In response to these challenges, this article introduces an advanced multiscale model designed to unravel the intricate dynamics of hydrodynamics and the overarching physics within laser micro-welding melting pools. Developed using the COMSOL software package, the model adeptly demonstrates how surface tension gradients shape the geometry of welds, thus influencing their quality. This knowledge allows the mapping of welding defects. One of the novelties of the article is to introduce geometric dissimilar welding conditions by simulating an asymmetric edge joint. It shows a study on a new, unstudied way to laser weld with many applications in the field. The model further establishes its utility in design experiments to determine parameter, tolerance, and system design. Moreover, the insights garnered from understanding and controlling these drivers have far-reaching implications for the advancement of subsequent methodological research and the development of in-situ quality control practices by characterizing the welding defects. Finally, the results shows that the discouragingly high computational costs restrict its potential application to support a Digital Twin.
Testosterone therapy reduces insulin resistance in men with adult-onset testosterone deficiency and metabolic syndrome. Results from the Moscow Study, a randomized controlled trial with an open-label phase
Tishova, Y. et al
Diabetes Obesity & Metabolism, [Early Access], (Mar 2024)
Aims: To describe changes in homeostasis model assessment of insulin resistance index (HOMA-IR) following testosterone therapy in men with hypogonadism and metabolic syndrome (MetS).Materials and Methods. A randomized, placebo-controlled, double-blind randomized controlled trial (RCT) comprising 184 men with MetS and hypogonadism (testosterone undecanoate [TU]: 113 men, placebo: 71 men) was conducted. This was followed by an open-label phase in which all men were given TU. We focused on men who were not receiving antiglycaemic agents (TU: 81 men; placebo: 54 men) as these could affect HOMA-IR. Inter-group comparison of HOMA-IR was restricted to the RCT (30 weeks), whilst intra-group comparison was carried out on men provided TU during the RCT and open-label phases (study cohort) and men given placebo during the RCT and then switched to TU during the open-label phase (confirmatory cohort). Regression analysis was performed to identify factors associated with change in HOMA-IR ( increment HOMA-IR). Results: The median HOMA-IR was significantly reduced at almost every time point (after 18 weeks) compared to baseline in men receiving TU in both the study and confirmatory cohorts. There was a significant decrease in median values of fasting glucose (30 weeks: -2.1%; 138 weeks: -4.9%) and insulin (30 weeks: -10.5%; 138 weeks: -35.5%) after TU treatment. Placebo was not associated with significant increment HOMA-IR. The only consistent predictor of HOMA-IR decrease following TU treatment was baseline HOMA-IR (r2 >= 0.64). Conclusions: Baseline HOMA-IR predicted Delta HOMA-IR, with a greater percentage change in insulin than in fasting glucose. In men with MetS/type 2 diabetes (T2DM) not on antiglycaemic therapy, improvements in HOMA-IR may be greater than suggested by change in fasting glucose. Our results suggest that hypogonadism screening be included in the management of men with MetS/T2DM.
Complete revascularization is associated with higher mortality in patients with ST-elevation myocardial infarction, multi-vessel disease and shock defined by hyperlactataemia: results from the Harefield Shock Registry incorporating explainable machine learning
Tindale, A. et al
European Heart Journal-Acute Cardiovascular Care, Vol 12, No 9, p.615-623 (Jun 2023)
Aims Revascularization strategy for patients with ST-elevation myocardial infarction (STEMI) and multi-vessel disease varies according to the patient's cardiogenic shock status, but assessing shock acutely can be difficult. This article examines the link between cardiogenic shock defined solely by a lactate of >= 2 mmol/L and mortality from complete vs. culprit-only revascularization in this cohort. Methods and results Patients presenting with STEMI, multi-vessel disease without severe left main stem stenosis and a lactate >= 2 mmol/L between 2011 and 2021 were included. The primary endpoint was mortality at 30 days by revascularization strategy for shocked patients. Secondary endpoints were mortality at 1 year and over a median follow-up of 30 months. Four hundred and eight patients presented in shock. Mortality in the shock cohort was 27.5% at 30 days. Complete revascularization (CR) was associated with higher mortality at 30 days [odds ratio (OR) 2.1 (1.02-4.2), P = 0.043], 1 year [OR 2.4 (1.2-4.9), P = 0.01], and over 30 months follow-up [hazard ratio (HR) 2.2 (1.4-3.4), P < 0.001] compared with culprit lesion-only percutaneous coronary intervention (CLOP). Mortality was again higher in the CR group after propensity matching (P = 0.018) and inverse probability treatment weighting [HR 2.0 (1.3-3.0), P = 0.001]. Furthermore, explainable machine learning demonstrated that CR was behind only blood gas parameters and creatinine levels in importance for predicting 30-day mortality. Conclusion In patients presenting with STEMI and multi-vessel disease in shock defined solely by a lactate of >= 2 mmol/L, CR is associated with higher mortality than CLOP.