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Complex Self-Organization in n-Alkylammonium Sulfobetaine Zwitterions with High Thermal Stabilities and High Expansion Coefficients
Get PDFSulfobetaine zwitterions made from n-alkyl dimethylamines and butanesultone yield a series of n-alkylammonium sulfobetaine zwitterions with complex self-organization behavior. The compounds are thermally quite stable and the length of the alkyl chain directly affects all phase transition temperatures of the compounds: the longer the alkyl chain, the higher the transition temperature. All compounds exhibit lamellar order and the different phases are characterized by a lower temperature orthorhombic and a higher temperature hexagonal in-plane order. The phase transition from the orthorhombic to the hexagonal phase is always associated with an increase of the long period. The phase transition is also associated with a rather high thermal expansion coefficient
Flow Separation Control of a Vertical Stabiliser Using a Rudder-Mounted Slat
Get PDFA joint study utilising experimental and numerical methods was carried out to investigate the aerodynamic effect of a rudder-mounted slat on a vertical stabiliser. The wind tunnel test results showed that the side force coefficient was increased more than 3% with a negligible increase in drag when the rudder deflection angle was set to δ = 30°. Large eddy simulation (LES) results suggested that the rudder-mounted slat can increase the circulation around the vertical stabiliser, showing that the flow from the upstream recirculating regions was drawn towards the rudder surface. Associated changes in the turbulent flow field, including the mean and turbulent flow field and the vortical structure are also presented to understand the flow control mechanism by the rudder-mounted slat
Infinitesimal 2-braidings from 2-shifted Poisson structures
Get PDFIt is shown that every 2-shifted Poisson structure on a finitely generated semi-free commutative differential graded algebra A defines a very explicit infinitesimal 2-braiding on the homotopy 2-category of the symmetric monoidal dg-category of finitely generated semi-free A-dg-modules. This provides a concrete realization, to first order in the deformation parameter ħ, of the abstract deformation quantization results in derived algebraic geometry due to Calaque, Pantev, Toën, Vaquié and Vezzosi. Of particular interest is the case when A is the Chevalley-Eilenberg algebra of a Lie N-algebra, where the braided monoidal deformations developed in this paper may be interpreted as candidates for representation categories of ‘higher quantum groups’
Enhancing Health Outcomes through Optimized Body Composition in Prehabilitation
Get PDFBackground: Prehabilitation, the process of optimizing a patient's physical and nutritional status before surgery, has gained increasing attention for its potential to improve outcomes by enhancing physiological reserves and functional capacity. While body composition may play a role in these outcomes, its specific contribution remains underexplored. This narrative review summarizes current evidence on the effects of prehabilitation on body composition, focusing on exercise, nutritional interventions, and multimodal approaches. Summary: Exercise, particularly a combination of aerobic and resistance training, has been shown to improve cardiorespiratory fitness, reduce fat mass, and enhance skeletal muscle and strength. Nutritional interventions, including increased protein intake, support skeletal muscle preservation, and recovery. A multimodal approach, integrating both exercise and nutrition, yields the most significant improvements in body composition, showing enhanced skeletal muscle, reduced fat mass, and better functional outcomes. However, the limited duration of prehabilitation and the time required for detectable changes in body composition often prevent consistent observations. Furthermore, variations in assessment techniques and protocols across studies confound definitive conclusions. Key Messages: Despite some promising results, further research is needed to standardize protocols and explore the effects of prehabilitation on body composition across diverse patient populations. Finally, further research is needed to investigate the impact of prehabilitation on measurable changes in body composition as this represents a critical gap in the field
Solitary bubbles rising in quiescent liquids: A critical assessment of experimental data and high-fidelity numerical simulations, and performance evaluation of selected prediction methods
Get PDFBubbles are ubiquitous in industrial applications and in the natural environment. The dynamics of solitary bubbles rising through quiescent liquids, in particular, underpins the physics of two-phase bubbly flows, which are commonplace in industrial, biological, and environmental flows. This review provides a critical assessment of experimental data and high-fidelity numerical simulations concerning the rise of solitary bubbles in quiescent liquids, and an evaluation of selected prediction methods for the rise velocity and the aspect ratio of the bubbles. The assessment of the experimental data is performed by way of a large and diversified bubble rise data bank collected from the literature (7192 data points from 58 literature studies), which is critically analyzed dedicating special attention to various aspects that have not been adequately addressed in previous investigations, including the methodologies employed to generate the bubbles, the techniques adopted to measure their size, shape, and rise velocity, the consequence of the liquid contamination on the bubble dynamics, wall-confinement effects, and the mass transfer between the bubble and the surrounding liquid. The assessment of the computational studies covers direct numerical simulations with interface capturing, interface tracking methods, and linear stability analyses, which are critically analyzed with specific focus on numerical methods, computational mesh, validation vs experimental data, and their main findings. The evaluation of the prediction methods is restricted to selected and widely quoted methodologies, three for the bubble rise velocity and four for the bubble aspect ratio, which have been proposed for final applications and whose performance is assessed against the measured data. The curated bubble rise data bank is provided in full and usable form. Research gaps and topics that necessitate further investigation are identified and discussed
Methodologies for network meta-analysis of randomised controlled trials in pain, anaesthesia, and perioperative medicine: a narrative review
Get PDFNetwork meta-analysis has emerged as a method for analysing clinical trials, with a large increase in the number of publications over the past decade. Network meta-analysis offers advantages over traditional pairwise meta-analysis, including increased power, the ability to compare treatments not compared in the original trials, and the ability to rank treatments. However, network meta-analyses are inherently more complex than pairwise meta-analyses, requiring additional statistical expertise and assumptions. Many factors can affect the certainty of evidence from pairwise meta-analysis and can often lead to unreliable results. Network meta-analysis is prone to all these issues, although it has the additional assumption of transitivity. Here we review network meta-analyses, problems with their conduct and reporting, and methodological strategies that can be used by those conducting reviews to help improve the reliability of their findings. We provide evidence that violation of the assumption of transitivity is relatively common and inadequately considered in published network meta-analyses. We explain key concepts with clinically relevant examples for those unfamiliar with network meta-analysis to facilitate their appraisal and application of their results to clinical practice
Opportunities and challenges to delivering a trial for depressive symptoms in primary care during the COVID-19 pandemic: insights from the Alpha-Stim-D randomised controlled trial
Get PDFBackground: Randomised controlled trials (RCTs) are widely regarded as the most powerful research design for evidence-based practice. However, recruiting to RCTs can be challenging resulting in heightened costs and delays in research completion and implementation. Enabling successful recruitment is crucial in mental health research. Despite the increase in the use of remote recruitment strategies and digital health interventions, there is limited evidence on methods to improve recruitment to remotely delivered mental health trials. The paper outlines practical examples and recommendations on how to successfully recruit participants to remotely delivered mental health trials. Methods: The Alpha Stim-D Trial was a multi-centre double-blind randomised controlled trial, for people aged 16years upwards, addressing depressive symptoms in primary care. Despite a 6-month delay in beginning recruitment due to the COVID-19 pandemic, the trial met the recruitment target within the timeframe and achieved high retention rates. Several strategies were implemented to improve recruitment; some of these were adapted in response to the COVID-19 pandemic. This included adapting the original in-person recruitment strategies. Subsequently, systematic recruitment using postal invitations from criteria-specific search of the sites’ electronic health records was added to opportunistic recruitment to increase referrals in response to sub-target recruitment whilst also reducing the burden on referring sites. Throughout the recruitment process, the research team collaborated with key stakeholders, such as primary care clinicians and the project’s Patient and Public Involvement and Engagement (PPI/E) representatives, who gave advice on recruitment strategies. Furthermore, the study researchers played a key role in communicating with participants and building rapport from study introduction to data collection. Conclusions: Our findings suggest that trial processes can influence recruitment; therefore, consideration and a regular review of the recruitment figures and strategies is important. Recruitment of participants can be maximised by utilising remote approaches, which reduce the burden and amount of time required by referring sites and allow the research team to reach more participants whilst providing participants and researchers with more flexibility. Effectively communicating and working collaboratively with key stakeholders throughout the trial process, as well as building rapport with participants, may also improve recruitment rates
The Cognitive and Neuroimaging for Neurodegenerative Disorders Study (CogNID): design and initial findings from real-world clinical practice
Get PDFIntroduction: Dementia presents with significant heterogeneity across age groups, particularly in early-onset cognitive decline (EOCD), which poses diagnostic and management challenges. The Cognitive and Neuroimaging for Neurodegenerative Disorders (CogNID) study aims to characterise clinical, cognitive, neuroimaging, and biomarker features across a diverse cohort of individuals with cognitive impairment, with a focus on diagnostic complexity, biomarker utility, and mortality.Methods: Out of 680 study participants within this prospective cohort enrolled from the real-world clinics within the National Health Service, who consented to take part in the study, we analysed data from 429. Individuals were recruited between December 2018 and November 2024 from the Memory Clinics, including the early-onset dementia service and associated services. Participants underwent structured cognitive assessments, neuroimaging (MRI/CT), and Cerebrospinal fluid (CSF) biomarker evaluation, where available. Diagnoses were made by multidisciplinary consensus. Group comparisons were conducted between early-onset (EOCD, <65 years) and late-onset cognitive decline (LOCD, ≥65 years).Results: Of the 429 participants, 349 (81.4%) had EOCD and 80 (18.6%) had LOCD. The mean age was 60.05 years, with no significant difference in sex or ethnicity across groups. Depression and anxiety were common (29.6%), as were cardiovascular risk factors. Lumbar punctures were more frequently performed in EOCD (p = 0.03), with 36.4% of tested participants demonstrating biomarker profiles consistent with Alzheimer’s disease (A+T+). Functional cognitive disorder (FCD) was more common in EOCD (22.3% vs. 5.0%, p < 0.001). Subgroup analysis revealed significantly lower ACE-III scores and higher pathological CSF findings in Alzheimer’s disease versus FCD. Mortality was higher in the LOCD group (11.3% vs. 4.6%, p = 0.03).Conclusion: The CogNID study highlights the clinical and diagnostic heterogeneity of individuals with cognitive impairment, particularly in younger adults. Incorporating neuroimaging and CSF biomarkers into routine clinical pathways enhances diagnostic precision and reveals distinct phenotypic profiles between EOCD and LOCD. These findings underscore the need for harmonised diagnostic protocols, broader biomarker accessibility, and inclusive recruitment strategies in dementia research and clinical services
Leading professional learning communities in China: the role of Teaching Research Group heads in two primary schools in Shanghai
No full textProfessional learning communities (PLCs) are recognized for their potential to enhance teaching and learning. While existing research has examined the leadership and sustainability of PLCs at the whole-school level, the role of teacher leaders in maintaining and developing PLCs remains underexplored. This study employs a comparative qualitative case study of two primary schools in Shanghai to investigate how Teaching Research Group (TRG) heads sustain and promote teacher learning within PLCs. The findings show that TRG heads play a crucial role in cultivating a collaborative culture, facilitating knowledge co-construction, and supporting both collective and individual teacher learning. By navigating the tension between bureaucracy and autonomy, their leadership strategies shape PLCs into enriched or perhaps impoverished communities. To foster sustainable and effective PLCs, TRG heads should be granted greater autonomy, teacher leadership should be developed, and teachers’ sense of ownership in PLCs should be strengthened
A novel fault detection and diagnostic Petri net methodology for dynamic systems
Get PDFFaults can have significant, negative impacts on the operation and performance of simple and complex dynamic systems. Based on the integration of Bayesian network diagnostic features with Petri net formalism, the existing Bayesian-supported Petri net tool has demonstrated the flexibility of using the Petri net approach for diagnosing failure scenario of a dynamic system. However, studies on using the proposed hybrid Petri net approach for condition monitoring and early detection and diagnosis of single and multiple failures in a dynamic system with feedback control loops are yet to be investigated. Thus, this paper presents a methodology to address this research gap using the operation of a water tank level control system as a case study. The method combines the constructed Generalised Stochastic Petri Net (GSPN) model of the system operation with its corresponding fault diagnostic Petri net model, created using the proposed modified Bayesian Stochastic Petri Net (mBSPN) formalism. The GSPN model establishes the causal relationships between the system’s components and/or subsystems. It further identifies deviations in the sensor measurements of the observable process variables characterising the system operation. The information provided by the sensors in the system model are then inputted into the mBSPN model to diagnose the root cause of the observed deviations. The obtained results demonstrated the capability of using the proposed integrated Petri net methodology for system condition monitoring, early fault detection and diagnosis of single and multiple failures in a dynamic system with feedback control loops
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