Showing papers by "University of Aberdeen published in 2022"

On the climate impacts of blue hydrogen production

Abstract: Natural gas based hydrogen production with carbon capture and storage is referred to as blue hydrogen. If substantial amounts of CO2 from natural gas reforming are captured and permanently stored, such hydrogen could be a low-carbon energy carrier. However, recent research raises questions about the effective climate impacts of blue hydrogen from a life cycle perspective. Our analysis sheds light on the relevant issues and provides a balanced perspective on the impacts on climate change associated with blue hydrogen. We show that such impacts may indeed vary over large ranges and depend on only a few key parameters: the methane emission rate of the natural gas supply chain, the CO2 removal rate at the hydrogen production plant, and the global warming metric applied. State-of-the-art reforming with high CO2 capture rates combined with natural gas supply featuring low methane emissions does indeed allow for substantial reduction of greenhouse gas emissions compared to both conventional natural gas reforming and direct combustion of natural gas. Under such conditions, blue hydrogen is compatible with low-carbon economies and exhibits climate change impacts at the upper end of the range of those caused by hydrogen production from renewable-based electricity. However, neither current blue nor green hydrogen production pathways render fully “net-zero” hydrogen without additional CO2 removal.

COSMOS-Europe: a European network of cosmic-ray neutron soil moisture sensors

Abstract: Abstract. Climate change increases the occurrence and severity of droughts due to increasing temperatures, altered circulation patterns, and reduced snow occurrence. While Europe has suffered from drought events in the last decade unlike ever seen since the beginning of weather recordings, harmonized long-term datasets across the continent are needed to monitor change and support predictions. Here we present soil moisture data from 66 cosmic-ray neutron sensors (CRNSs) in Europe (COSMOS-Europe for short) covering recent drought events. The CRNS sites are distributed across Europe and cover all major land use types and climate zones in Europe. The raw neutron count data from the CRNS stations were provided by 24 research institutions and processed using state-of-the-art methods. The harmonized processing included correction of the raw neutron counts and a harmonized methodology for the conversion into soil moisture based on available in situ information. In addition, the uncertainty estimate is provided with the dataset, information that is particularly useful for remote sensing and modeling applications. This paper presents the current spatiotemporal coverage of CRNS stations in Europe and describes the protocols for data processing from raw measurements to consistent soil moisture products. The data of the presented COSMOS-Europe network open up a manifold of potential applications for environmental research, such as remote sensing data validation, trend analysis, or model assimilation. The dataset could be of particular importance for the analysis of extreme climatic events at the continental scale. Due its timely relevance in the scope of climate change in the recent years, we demonstrate this potential application with a brief analysis on the spatiotemporal soil moisture variability. The dataset, entitled “Dataset of COSMOS-Europe: A European network of Cosmic-Ray Neutron Soil Moisture Sensors”, is shared via Forschungszentrum Jülich: https://doi.org/10.34731/x9s3-kr48 (Bogena and Ney, 2021).

Sex Differences in Behavior and Molecular Pathology in the 5XFAD Model

Abstract: The prevalence of Alzheimer's disease (AD) is greater in women compared to men, but the reasons for this remain unknown. This sex difference has been widely neglected in experimental studies using transgenic mouse models of AD.Here, we studied behavior and molecular pathology of 5-month-old 5XFAD mice, which express mutated human amyloid precursor protein and presenilin-1 on a C57BL/6J background, versus their wild-type littermate controls, to compare both sex- and genotype-dependent differences.A novel behavioral paradigm was utilized (OF-NO-SI), comprising activity measures (Open Field, OF) arena, followed by Novel Object exploration (NO) and Social Interaction (SI) of a sex-matched conspecific. Each segment consisted of two repeated trials to assess between-trial habituation. Subsequently, brain pathology (amyloid load, stress response and inflammation markers, synaptic integrity, trophic support) was assessed using qPCR and western blotting.Female 5XFAD mice had higher levels of human APP and amyloid-β and heightened inflammation versus males. These markers correlated with hyperactivity observed in both sexes, yet only female 5XFAD mice presented with subtle deficits in object and social exploration. Male animals had higher expression of stress markers and neurotrophic factors irrespective of genotype, this correlated with cognitive performance.The impact of sex on AD-relevant phenotypes is in line with human data and emphasizes the necessity of appropriate study design and reporting. Differential molecular profiles observed in male versus female mice offer insights into possible protective mechanisms, and hence treatment strategies.

Tolerating bad health research: the continuing scandal

Abstract: At the 2015 REWARD/EQUATOR conference on research waste, the late Doug Altman revealed that his only regret about his 1994 BMJ paper 'The scandal of poor medical research' was that he used the word 'poor' rather than 'bad'. But how much research is bad? And what would improve things?We focus on randomised trials and look at scale, participants and cost. We randomly selected up to two quantitative intervention reviews published by all clinical Cochrane Review Groups between May 2020 and April 2021. Data including the risk of bias, number of participants, intervention type and country were extracted for all trials included in selected reviews. High risk of bias trials was classed as bad. The cost of high risk of bias trials was estimated using published estimates of trial cost per participant. We identified 96 reviews authored by 546 reviewers from 49 clinical Cochrane Review Groups that included 1659 trials done in 84 countries. Of the 1640 trials providing risk of bias information, 1013 (62%) were high risk of bias (bad), 494 (30%) unclear and 133 (8%) low risk of bias. Bad trials were spread across all clinical areas and all countries. Well over 220,000 participants (or 56% of all participants) were in bad trials. The low estimate of the cost of bad trials was £726 million; our high estimate was over £8 billion. We have five recommendations: trials should be neither funded (1) nor given ethical approval (2) unless they have a statistician and methodologist; trialists should use a risk of bias tool at design (3); more statisticians and methodologists should be trained and supported (4); there should be more funding into applied methodology research and infrastructure (5).Most randomised trials are bad and most trial participants will be in one. The research community has tolerated this for decades. This has to stop: we need to put rigour and methodology where it belongs - at the centre of our science.

<scp>NLRP3</scp> inflammasome as a key molecular target underlying cognitive resilience in amyotrophic lateral sclerosis

Abstract: Up to 50% of amyotrophic lateral sclerosis patients present with cognitive deficits in addition to motor dysfunction, but the molecular mechanisms underlying diverse clinical and pathological presentations remain poorly understood. There is therefore an unmet need to identify molecular drivers of cognitive dysfunction to enable better therapeutic targeting and prognostication. To address this, we employed a non-biased approach to identify molecular targets using a deeply phenotyped, clinically stratified cohort of cognitively affected and unaffected brain regions from three brain regions of 13 amyotrophic lateral sclerosis patients with the same cognitive screening test performed during life. Using NanoString molecular barcoding as a sensitive mRNA sequencing technique on post-mortem tissue, we profiled a data-driven panel of 770 genes using the Neuropathology Panel, followed by region and cell type-specific validation using BaseScope in situ hybridisation and immunohistochemistry. We identified 50 significantly dysregulated genes that are distinct between cognitively affected and unaffected brain regions. Using BaseScope in situ hybridisation, we also demonstrate that macromolecular complex regulation, notably NLRP3 inflammasome modulation, is a potential, therapeutically targetable, pathological correlate of cognitive resilience in ALS. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Photodynamic versus white-light-guided resection of first-diagnosis non-muscle-invasive bladder cancer: PHOTO RCT

Abstract: Around 7500 people are diagnosed with non-muscle-invasive bladder cancer in the UK annually. Recurrence following transurethral resection of bladder tumour is common, and the intensive monitoring schedule required after initial treatment has associated costs for patients and the NHS. In photodynamic diagnosis, before transurethral resection of bladder tumour, a photosensitiser that is preferentially absorbed by tumour cells is instilled intravesically. Transurethral resection of bladder tumour is then conducted under blue light, causing the photosensitiser to fluoresce. Photodynamic diagnosis-guided transurethral resection of bladder tumour offers better diagnostic accuracy than standard white-light-guided transurethral resection of bladder tumour, potentially reducing the chance of subsequent recurrence.The objective was to assess the clinical effectiveness and cost-effectiveness of photodynamic diagnosis-guided transurethral resection of bladder tumour.This was a multicentre, pragmatic, open-label, parallel-group, non-masked, superiority randomised controlled trial. Allocation was by remote web-based service, using a 1 : 1 ratio and a minimisation algorithm balanced by centre and sex.The setting was 22 NHS hospitals.Patients aged ≥ 16 years with a suspected first diagnosis of high-risk non-muscle-invasive bladder cancer, no contraindications to photodynamic diagnosis and written informed consent were eligible.Photodynamic diagnosis-guided transurethral resection of bladder tumour and standard white-light cystoscopy transurethral resection of bladder tumour.The primary clinical outcome measure was the time to recurrence from the date of randomisation to the date of pathologically proven first recurrence (or intercurrent bladder cancer death). The primary health economic outcome was the incremental cost per quality-adjusted life-year gained at 3 years.We enrolled 538 participants from 22 UK hospitals between 11 November 2014 and 6 February 2018. Of these, 269 were allocated to photodynamic diagnosis and 269 were allocated to white light. A total of 112 participants were excluded from the analysis because of ineligibility (n = 5), lack of non-muscle-invasive bladder cancer diagnosis following transurethral resection of bladder tumour (n = 89) or early cystectomy (n = 18). In total, 209 photodynamic diagnosis and 217 white-light participants were included in the clinical end-point analysis population. All randomised participants were included in the cost-effectiveness analysis. Over a median follow-up period of 21 months for the photodynamic diagnosis group and 22 months for the white-light group, there were 86 recurrences (3-year recurrence-free survival rate 57.8%, 95% confidence interval 50.7% to 64.2%) in the photodynamic diagnosis group and 84 recurrences (3-year recurrence-free survival rate 61.6%, 95% confidence interval 54.7% to 67.8%) in the white-light group (hazard ratio 0.94, 95% confidence interval 0.69 to 1.28; p = 0.70). Adverse event frequency was low and similar in both groups [12 (5.7%) in the photodynamic diagnosis group vs. 12 (5.5%) in the white-light group]. At 3 years, the total cost was £12,881 for photodynamic diagnosis-guided transurethral resection of bladder tumour and £12,005 for white light. There was no evidence of differences in the use of health services or total cost at 3 years. At 3 years, the quality-adjusted life-years gain was 2.094 in the photodynamic diagnosis transurethral resection of bladder tumour group and 2.087 in the white light group. The probability that photodynamic diagnosis-guided transurethral resection of bladder tumour was cost-effective was never > 30% over the range of society's cost-effectiveness thresholds.Fewer patients than anticipated were correctly diagnosed with intermediate- to high-risk non-muscle-invasive bladder cancer before transurethral resection of bladder tumour and the ratio of intermediate- to high-risk non-muscle-invasive bladder cancer was higher than expected, reducing the number of observed recurrences and the statistical power.Photodynamic diagnosis-guided transurethral resection of bladder tumour did not reduce recurrences, nor was it likely to be cost-effective compared with white light at 3 years. Photodynamic diagnosis-guided transurethral resection of bladder tumour is not supported in the management of primary intermediate- to high-risk non-muscle-invasive bladder cancer.Further work should include the modelling of appropriate surveillance schedules and exploring predictive and prognostic biomarkers.This trial is registered as ISRCTN84013636.This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 40. See the NIHR Journals Library website for further project information.Around 7500 people are diagnosed with early-stage bladder cancer in the UK each year. Early bladder cancer is contained within the bladder and has not yet invaded the bladder’s muscle wall or spread elsewhere in the body. The cancer will return (recur) in around half of people after initial treatment and they have to attend hospital for regular check-ups, with costs to both them and the NHS. The first step in treating early bladder cancer is surgery to remove the tumour. This surgery is normally performed under white light. Photodynamic diagnosis is a new technique in which a liquid is put into the patient’s bladder before surgery and a blue light is used during the operation. This causes the bladder cancer to fluoresce so that it can be seen more easily by the surgeon. The Photodynamic versus white-light-guided resection of first diagnosis non-muscle-invasive bladder cancer ( PHOTO ) trial aimed to find out whether or not using photodynamic diagnosis at initial surgery would reduce how often the cancer recurred and whether or not this could reduce the cost of treating early bladder cancer. A total of 538 people with early bladder cancer who had a medium to high chance of their cancer returning after treatment were enrolled in the PHOTO trial. They were included in one of two treatment groups, at random: 269 had photodynamic surgery and 269 had standard white-light surgery. People in both groups were monitored regularly for any recurrences, with further treatment as appropriate. After 3 years, 4 out of 10 people in each group had a recurrence of their bladder cancer. We found no difference between the treatment groups in the number of people with recurrences. We found no evidence of a benefit to patients, and the total costs of photodynamic surgery were higher than those of standard white light. We therefore recommend that it is no longer used in the treatment of this group of patients.

Diabetic Retinopathy Predicts Risk of Alzheimer’s Disease: A Danish Registry-Based Nationwide Cohort Study

Abstract: Retinal neurodegeneration is evident in early diabetic retinopathy (DR) which may be associated with other neurodegenerative diseases like Alzheimer's disease (AD).To investigate diabetes and DR as a risk marker of present and incident AD.A register-based cohort study was performed. We included 134,327 persons with diabetes above 60 years of age, who had attended DR screening, and 651,936 age- and gender-matched persons without diabetes.At baseline, the prevalence of AD was 0.7% and 1.3% among patients with and without diabetes, respectively. In a multivariable regression model, patients with diabetes were less likely to have AD at baseline (adjusted OR 0.63, 95% CI 0.59-0.68). During follow-up, incident AD was registered for 1473 (0.35%) and 6,899 (0.34%) persons with and without diabetes, respectively. Compared to persons without diabetes, persons with diabetes and no DR had a lower risk to develop AD (adjusted HR 0.87, 95% CI 0.81-0.93), while persons with diabetes and DR had higher risk of AD (adjusted HR 1.24, 95% CI 1.08-1.43). When persons with diabetes and no DR were used as references, a higher risk of incident AD was observed in persons with DR (adjusted HR 1.34, 95% CI 1.18-1.53).Individuals with diabetes without DR were less likely to develop AD compared to persons without diabetes. However, individuals with DR had a 34% higher risk of incident AD, which raise the question whether screening for cognitive impairment should be done among individuals with DR.

Digital smartphone intervention to recognise and manage early warning signs in schizophrenia to prevent relapse: the EMPOWER feasibility cluster RCT

Abstract: Relapse is a major determinant of outcome for people with a diagnosis of schizophrenia. Early warning signs frequently precede relapse. A recent Cochrane Review found low-quality evidence to suggest a positive effect of early warning signs interventions on hospitalisation and relapse.How feasible is a study to investigate the clinical effectiveness and cost-effectiveness of a digital intervention to recognise and promptly manage early warning signs of relapse in schizophrenia with the aim of preventing relapse?A multicentre, two-arm, parallel-group cluster randomised controlled trial involving eight community mental health services, with 12-month follow-up.Glasgow, UK, and Melbourne, Australia.Service users were aged > 16 years and had a schizophrenia spectrum disorder with evidence of a relapse within the previous 2 years. Carers were eligible for inclusion if they were nominated by an eligible service user.The Early signs Monitoring to Prevent relapse in psychosis and prOmote Wellbeing, Engagement, and Recovery (EMPOWER) intervention was designed to enable participants to monitor changes in their well-being daily using a mobile phone, blended with peer support. Clinical triage of changes in well-being that were suggestive of early signs of relapse was enabled through an algorithm that triggered a check-in prompt that informed a relapse prevention pathway, if warranted.The main outcomes were feasibility of the trial and feasibility, acceptability and usability of the intervention, as well as safety and performance. Candidate co-primary outcomes were relapse and fear of relapse.We recruited 86 service users, of whom 73 were randomised (42 to EMPOWER and 31 to treatment as usual). Primary outcome data were collected for 84% of participants at 12 months. Feasibility data for people using the smartphone application (app) suggested that the app was easy to use and had a positive impact on motivations and intentions in relation to mental health. Actual app usage was high, with 91% of users who completed the baseline period meeting our a priori criterion of acceptable engagement (> 33%). The median time to discontinuation of > 33% app usage was 32 weeks (95% confidence interval 14 weeks to ∞). There were 8 out of 33 (24%) relapses in the EMPOWER arm and 13 out of 28 (46%) in the treatment-as-usual arm. Fewer participants in the EMPOWER arm had a relapse (relative risk 0.50, 95% confidence interval 0.26 to 0.98), and time to first relapse (hazard ratio 0.32, 95% confidence interval 0.14 to 0.74) was longer in the EMPOWER arm than in the treatment-as-usual group. At 12 months, EMPOWER participants were less fearful of having a relapse than those in the treatment-as-usual arm (mean difference -4.29, 95% confidence interval -7.29 to -1.28). EMPOWER was more costly and more effective, resulting in an incremental cost-effectiveness ratio of £3041. This incremental cost-effectiveness ratio would be considered cost-effective when using the National Institute for Health and Care Excellence threshold of £20,000 per quality-adjusted life-year gained.This was a feasibility study and the outcomes detected cannot be taken as evidence of efficacy or effectiveness.A trial of digital technology to monitor early warning signs that blended with peer support and clinical triage to detect and prevent relapse is feasible.A main trial with a sample size of 500 (assuming 90% power and 20% dropout) would detect a clinically meaningful reduction in relapse (relative risk 0.7) and improvement in other variables (effect sizes 0.3-0.4).This trial is registered as ISRCTN99559262.This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 27. See the NIHR Journals Library website for further project information. Funding in Australia was provided by the National Health and Medical Research Council (APP1095879).Relapse is a considerable problem for people with a diagnosis of schizophrenia. Relapse can be predicted by early warning signs that are unique to the person. They include withdrawal, fear and paranoia.Is it possible to investigate the effectiveness of an intervention to recognise and promptly manage early warning signs of relapse in schizophrenia with the aim of preventing relapse?We spoke with 88 mental health staff, 40 carers and 21 service users before we designed a system that used a mobile phone to help people monitor early warning signs. We included peer support to help people using the system reflect on their experiences. We hoped the overall system, called EMPOWER, would help people to be more in charge of their mental health. After consenting 86 people to the study, we were able to randomly assign 73 people either to use the EMPOWER system (42 people) or to receive their normal treatment alone (31 people). We used research measures over 1 year to help us better understand people’s experiences. We also involved carers (for example family or friends) and mental health service providers in the research.We found that it was possible to recruit people to the study and to gather research data. We also found that people used the EMPOWER system and found it acceptable. We found that those who used EMPOWER had a lower rate of relapse over 12 months than people who did not. They were also less likely to be fearful of relapse. We found that EMPOWER was likely to be cost-effective.This means that a study to investigate the effectiveness of a system to recognise and respond to early warning signs of relapse in schizophrenia is possible.