bluuebunny/crossref_metadata_2025 huggingface dataset:
Off-target gradient-driven flows in 3D simulations of ADITYA-Upgrade tokamak scrape-off layer plasma transport
Authors: Malwal Arzoo , Prasad Sahoo Bibhu , Sharma Devendra , Feng Yühe
Published: July 2024

Coupled plasma-neutral transport simulations are performed on ADITYA-Upgrade tokamak scrape-off layer (SOL) plasma, where flows in the core and SOL were measured to reverse signs with density variation. The simulations performed using the EMC3-Eirene plasma-neutral code combination incorporate the toroidally continuous high-field-side belt limiter placed in a moderate circular tokamak equilibrium. The development of mutually counter-propagating toroidal plasma flows in the top and bottom regions of both the SOL and core is recovered for relatively high upstream density cases with high input power (300 kW and 3 m2 s−1). The origin of the flows is traced to the poloidal density variation introduced by high recycling on the inboard localized belt limiter. The results are compared with similar observations, for example, in Doppler-shifted passive charge exchange line emission on the ADITYA-Upgrade (ADITYA-U) tokamak, highlighting the role played by residual stress in the total Reynolds stress. The external stimuli, such as a localized gas puff, are discussed as potential drivers of flow, via residual stress, based on the existing resonant model of the tokamak plasma rotation.
Redrawing the electoral map
Authors: Furlong Jamie , Jennings Will
Published: July 2024

The 2019 British general election saw a dramatic redrawing of the electoral map, with the Labour Party losing seats to the Conservatives in former heartlands in the North of England and Midlands. This long-term decline is not mirrored in major cities or in university towns, where Labour’s support has been increasing. What has driven these changes in electoral geography? This chapter introduces the mechanisms we believe are driving these significant shifts in the geographical basis of electoral competition. It outlines our core arguments regarding how demographic change, combined with party appeals to voters, give rise to changes in electoral geography. We illustrate the divergent trajectories of electoral support for Labour and the Conservatives in former industrial constituencies, deprived parts of major cities, cosmopolitan city suburbs, and university towns. The chapter sets out our analytical approach, why focusing on space and place matters, and gives an overview of the book’s structure.
Conclusion
Authors: Furlong Jamie , Jennings Will
Published: July 2024

This closing chapter summarizes our evidence and explanation of gradual changes—with notable accelerations and decelerations—in the geographical basis of electoral competition in England and Wales. We reflect on the drivers of changing electoral geography (long-term trends in social and economic structure and their geographic expression), putting Britain in comparative context. We provide an overview of the ways in which electoral outcomes have varied by region and place over time, and how the sociodemographic and economic predictors of voting at the constituency level have varied. We argue that there is substantial analytical and empirical value in identifying areas where parties defy the predictions of statistical models, and in using qualitative methods to better understand those cases. We suggest there is much uncertainty regarding how these developments might play out in the future, but argue that the importance of electoral geography should not be underestimated for the chances of parties taking office.
Resituating the Relevance of Alternatives for Causal Attributions
Authors: Sytsma Justin
Published: July 2024

Phillips et al. (2015) provide what looks like compelling evidence for explaining the impact of broadly moral evaluations on causal attributions in terms of the relevance of alternative possibilities. As part of a series of manipulation studies, they found that asking participants to describe what an agent could have done differently in a neutral case showed a similar effect to varying the morality of the agent’s action. Phillips and colleagues take this to show that broadly moral evaluations impact the alternative possibilities people see as relevant, which in turn impact their attributions. This leaves open the possibility that the manipulation impacts people’s broadly moral evaluations which in turn impact their attributions, however, rather than directly impacting attributions. But this alternative model conflicts with Phillips et al.’s account, while being compatible with competing explanations. These two models are tested using the same manipulation method and the results support the alternative model.
Truth-Conditional Variability of Color Ascriptions
Authors: Ziółkowski Adrian , Zyglewicz Tomasz
Published: July 2024

Recent experimental work has shown that the truth-value judgments regarding color predications (e.g., “the leaves on my tree are green”) are influenced by the context of utterance (Hansen & Chemla, 2013; Ziółkowski, 2021). Most explanations of this phenomenon focus on the semantics of color adjectives. However, it is not clear if these explanations do justice to the nuances of the empirical data collected thus far. In contrast to the adjectival explanations, Agustín Vicente (2015) argues that the context-sensitivity of color predications can result from the polysemy of the noun. We present the results of three studies designed to test this hypothesis: a traditional survey experiment (Study 1), an exploratory correlational study inspired by the semantic integration paradigm (Study 2a), and a follow-up experiment (Study 2b) that was designed to mitigate possible shortcomings of Study 2a. The results of our studies present preliminary evidence against Vicente’s theory.
Efficient risk-based collection of biospecimens in cohort studies: designing a prospective study of diagnostic performance for multicancer detection tests
Authors: Ramos Mark Louie F , Chaturvedi Anil K , Graubard Barry I , Katki Hormuzd A
Published: July 2024

In cohort studies, it can be infeasible to collect specimens on an entire cohort. For example, to estimate sensitivity of multiple multi-cancer detection (MCD) assays, we desire an extra 80 mL of cell-free DNA (cfDNA) blood, but this much extra blood is too expensive for us to collect on everyone. We propose a novel epidemiologic study design that efficiently oversamples those at highest baseline disease risk from whom to collect specimens, to increase the number of future cases with cfDNA blood collection. The variance reduction ratio from our risk-based subsample versus a simple random (sub)sample (SRS) depends primarily on the ratio of risk model sensitivity to the fraction of the cohort selected for specimen collection subject to constraining the risk model specificity. In a simulation where we chose 34% of the Prostate, Lung, Colorectal, and Ovarian Screening Trial cohort at highest risk of lung cancer for cfDNA blood collection, we could enrich the number of lung cancers 2.42-fold. The standard deviation of lung-cancer MCD sensitivity was 31%-33% reduced versus SRS. Risk-based collection of specimens on a subsample of the cohort could be a feasible and efficient approach to collecting extra specimens for molecular epidemiology.
Should regression calibration or multiple imputation be used when calibrating different devices in a longitudinal study?
Authors: Loop Matthew Shane , Lotspeich Sarah C , Garcia Tanya P , Meyer Michelle L
Published: July 2024

In longitudinal studies, the devices used to measure exposures can change from visit to visit. Calibration studies, wherein a subset of participants is measured using both devices at follow-up, may be used to assess between-device differences (ie, errors). Then, statistical methods are needed to adjust for between-device differences and the missing measurement data that often appear in calibration studies. Regression calibration and multiple imputation are two possible methods. We compared both methods in linear regression with a simulation study, considering various real-world scenarios for a longitudinal study of pulse wave velocity. Regression calibration and multiple imputation were both essentially unbiased, but correctly estimating the standard errors posed challenges. Multiple imputation with predicted mean matching produced close agreement with the empirical standard error. Fully stochastic multiple imputation underestimated the standard error by up to 50%, and regression calibration with bootstrapped standard errors performed slightly better than fully stochastic multiple imputation. Regression calibration was slightly more efficient than either multiple imputation method. The results suggest use of multiple imputation with predictive mean matching over fully stochastic imputation or regression calibration in longitudinal studies where a new device at follow-up might be error-prone compared to the device used at baseline.
Production and molecular weight variation of poly-γ-glutamic acid using a recombinant Bacillus subtilis with various Pgs-component ratios
Authors: Sawada Kazuhisa , Hagihara Hiroshi , Takimura Yasushi , Kataoka Masakazu
Published: July 2024

Poly-γ-glutamic acid (PGA) has been of interest as a sustainable biopolymer in industrial applications. PGA biosynthesis in Bacillus subtilis is catalyzed by a transmembrane protein complex comprising PgsB, PgsC, and PgsA. To determine the Pgs component responsible for PGA overproduction, we constructed recombinants in which the promoter of the host-derived pgs gene was replaced with another host-derived gene promoter. These recombinants were then transformed using high-copy-number plasmids with various pgs-gene combinations to enhance Pgs component in different ratios. Subsequently, PGA production was investigated in batch cultures with l-glutamate supplemented medium. The recombinant strain enhanced with pgsB alone significantly overproduced PGA (maximum production 35.8 g/L) than either the pgsC- or pgsA-enhanced strain. The molecular weight of the PGA produced with the pgsB-enhanced strain was also greater than that for the pgsC- or pgsA-enhanced strain (approximately 10-fold). Hence, PgsB enhancement alone contributes to PGA overproduction with increased molecular weight.
mLiftOver: harmonizing data across Infinium DNA methylation platforms
Authors: Chen Brian H , Zhou Wanding
Published: July 2024

Motivation

Infinium DNA methylation BeadChips are widely used for genome-wide DNA methylation profiling at the population scale. Recent updates to probe content and naming conventions in the EPIC version 2 (EPICv2) arrays have complicated integrating new data with previous Infinium array platforms, such as the MethylationEPIC (EPIC) and the HumanMethylation450 (HM450) BeadChip.

Results

We present mLiftOver, a user-friendly tool that harmonizes probe ID, methylation level, and signal intensity data across different Infinium platforms. It manages probe replicates, missing data imputation, and platform-specific bias for accurate data conversion. We validated the tool by applying HM450-based cancer classifiers to EPICv2 cancer data, achieving high accuracy. Additionally, we successfully integrated EPICv2 healthy tissue data with legacy HM450 data for tissue identity analysis and produced consistent copy number profiles in cancer cells.

Availability and implementation

mLiftOver is implemented R and available in the Bioconductor package SeSAMe (version 1.21.13+): https://bioconductor.org/packages/release/bioc/html/sesame.html. Analysis of EPIC and EPICv2 platform-specific bias and high-confidence mapping is available at https://github.com/zhou-lab/InfiniumAnnotationV1/raw/main/Anno/EPICv2/EPICv2ToEPIC_conversion.tsv.gz. The source code is available at https://github.com/zwdzwd/sesame/blob/devel/R/mLiftOver.R under the MIT license.
Reverse network diffusion to remove indirect noise for better inference of gene regulatory networks
Authors: Yu Jiating , Leng Jiacheng , Yuan Fan , Sun Duanchen , Wu Ling-Yun
Published: July 2024

Motivation

Gene regulatory networks (GRNs) are vital tools for delineating regulatory relationships between transcription factors and their target genes. The boom in computational biology and various biotechnologies has made inferring GRNs from multi-omics data a hot topic. However, when networks are constructed from gene expression data, they often suffer from false-positive problem due to the transitive effects of correlation. The presence of spurious noise edges obscures the real gene interactions, which makes downstream analyses, such as detecting gene function modules and predicting disease-related genes, difficult and inefficient. Therefore, there is an urgent and compelling need to develop network denoising methods to improve the accuracy of GRN inference.

Results

In this study, we proposed a novel network denoising method named REverse Network Diffusion On Random walks (RENDOR). RENDOR is designed to enhance the accuracy of GRNs afflicted by indirect effects. RENDOR takes noisy networks as input, models higher-order indirect interactions between genes by transitive closure, eliminates false-positive effects using the inverse network diffusion method, and produces refined networks as output. We conducted a comparative assessment of GRN inference accuracy before and after denoising on simulated networks and real GRNs. Our results emphasized that the network derived from RENDOR more accurately and effectively captures gene interactions. This study demonstrates the significance of removing network indirect noise and highlights the effectiveness of the proposed method in enhancing the signal-to-noise ratio of noisy networks.

Availability and implementation

The R package RENDOR is provided at https://github.com/Wu-Lab/RENDOR and other source code and data are available at https://github.com/Wu-Lab/RENDOR-reproduce
DualNetGO: a dual network model for protein function prediction via effective feature selection
Authors: Chen Zhuoyang , Luo Qiong
Published: July 2024

Motivation

Protein–protein interaction (PPI) networks are crucial for automatically annotating protein functions. As multiple PPI networks exist for the same set of proteins that capture properties from different aspects, it is a challenging task to effectively utilize these heterogeneous networks. Recently, several deep learning models have combined PPI networks from all evidence, or concatenated all graph embeddings for protein function prediction. However, the lack of a judicious selection procedure prevents the effective harness of information from different PPI networks, as these networks vary in densities, structures, and noise levels. Consequently, combining protein features indiscriminately could increase the noise level, leading to decreased model performance.

Results

We develop DualNetGO, a dual-network model comprised of a Classifier and a Selector, to predict protein functions by effectively selecting features from different sources including graph embeddings of PPI networks, protein domain, and subcellular location information. Evaluation of DualNetGO on human and mouse datasets in comparison with other network-based models shows at least 4.5%, 6.2%, and 14.2% improvement on Fmax in BP, MF, and CC gene ontology categories, respectively, for human, and 3.3%, 10.6%, and 7.7% improvement on Fmax for mouse. We demonstrate the generalization capability of our model by training and testing on the CAFA3 data, and show its versatility by incorporating Esm2 embeddings. We further show that our model is insensitive to the choice of graph embedding method and is time- and memory-saving. These results demonstrate that combining a subset of features including PPI networks and protein attributes selected by our model is more effective in utilizing PPI network information than only using one kind of or concatenating graph embeddings from all kinds of PPI networks.

Availability and implementation

The source code of DualNetGO and some of the experiment data are available at: https://github.com/georgedashen/DualNetGO.
259 Comparing the Use of Antibiotics Versus No Antibiotics in the Management of Acute Left-Sided Uncomplicated Diverticulitis: A Systematic Review and Meta-Analysis
Authors: Sokhal B S , Mostafa O E S , Ramasamy S , Spyridon R , Zaman S , Hajibandeh S , Hajibandeh S
Published: July 2024

Background

Acute uncomplicated diverticulitis (AUD) is a common cause of acute abdominal pain. Recent guidelines advise selective use of antibiotics in AUD patients. This meta-analysis aimed to compare the effectiveness of no antibiotics versus antibiotics in AUD patients.

Method

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to identify randomised controlled trials (RCTs) involving AUD patients which compared the use of antibiotics with no antibiotics. Pooled outcome data was calculated using a random effects model with 95% confidence intervals (CI).

Results

Five RCTs with 1934 AUD patients were included. 979 patients were managed without antibiotics (50.6%). Patients in the no antibiotic and antibiotic groups had comparable demographics (age, sex and body mass index) and presenting features (temperature, pain score and C-reactive protein levels). There was no significant difference in rates of complicated diverticulitis (OR: 0.61, 95% CI:0.27-1.36, p=0.23), abscess (OR: 0.51, 95% CI: 0.08-3.25, p=0.47) or fistula (OR: 0.33, 95% CI: 0.03-3.15, p=0.33) formation, perforation (OR: 0.98, 95% CI: 0.32-3.07, p=0.98), recurrence (OR: 0.96, 95% CI: 0.66-1.41, p=0.85) need for surgery (OR: 1.36, 95% CI: 0.47-3.95, p=0.37), mortality (OR: 1.27, 95% CI: 0.14-11.76, p=0.82) or length of stay (MD: 0.215, 95% CI: -0.43-0.73, p=0.61) between the two groups. However, the likelihood of readmission was higher in the antibiotics group (OR: 2.13, 95% CI: 1.43-3.18, p=0.0002).

Conclusions

There is no significant difference in baseline characteristics, clinical presentation and adverse health outcomes between AUD patients treated without antibiotics compared to those with antibiotics.
1141 Mortality and Re-Amputation Rates Following Below Knee Amputation: A Systematic Review and Meta-Analysis
Authors: Hennessy C , Pring T , Qureshi B , Kendal A
Published: July 2024

Aim

Below knee amputation (BKA) is undertaken in patients with diabetes or peripheral vascular disease, when limb sparing medical optimisation or vascular interventions are no longer feasible. Mortality and proximal re-amputation rates are poorly defined in the literature. We sought to perform a systematic review to examine mortality and reputation rates across the current literature.

Method

A systematic search was performed of the MEDLINE (via Pubmed), EMBASE, Cochrane and clinicaltrials.gov databases from inception to August 25th, 2022. Articles were screened by two independent reviewers with conflicts reserved by a third party. Inclusion criteria were all non-traumatic causes of lower limb amputation. Outcomes of interest included Mortality and occurrence of more proximal amputation.

Results

Studies from 12 countries encompassing a total of 41832 patients were included for analysis. Study dates ranged from 1987 to 2019. Of the total patient number, 38577 (92.2%) were from the USA, with 2599 (6.2%) from Europe and 656 (1.6%) remainder. The mean age at BKA was 70.46 years (Range 62-86). Weighted mortality was 37% (Range 4%-29%) at 1 year, 58% (Range 12% - 60%) at 2 years, 65% (range 19% - 81%) at 5 years and 84% (Range 71-96%) at 10 years. Five studies reported re-amputation rate at any time point (13% Range 1.16- 22%).

Conclusions

Mortality following BKA is still poor, even in contemporary studies. The few large multicentre studies are US based and in military veteran populations. More robust UK focused studies are needed to accurately inform clinical decision making for patients and clinicians.
564 The Assessment and Management of Anaemia in Patients Who Underwent an Emergency Laparotomy
Authors: Nantha Kumar D L , Cornish J , Da Silva L
Published: July 2024

Aim

Emergency Laparotomies (EmLap) carry a significant risk of morbidity and mortality. Peri and post-operative anaemia are associated with higher complication rates, delayed healing, and lethargy. This study aimed to assess the occurrence of anaemia in EmLap patients upon admission and discharge, as well as to evaluate its management.

Method

Data was collected from 260 participants undergoing EmLap from 2016 to 2019 that completed a follow up questionnaire in 2020, as part of PEEL 2 (Patients Experience of Emergency Laparotomy) in Cardiff, a retrospective cohort study. 34% of patients (n=90) had a Haemoglobin (Hb) level on admission and discharge and were included into the study. Information on transfusions and prescriptions of ferrous fumarate tablets during admission and on discharge were obtained from electronic records.

Results

46.7% (n=42) were anaemic at time of admission and further 19 patients were anaemic after surgery. 61 patients (68%) were discharged with anaemia post EmLap. Of the 61 patients discharged with anaemia only 10 (16%) were given treatment; 7 (11%) were offered a blood transfusion, 2 (3%) were prescribed ferrous fumarate tablets and 1 (1.6%) received a combination of both. Discharge summaries did not highlight the issue and follow up advice was not given to GPs.

Conclusions

2/3 of EmLap patients were discharged with anaemia and was not addressed. A greater understanding is needed to appreciate the impact of anaemia on EmLap patients’ such as fatigue levels. It can be avoided if a closer look at patients’ blood results is conducted and treated aligning with the NICE guidelines.
648 Predictive Factors for Subtotal Cholecystectomy
Authors: Warrell D , Pessoa L , Oh K E , Manson D , Nageswaran H
Published: July 2024

Introduction

Subtotal-cholecystectomy (STC) is a rescue procedure in dealing with difficult gallbladders undertaken when a critical view of safety is not possible to allow complete cholecystectomy, thereby avoiding complications.

Aim

Determine what patient factors increase risk of STC in patients undergoing elective laparoscopic cholecystectomy (LC) and therefore aid prediction in patients reduced suitability for day surgery.

Method

Data was collected between 01/01/2022 and 31/07/2023 from three hospitals throughout the Aneurin-Bevan University Health-Board, Wales, UK. All patients receiving elective LC had data collected on age, BMI, gender, ERCP preceding operation, surgical duration, length of stay and 30-day complications, amongst others.

Results

Of a total of 1060 patients were included in this study(77.36%female, 22.64%male), 81 where STC (7.64% of total LC; 56.8%female, 43.2%male). There were three 30-day mortalities, one of whom underwent STC(p= 0.09).

The overall complication rate was 6.41%, significantly raised in the STC group(13.58%vs5.82%;p=0.007). As expected, there was a significant increase in bile-leak following subtotal(12.35%vs1.12%; p=0.0001) , however, there was no increase significance for bleed (0%vs0.41%;p=0.5644), wound infection(0%vs3.68%;p=0.079), collection(0.09%vs0.51%;p=0.404) or bile duct injury(0%vs1.02%; p=0.0001).

Predictors for STC were higher age(70-79years;p=0.0016), male gender(p=0.0001), and ERCP preceding surgery(p=0.0001). Both length of stay(median 1vs 0days;p=0.0001) and length of procedure (median 122vs 76minutes;p=0.0001) were increased following STC. High BMI, diabetes(p=0.1991) and smoking(p=0.7921) had no association.

Conclusions

Subtotal cholecystectomy is a safe alternative when facing difficult cholecystectomy where critical view of safety is not achievable. Factors predicting STC were male gender, advanced age and prior ERCP.
280 Validating Artificial Intelligence Generated Patient Information Leaflets: A Patient Survey
Authors: Spinos D , Okonkwo O
Published: July 2024

Aim

Artificial Intelligence (AI) is a ground-breaking technological advancement known for its prowess in processing extensive datasets, gaining recognition among clinicians for its potential in improving patient care. While AI is successfully employed in analysing medical imaging, its use in developing patient information literature (PIL) is limited. Patient access to information aligns with modern healthcare values, emphasizing shared decision-making, a priority in the NHS. This study, conducted under single-blinded conditions, explores the acceptability of AI-generated patient documentation.

Method

Four PIL examples related to common ENT procedures and conditions were identified. ChatGPT 3.5 modified existing PILs, adjusting for a UK reading age of 14. AI-generated PILs were formatted to match trust documents. Participants were blinded to leaflet sources.

Results

In 59 responses from ENT outpatients over six weeks, both AI and Trust leaflets had comparable appearance scores (AI 6.82, Trust 6.85). Although a slight preference for Trust leaflets existed, it wasn't statistically significant (p=0.47). In overall presentation preference, most participants had no preference (N=27), with one-third favoring Trust leaflets and 13 preferring AI-generated ones. In explaining conditions, over half had no preference (N=36), while 16 favored human-generated and 7 AI-generated leaflets. Readability and understanding were similar, with 25 participants finding both equally easy to read. Overall satisfaction was comparable, with 26 equally satisfied, 18 preferring human-generated, and 15 AI-generated leaflets.

Conclusions

AI technology integrated into clinical practice holds potential to transform PIL quality and quantity. As AI accessibility increases, healthcare services must guide the public to safeguard the standard of provided information.
476 Enhancing Surgical Education: Assessing the Impact of Laparoscopic Simulators in Learning Surgical Anatomy and Improving Surgical Skills
Authors: Zilani N , Khan H
Published: July 2024

Aim

We assessed laparoscopic simulators' efficacy in teaching surgical anatomy and enhancing surgical skills, offering insights into their role in shaping surgical education.

Method

83 medical students and foundation year doctors were surveyed before and after a hands-on laparoscopic simulator session. Using a 5-point Likert scale, perceptions of the simulator's effectiveness in teaching surgical anatomy and the importance of laparoscopic simulator training for improving surgical skills were gauged. Attendees also rated the simulators’ effectiveness in providing information and exposure to Laparoscopic surgery. Scores underwent normality assessment via the Shapiro–Wilk test; a one-tailed T-test gauged statistical significance. Qualitative data was collected for deeper insights.

Results

Attendees exhibited a significant increase in belief in laparoscopic simulators as an effective means to learn surgical anatomy (mean before = 4.26, after = 4.49, p = 2.41 x 10-3). Agreement increased for the necessity of laparoscopic simulator training in medical education for improving surgical skills (mean pre-event = 4.36, after = 4.55, p = 3.31 x 10-3).

Conclusions

A notable surge in support for integrating laparoscopic simulators in medical education emerged, indicating a promising avenue for enhancing anatomical understanding in minimally invasive contexts. The positive shift underscores the increasing recognition of laparoscopic simulators as valuable tools for teaching surgical anatomy and skills. Future research should explore the impact of laparoscopic simulation training on long-term outcomes.
654 Laparoscopic Cholecystectomy in Class III (Morbid) Obesity
Authors: Warrell D , Pessoa L , Oh K E , Manson D , Nageswaran H
Published: July 2024

Background

High Body Mass Index (BMI) has been associated with increased operative-time, conversion to open-surgery and poorer outcomes. Criteria for day surgery often includes BMI, with centres excluding patients with BMI>40kg/m2 . However, as cholecystectomies are routinely performed laparoscopically with low complication rates in patients with higher BMI, this cut-off is being reviewed.

Aim

To examine outcomes of Laparoscopic Cholecystectomy in patients with increased BMI, particularly when comparing patients with morbid obesity (Class-III;BMI>40 kg/m2) to those with lower BMI.

Method

Data was collected between 01/01/2022 and 31/07/2023 from hospitals throughout the Aneurin-Bevan University Health-Board, South Wales, UK. Data on BMI, surgical indication, operative duration, length of admission and 30-day complications, amongst others, was collected.

Results

This study included a total of 1007 patients (77.92% female, 22.08% male). Patients were placed into 5 BMI categories: BMI<25(n=117),25-29(n=284),30-34(n=285),35-39(n=193), and>40(n=135). The median BMI was 31kg/m2 and overall complication-rate 5.36%. There were three 30-day mortalities, one in BMI category <25(p=0.19) and two in 25-29(p=0.06).

When comparing patients with BMI>40 to those with lower BMI there was no significant difference in complications including bile-leak (0%vs1.79%;p=0.35), significant bleed (0.10%vs0.20%;p=0.41) or bile-duct injury (0%vs0.1%;p=0.71). The duration of surgery was increased, almost reaching statistical significance (83.5vs78mins;p=0.05). Due to existing Health board admission criteria, length of admission was significantly raised for BMI>40 (median1vs0days;p=0.00).

Conclusions

This retrospective study finds Laparoscopic Cholecystectomy safe in patients with Class-III obesity with no increased association with intraoperative or post-operative complications. Criteria for day-surgery based solely on BMI>40 appears inappropriate.
1021 Accuracy of Clinical Coding in General Surgery and Its Financial Impact
Authors: Singh A , Adhya S , Khan N , Perera H , Janakan G , O’Hara E , Udall A
Published: July 2024

Aim

To analyse the clinical coding performed at a tertiary centre after patient discharge and compare it with the clinical summary to identify any inconsistency and its financial implications.

Method

Fifty patient episodes were selected randomly between June 2023 and August 2023 under the general surgery department. Clinical notes, discharge summaries and existing clinical codes were scrutinized by liaison with the clinical coding department. Financial losses were noted, and the summary was later presented at the local clinical governance meeting.

Results

A total of £38,760 was lost in 50 patients. Loss incurred was primarily due to incomplete information in the discharge summary, related to the patient’s comorbidities, incomplete diagnosis, and procedure/investigations. These results were discussed in a clinical governance meeting and a poster was made to disseminate the conclusion and improve the quality of the discharge summary.

Conclusions

A total of £38,760 of funding was lost due to discrepancies in the clinical coding. An intervention in the form of a poster and teaching session was conducted for junior doctors and a repeat cycle is planned in the due course of time to improve the quality and minimise the loss of funding.
278 Outpatient "Did Not Attend" Episodes: A Cohort Study Investigating Influencing Factors
Authors: Peter B , Hughes J , Kourounis G , Kanakala V
Published: July 2024

Aim

Outpatient "Did Not Attend" (DNA) episodes represent a significant financial burden to healthcare systems, with an estimated cost of £1 billion for the NHS. Understanding factors that contribute to DNA episodes is crucial for optimizing healthcare resource utilization. We examined a cohort of outpatient clinics within the general surgery department at South Tees Hospitals NHS Foundation Trust to identify factors associated with DNA episodes.

Method

A prospectively collected database of all outpatient clinics was interrogated from 01/01/2021, to 31/03/2023. Information on patient age, gender, appointment type (new vs. follow-up, face-to-face vs. remote), index of multiple deprivation (IMD) decile, and driving distance was recorded for each clinic attendance.

Results

Of 19,769 clinic appointments, 1,509 (8%) resulted in DNAs. Disproportionate number of patients with DNAs resided in the lowest IMD decile (19%), compared to other deciles (range: 6.4%-10%). Driving distance did not differ between attended (median: 16 km, IQR: 6-30 km) and DNA groups (median: 15 km, IQR: 5-30 km). DNA rates did not vary between remote (8%) and face-to-face (7%) clinics. Multivariable binary logistic regression found older age, IMD, and hospital site as predictors of outpatient DNA. Individuals who were younger and from the lowest IMD decile were more likely to DNA.

Conclusions

Outpatient DNA is multifactorial. Travel distance/duration and remote consultations did not influence attendance in our cohort. Working-age patients and those residing in lower IMD deciles were more likely to DNA. Solely relying on remote consultations may not be sufficient to effectively address DNA episodes.
765 Enhancing the Quality of Referrals to Vascular Surgery at a District General Hospital: A Closed-Loop Quality Improvement Project
Authors: Boyce L
Published: July 2024

This quality improvement project aimed to improve the completeness of referrals to vascular surgery from in-patient wards and the Sameday Emergency Care unit at a UK district general hospital. We implemented a comprehensive vascular surgery proforma to enhance the quality of referrals to the department.

Referrals made between 01/01/23 and 01/03/23 were assessed according to Professional Record Standards Body (PRSB) guidelines, which outlines the necessary information to be included in clinical referrals. The new proforma was introduced to all hospital clinicians, enabling them to email completed referrals to a dedicated vascular surgery inbox. To evaluate the impact of the new system, referrals were re-audited between 12/05/23 and 13/07/2023 using the same PRSB criteria.

Significant improvements were observed in the completeness of referrals, as indicated by the percentage of fulfilled PRSB criteria: patient demographics (60% vs. 100%), referrer details (51% vs. 100%), reason for referral (93% vs. 100%), relevant clinical risk factors (60% vs. 95%), medication history (60% vs. 100%), family history (40% vs. 84%), social history (47% vs. 93%), patient ideas concerns and expectations (40% vs. 81%), examination findings (60% vs. 93%), and investigation findings (63% vs. 91%). The median number of fulfilled criteria per referral increased from 2.5 to 9 (out of 10), demonstrating a substantial improvement (p < 0.0001).

Our dedicated vascular surgery referrals proforma had a significant positive impact on the completeness of referrals to the department. This change has the potential to enhance continuity of care, improve clinical prioritisation, promote patient safety, and enhance the overall efficiency of our service.
835 FAMiSH: Fasting Prior to Emergency General Surgery in Hospital – Quality Improvement Project Protocol
Authors: Khirfan H , Shams O , Alexiadis A
Published: July 2024

Aim

This study was conducted to evaluate adherence to preoperative fasting guidelines at the Royal Devon University Hospital, focusing on safety and reducing prolonged fasting particularly in geriatric, diabetic or co-morbid patients.

Method

Data were gathered anonymously over 2 cycles for 4 weeks through patient records and questionnaires to access patient given instructions for fasting to solids and fluids. All patients with emergency surgeries more than 6 hours later were included, excluding emergency operations (NCEPOD) 1 or 2a/2b classification. Issues such as inadequate communication, excessive fasting and medication mismanagement were addressed.

Results

Cycle one revealed that 25% of patients fasted for more than 6 hours, 56.25% did not consume liquids for more than 12 hours, and 25% abstained from drinking for more than 8 hours preoperatively. It was noted that guidelines were not thoroughly adhered to. Some patients missed medications, besides diabetics with prolonged hours of fasting. We have provided a session for junior doctors and nurses, educating on ASA guidelines, and encouraging individualised fasting plans for patients. Information leaflets were distributed to patients for surgery. In the second cycle only 20% and 24% of patients didn’t follow fasting guidelines for solids and liquids respectively compared to 68.75% of patients receiving inappropriate instructions in first cycle, showing significant improvement in care.

Conclusions

In our study we have noted improvement in departmental focus on adherence to fasting guidelines, which advise abstaining from solids up to 6 hours and drinks up to 2 hours prior to surgery, aiding patient safety and improvement of quality of care.
61 Investigating Barriers to Surgical Careers and Addressing the Growing Need for Diverse Role Models in Surgery Through a Mentoring Event
Authors: Hussain S , Jaffar-Karballai M , Beni R , Bridgens A , Gelfer Y
Published: July 2024

Aim

Attrition of females during surgical training remains a significant problem; only 14.7% become consultants. This project aimed to assess barriers to surgical careers and provide diverse role models to support uptake.

Method

A mentoring event was held, first-of-its-kind locally, including surgeons from diverse backgrounds and career stages discussing career journeys, work-life balance, parenthood, and less-than-full-time training. Surveys were disseminated before (“pre-event”), immediately after (“post-event”), and five months later (“follow-up”), to assess longevity of impact. Surveys involved open-ended and Likert-scale questions (‘10=very-much’; ‘0=not at all’) across a series of statements assessing opinion regarding surgical careers. Descriptive statistics and thematic qualitative analysis were undertaken.

Results

Students identifying as female across all year-groups from London completed pre-event (n=25), post-event (n=25), and follow-up (n=11) surveys. More students were considering surgical careers following the event (score ≥7/10: pre-event 76%; post-event 92%; follow-up 91%). The most common uncertainties and worries reduced after the event: work-life balance (pre-event 48%; post-event 24%); and parenthood (32%;24%). However, remaining concerns included the training pathway (32%;36%) and competitiveness (20%;36%), with 18% citing sexual harassment as a deterrent at follow-up. 84% scored ≥8/10 stating the event strengthened their decision to become a surgeon. The event met all expectations, exceeding in 28%. The format was well received (60% scoring 10/10), and 96% signed for additional mentoring.

Conclusions

The value of mentoring through a single evening and early support in decision making is potentially beneficial to career progression for aspiring surgeons. Continuous support in the form of further evenings and long-term mentoring should be explored.
261 PLASTICS-UK (Plastic Surgery Teaching in the Undergraduate Curriculum of Medical Students - United Kingdom): A UK National Collaborative Evaluation of Plastic Surgery in the Undergraduate Medical Curriculum
Authors: Gupta S , Luu J , Shah V , Barnes S ,   PLASTICS-UK Collaborative, Miranda B
Published: July 2024

Aim

Plastic surgery incorporates all anatomical regions, age groups and tissue types; clinical challenges vary from trauma and burns to congenital defects and cancer. Although ∼50% of workload is trauma, it is often misperceived to revolve around cosmetic work. This study investigated national undergraduate plastic surgery exposure and perceptions amongst UK medical students.

Method

Ethical approval was granted. Permission was obtained from 27 UK medical schools. A national survey was conducted (31/03/23-07/07/23). National trends were analysed, with comparisons between established and new medical schools, and surgical and non-surgical aspirants.

Results

Data included 2513 students from 27 UK medical schools. 29.2% had surgical career aspirations. Students perceived plastic surgery as challenging, competitive, and impacting quality-of-life, however most had no formal teaching (56.3%); merely 6.2% had clinical exposure. Breast reconstruction was the most recognised procedure; the least were head and neck cancer surgery, fasciotomy, and hand fracture repair. Students at new medical schools were more likely to overestimate private practice and pursue the profession, but less likely to have sutured (22.2% vs 34.7%). Surgical aspirants were less likely to overestimate private practice, but more confident in their understanding of plastic surgery, and more likely to pursue it (p<0.001).

Conclusions

This was the largest UK national plastic surgery undergraduate curriculum survey to-date. A greater need for undergraduate plastic surgery teaching was determined. Significant heterogeneity across medical schools was identified. Formation of a national undergraduate plastic surgery curriculum, led by professional bodies, may tackle disparities amongst medical schools, improve accessibility and facilitate knowledge in hand trauma and burns.
948 Learning Curve for Single Surgeon Approach of Laparoscopic Peritoneal Dialysis Catheter Insertion Using Freehand Robotic Assistant
Authors: Stephenson J , Sivaprakasam R , Praveen K
Published: July 2024

Introduction

A single surgeon approach to laparoscopic peritoneal dialysis catheter insertion can offer improved efficiency to surgical lists as well as freeing up surgeons to complete other operations or ward jobs. Simple, low risk laparoscopic procedures which can be completed quickly with the aid of a robotic assistant can help hospitals improve efficiency of surgical departments. This study aims to assess the learning curve of a single surgeon approach using the Freehand robotic assistant in peritoneal dialysis catheter insertion.

Method

Seventy-two cases were analysed over a period of three years from 2020-2023, operations involving the Freehand robotic assistant were performed by a single consultant surgeon. The duration of the procedure was one of the main factors evaluated for assessing learning curve. Other factors considered were re-do procedures and post-operative complications.

Results

Total mean operating time was 30.23 minutes. The peak point of the CUSUM chart for operating time was found at case 30, from this point onward trend began to decrease. From the 72 cases 6 had post-operative complications due to peritonitis and 2 had to be re-done due to inadequate positioning.

Conclusions

CUSUM chart indicated proficiency was gained at operation 30. There were minimal replacements necessary and only 6 cases that had post-operative complications all within the first 25 operations. This implies a short learning curve with great potential for improving efficiency with the use of the Freehand robot in simple laparoscopic procedures such as peritoneal dialysis catheter insertion.
599 From Classroom to Theatre: Analysis of an Undergraduate Surgical Mentorship Scheme to Support Tomorrow’s Surgeons
Authors: Kerdegari N , Tandanu E , Lee K , Zakri R , Chandak P , Dasgupta P
Published: July 2024

Aim

Exposure to surgery during medical school is limited. We ran a mentorship scheme pairing students at a medical school with local surgeons to improve undergraduate insight. We evaluated the effectiveness of mentorship in increasing surgical exposure and drivers for students seeking surgical mentorship.

Method

35 surgeons across 7 specialties were recruited and matched with 37 students in years 2-4 for 7 months. Quantitative and qualitative evaluation was done with pre-, mid-and post-scheme questionnaires. Students rated confidence across pursuing a career in surgery, surgical exposure, career insight, understanding the application process, contacts, portfolio development, research knowledge and pursuing extra-curricular activities related to surgery using a 5-point Likert scale. Paired t-tests were performed to measure students’ confidence before and after the scheme.

Results

Of students that completed all 3 questionnaires (n=21), conducting research/audit was most frequently selected as a main goal (81.0%), followed by theatre experience (66.7%) and career progression support (28.6%). The number of students that had assisted in theatre increased by 50%. There was a statistically significant improvement (p<0.05) in confidence ratings across all domains. The greatest improvement was seen in understanding of the application process from 2.33 to 3.52 (p=0.00). 95.2% would recommend the scheme.

Conclusions

Students seek mentorship to develop their clinical and academic skills. Students gained significantly more surgical experience and were better equipped with the knowledge required to pursue a surgical career. Mentorship schemes are invaluable in supplementing the undergraduate curriculum and empowering students.
63 Developing a 3D in Vitro Schwann Cell Model of Myelination for Peripheral Nerve Injury
Authors: Christou A
Published: July 2024

Aim

This study investigated the effectiveness of fabricating engineered neural tissue (EngNT) to develop a 3D in vitro model of myelination for peripheral nerve injury. Additionally, the effect of metformin and sulindac sulfide in nerve regeneration was evaluated by assessing neurite growth in both monolayer and 3D co-culture systems.

Method

Neuronal cells (NG108-15 and SH-SY5Y cell lines) were treated with metformin for 72 hrs in an Incucyte® live-cell analysis system. EngNT cellular collagen gels were fabricated using Schwann cells (SCL4.1/F7), SCL4.1/F7:NG108-15 (1:1) cells or harvested rat dorsal root ganglion cells. NG108–15 cells were co-cultured with SCL4.1/F7 cellular gels. 3D EngNT co-cultures were treated with metformin and sulindac sulfide for 72 hrs. EngNT cellular gels were analysed with transmission electron microscopy (TEM).

Results

TEM evaluation of EngNT co-cultures demonstrated the enfoldment of neurones by Schwann cells resulting in cell-cell contacts and myelination was identified. NG108-15 and SH-SY5Y cells exhibited significant neurite growth with 100 μM metformin being the optimal dose (151.4 ± 3 μM and 108.0 ± 12 μM respectively). Increased neurite growth of NG108-15 neurones was demonstrated with 100 μM (179.3 ± 2 μM) metformin treatment in 3D EngNT. Additionally, significant neurite growth was demonstrated following treatment with 100 μM (203.9 ± 32 μM) sulindac sulfide.

Conclusions

A 3D EngNT in vitro co-culture model of Schwann cell myelination was developed illustrating the cell-cell interaction between Schwann cells and neurones and the formation of myelin in the peripheral nervous system. Metformin elicits significant positive results on neurite growth in vitro highlighting its therapeutic potential in PNI.
522 A Snapshot Audit of Incisional Hernia Rates Following Colorectal Cancer Resection
Authors: Hughes A , Smith L
Published: July 2024

Aim

Incisional hernia is a common complication of colorectal surgery. Recent European Hernia Society guidelines recommend strategies such as small bites closure and off-midline incisions to reduce incisional hernia rates. We aimed to evaluate our centres incisional hernia rate and performance against these categories

Method

All patients undergoing surgery for colorectal cancer in 2020 were included. Operative details including incision location and closure method were collected. Post-operative CT scans were assessed and correlated with clinic letters to determine presence of incisional hernia. Patients were excluded if they underwent re-operation through the midline within 12 months, or if had no imaging after 12 months.

Results

118 patients were included. The incisional hernia rate was 31.4% at a mean follow-up of 24.9 months. Large bites closure (Hughes or loop PDS, n=80) had a higher incisional hernia rate compared to small bite closure ( n=38) (35.0% vs 23.6%). Incisional hernia rates were 44.1% in laparotomy incisions, 37.2% in midline extraction sites, 8% in Pfannensteil extraction sites and 0% in transverse extraction sites. Overall, IH rates in midline incisions were 40.7%, compared to 6.3% in off-midline incisions.

Conclusions

Incisional Hernia rates remain high following colorectal cancer surgery in our institution. Small bites closure and off-midline incisions appear to reduce this risk, but use of these techniques remains low. Work is ongoing to identify and implement strategies to improve uptake of small bites and off-midline incisions.