bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparing the spectrum of Schrödinger operators on quantum graphs
Authors: Bifulco Patrizio , Kerner Joachim 
Published: August 2023

We study Schrödinger operators on compact finite metric graphs subject to

δ
\delta

-coupling and standard boundary conditions. We compare the

n
n

-th eigenvalues of those self-adjoint realizations and derive an asymptotic result for the mean value of deviations. By doing this, we generalize recent results from Rudnick et al. [Comm. Math. Phys. 388 (2021), pp. 1603–1635] obtained for domains in

R

2

\mathbb {R}^2

to the setting of quantum graphs. This also leads to a generalization of related results previously and independently obtained by Sofer [Spectral curves of quantum graphs with

δ
s

\delta _s

type vertex conditions, arXiv:2212.09143, 2022] and Band et al. [Differences between Robin and Neumann eigenvalues on metric graphs, arXiv:2212.12531, 2022] for metric graphs. In addition, based on our main result, we introduce some surface measures for a (quantum) graph which might prove useful in the future.
Comparing Location Data From Smartphone and Dedicated Global Positioning System Devices: Implications for Epidemiologic Research
Authors: Thierry Benoit , Stanley Kevin , Kestens Yan , Winters Meghan , Fuller Daniel 
Published: August 2023

Abstract
In this study, we compared location data from a dedicated Global Positioning System (GPS) device with location data from smartphones. Data from the Interventions, Equity, and Action in Cities Team (INTERACT) Study, a study examining the impact of urban-form changes on health in 4 Canadian cities (Victoria, Vancouver, Saskatoon, and Montreal), were used. A total of 337 participants contributed data collected for about 6 months from the Ethica Data smartphone application (Ethica Data Inc., Toronto, Ontario, Canada) and the SenseDoc dedicated GPS (MobySens Technologies Inc., Montreal, Quebec, Canada) during the period 2017–2019. Participants recorded an average total of 14,781 Ethica locations (standard deviation, 19,353) and 197,167 SenseDoc locations (standard deviation, 111,868). Dynamic time warping and cross-correlation were used to examine the spatial and temporal similarity of GPS points. Four activity-space measures derived from the smartphone app and the dedicated GPS device were compared. Analysis showed that cross-correlations were above 0.8 at the 125-m resolution for the survey and day levels and increased as cell size increased. At the day or survey level, there were only small differences between the activity-space measures. Based on our findings, we recommend dedicated GPS devices for studies where the exposure and the outcome are both measured at high frequency and when the analysis will not be aggregate. When the exposure and outcome are measured or will be aggregated to the day level, the dedicated GPS device and the smartphone app provide similar results.
63 Analysis of the Intra and Post-Operative Complications of Minimally Invasive vs Open Adrenalectomy in Patients with Phaeochromocytoma: A Systematic Literature Review
Authors: Papaioannou C , Druce M 
Published: August 2023

Abstract

Aim
Phaeochromocytoma is a rare type of neuroendocrine tumour arising from the chromaffin cells of the adrenal medulla. The Endocrine Society suggest that minimally invasive (laparoscopic or robotic) adrenalectomy (MIA) should be performed unless the tumour is &gt;6cm or invasive where open adrenalectomy (OA) is preferred. The aim of this review is to describe the intra and post-operative complications between the two surgical approaches.

Method
A thorough search was conducted on PubMed, EMBASE and Cochrane Library to find papers which analysed the intra and post-operative morbidity of adult patients with phaeochromocytoma. This review included only original studies written in English, after the year 2000. Our search strategy identified 10 papers which fulfilled our inclusion criteria. The PRISMA system was used for standardization.

Results
Haemodynamic instability was the major intra-operative complication. Patients having OA had significantly more frequent and greater fluctuations in their blood pressure during surgery. This was both in terms of hypertensive crises and hypotension too. Furthermore, significantly more patients required blood transfusion if they had an OA due to the higher degree of blood loss compared to the MIA (p&lt;0.05).
The median number of days spent in the hospital post-operatively was significantly more for patients having OA (8.3 days vs 4.2 days). Finally, two papers analysing the number of patients having post-operative cardiovascular complications deduced that a higher proportion sustained such complications after OA than MIA (p = 0.002 and p = 0.041).

Conclusions
The results highlight the superiority of the MIA in terms of safety during and shortly after the procedure.
677 Amide Proton Transfer-Weighted Imaging Versus Diffusion-Weighted Imaging for Monitoring Treatment Response in Glioma Patients: A Systematic Review and Meta-Analysis
Authors: Chansiriwongs A , Welch A 
Published: August 2023

Abstract

Aim
Monitoring treatment response in glioma (GM) patients remains a challenge, as tumour recurrence (TR) and treatment-related injury (TRI) both appear similarly on standard magnetic resonance imaging (MRI). Although diffusion-weighted MRI (DWI) is gold standard, equivocal patients still undergo invasive biopsies for diagnosis. Amide proton transfer-weighted MRI (APTw) may more accurately differentiate TR from TRI, reducing surgical intervention rates. Hence, this systematic review and meta-analysis aimed to determine how APTw compares to DWI in the identification of TR from TRI.

Method
A search strategy was used to select studies investigating the diagnostic ability of DWI or APTw in detecting TR from Ovid MEDLINE ®, Ovid Embase, Web of Science, Cochrane Central Register of Controlled Trials, and Thai Clinical Trials Registry. Selection criteria were applied to retrieve studies and methodologies critically appraised according to the QUADAS-2 tool. Conclusions from studies were synthesised, and the sensitivity and specificity for TR detection pooled.

Results
18 studies were included in the analysis (11 DWI, 6 APTw, 1 both). For TR, APTw signal measured significantly higher, whereas apparent diffusion coefficients derived from DWI images were significantly lower. In DWI studies, combined sensitivity and specificity for TR was 84.4% (95% CI, 72.5%-91.7%) and 81.2% (95% CI, 67.9%-89.8%) accordingly. Meta-analysis was not performed for APTw due to limited study numbers. In general, studies had low methodological quality and were associated with a risk of bias.

Conclusions
Overall, though comparisons between DWI and APTw in monitoring GM treatment were inconclusive, this study supports the potential use of APTw in neurosurgery.
891 A Systematic Review and Narrative Synthesis on the Efficacy of Bisphosphonate Therapy in the Management of Diffuse Sclerosing Osteomyelitis
Authors: Nasri Elmi S , Van Der Lith S , Hawesa N , Abukhder M 
Published: August 2023

Abstract

Aim
Diffuse Sclerosing Osteomyelitis (DSO) of the mandible is a rare condition, characterised by recurrent severe pain, and functional disturbances such as trismus. Management of DSO through antibiotics, steroids, and analgesia has been generally unsatisfactory. Several articles have suggested the use of bisphosphonate therapy as an alternative treatment option to achieve long-lasting symptom improvement. We aim to summarise all evidence relating to the efficacy of bisphosphonate therapy in DSO.

Method
A systematic review protocol was registered with PROSPERO and reported in accordance with the Preferred Reporting for Items for Systematic Reviews and Meta-Analyses. Comprehensive electronic search strategies of six databases were developed. Studies were screened according to the inclusion and exclusion criteria by two independent reviewers.

Results
Eight articles were eligible for inclusion. A total of 102 patients with a confirmed diagnosis of DSO received bisphosphonate treatment following a trial of conservative management. All studies reported significant reduction in levels of pain and swelling, and a reduction in cumulative doses of analgesics. Majority of patients reported that bisphosphonate therapy provided long-lasting symptom improvement. Three studies reported improvements in maximal mouth opening, with one study reporting a mean increase of 9.6mm. Improvements in panoramic radiographs and cone beam CT scans were also observed in five studies, with four patients demonstrating almost normal-to-normal bone architecture. Finally, all studies reported no long-term complications.

Conclusions
Bisphosphonate therapy does appear to be a promising treatment option for DSO. It has shown to improve symptoms and radiological features, providing long-term benefits. Further prospective studies are required to finetune treatment protocols.
1247 A Vascular Surgeon's Dilemma - Biodegradable Versus Non-Biodegradable Drug Releasing Stents: A Systematic Review and Meta Analysis
Authors: Shah A , Kumar N 
Published: August 2023

Abstract

Aim
Vascular stents are the best-known interventional treatment for cardiovascular disease, and variation in available stents has increased significantly over time. Despite the rapidity of new prototype releases, critical cross-comparisons fail to maintain the same rate, therefore causing confusion for vascular surgeons. Research is most notably lacking between biodegradable-polymer sirolimus-eluting stents (BP-SES) and permanent-polymer sirolimus-eluting stents (PP-SES). Consequently, a systematic review with meta-analysis was conducted evaluating clinical outcomes.

Method
Medline, Embase, and Scopus databases were searched using relevant synonyms of “biodegradable”, “sirolimus” and “stent”, with the final search being conducted on the 4th of November 2022. Reference lists were also screened. The clinical outcomes investigated were stent thrombosis (ST), myocardial infarction (MI), target vessel revascularisation (TVR), target lesion revascularisation (TLR), and death. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

Results
Five clinical trials directly comparing clinical outcomes between BP-SES and PP-SES were ultimately identified for inclusion. For all five outcomes investigated, no statistically significant difference (p&gt;0.05) was found between the BP-SES and the PP-SES recipients. Pooled odds ratios of 0.86 (95% CI:0.44-1.65), 0.75 (95% CI:0.32-1.74), 1.12 (95% CI:0.54-2.32), 1.14 (95% CI:0.38-3.38) and 0.95 (95% CI:0.51-1.77) were calculated for ST, MI, TVR, TLR and death respectively.

Conclusions
Although there is some evidence to suggest BP-SES are noninferior to PP-SES, concrete conclusions cannot yet be drawn due to the paucity of research in this field. Further clarity from randomised control trials will aid additional examination and improvement in stent materials and outcomes.
15 Impact of Mentoring of Underrepresented Minorities in Undergraduate Medical Education: A Systematic Review
Authors: Feeley A , Feeley I , Sheehan E , Queally J 
Published: August 2023

Abstract

Aim
The aim of this review is to evaluate the impact of structured mentoring programs on underrepresented minorities in undergraduate medical education.

Method
A comprehensive search strategy was performed of electronic databases including PubMed, Ovid Medline, and EMBASE between January- September 2022 in accordance with PRISMA guidelines. Both qualitative and quantitative outcomes including characteristics of the mentoring structure explored within each study were collected, and differences in study outcomes analysed.

Results
In total 17 studies were included for analysis. Mentoring within underrepresented minorities resulted in an increase in research opportunities, exam performance, medical specialty applications and residency matching. Structured feedback yielded positive experiences by both mentors and mentees participating in programs, with both emotional and cultural competence issues explored across studies included for analysis.

Conclusions
Mentoring for medical students underrepresented in medicine across mentoring relationships including peer, senior, formal, and informal structures yield positive outcomes within research, academic modules, and career pathways. Future applications of mentoring programs should consider the use of tandem mentoring from both senior and peer mentors to optimise benefits URM students derive from each mentoring relationship.
526 Combining Sarcopenia and ASA Status to Inform Emergency Laparotomy Outcomes: Could It Be That Simple?
Authors: Karolewski J , Ming Y J , Howley P , Holmes M , Gani J , Pockney P 
Published: August 2023

Abstract

Aim
Emergency laparotomy mortality prediction tools are usually complex multipoint scoring systems. Our aim was to assess a 2 point system comprising radiological sarcopenia plus simplified ASA (PM;L3/sASA) as a potential predictor of 30-, 90- and 365- day mortality in Emergency Laparotomy patients, and compare this to current widely used tools such as NELA, P-Possum and ACS-NSQIP.

Method
A retrospective analysis was conducted across four hospitals, identifying 500 patients who underwent emergency laparotomies between 2016-2017 and had contemporaneous abdomino-pelvic CT scans. Radiological sarcopenia was measured using the PM:L3 ratio on a cross-sectional axial CT slice. PM:L3, NELA, ACS-NSQIP, and P-POSSUM, as well as simplified ASA (sASA) were retrospectively calculated and assessed as potential predictors of 30-, 90-, and 365-day mortality.

Results
ACS-NSQIP, NELA, P-POSSUM and PM:L3/sASA were each statistically significant predictors of 30-day, 90-day and 365-day mortality (p&lt;0.001). Logistic regression models of 30-, 90- and 365-day mortality containing just the two predictors PM:L3 and simplified ASA exhibited AUCs of 0.838, 0.805 and 0.775 respectively, which are comparable with the best currently used predictors ACS-NSQIP and NELA.

Conclusions
Combining PM:L3 with ASA scores appears to be a significant predictor of 30-, 90-, and 365-day mortality in emergency laparotomy patients in Australia. The results are comparable with some of the best performing widely used risk assessment tools and provide a more time-efficient and accessible method of performing risk assessments in Emergency Laparotomy patients.
812 Decision Making in Emergency Laparotomy – Do Trainees and Consultants Take Decisions Differently? Preliminary Results of an International Quality Enhancement Initiative (DILEMMA Study)
Authors: Perin G , Bellio G , Ghirardo S , Favero A , Hormis A , Cresswell A 
Published: August 2023

Abstract

Aim
The aim of our study is to assess how professionals take decisions when evaluating suitability of patients for emergency laparotomy and compare judgement profiles between trainees and consultants.

Method
We created and validated a dataset of 90 short case vignettes based on real patients admitted with surgical pathology correctable only via an emergency laparotomy. We removed any information concerning real life outcomes. We submitted the vignettes to consultants and trainees in surgery, anaesthesia, and intensive care, asking them if they would or not offer an emergency laparotomy. The data was analysed using Judgement Analysis methodology (binomial logistic regression) to identify factors playing a role in the decision-making process. We then compared judgement profiles, accuracy scores (the lower the value the higher the likelihood of operating on patients that survived at 30 days), and inconsistency between trainees and consultants and between trainees of different grades.

Results
Twelve centres provided data (4 from Italy, 7 from the UK, 1 from Greece). 47 consultants, 9 SAS doctors, 28 higher trainees, 13 core trainees or equivalent took part in the study. Average concordance between decision makers and real life was 78.9%. Median accuracy was 16.5 (IQR 11-30.5). Median inconsistency score was 13% (IQR 7%-20%). Accuracy and inconsistency were better for consultants and worse for trainees. Judgment Analysis demonstrated differences between grades, specialities, and institutions.

Conclusions
Different clinicians, when faced with the same information, make different decisions. Accuracy and consistency differed between trainees and consultants.
227 Investigating the Use of Flavin Mononucleotide & Cell Free Mitochondrial DNA as a Biomarkers of Ischaemic Damage to Livers & Kidneys Before Transplant Surgery
Authors: Takyi C 
Published: August 2023

Abstract

Aim
Before accepting an organ for transplantation, it is important to ensure it is safe to use. Flavin mononucleotide (FMN) has been demonstrated to be an accurate predictor of 90-day graft loss in liver transplant surgery. Previous studies revealed that cell free mitochondrial DNA (cf mtDNA) is predictive of ischemic acute kidney injury in kidney transplantation.
There is no validated scoring system or biomarker in clinical use to aid the decision-making process before transplantation. Consequently, transplant surgeons accept or decline organs based on their clinical judgement. There is a need for an objective method to assess organ quality before transplantation.

Method
Patient consent and demographics were noted prior to transplant surgery. Perfusion solution was flushed through donor livers or kidneys. FMN concentration was measured by fluorescence spectroscopy and cf mtDNA concentration was measured by digital droplet polymerase chain reaction. The concentrations of FMN and cf mtDNA were correlated with donor age & BMI and total length of recipient intensive treatment unit (ITU) stay.

Results
Amongst 8 transplanted livers, the study showed a negative trend between donor BMI and both FMN & cf mtDNA. There was a strong correlation between FMN concentration and ITU duration (r = 0.7353, p = 0.0376). Amongst 14 transplanted kidneys, MT-ND6 subunit concentration strongly correlated with donor BMI (r = 0.8473, p = 0.0003).

Conclusions
Despite more research being required to consolidate the role of these biomarkers, the study reinforces the idea that FMN and cf mtDNA can play a role as point of care tests in assessing organ quality prior to transplantation.
224 Surgical Repair of Mitral Valve Prolapse: Hypertension and Other Determinants of Failure
Authors: Ashbridge T , Briffa N , Ali A , Begum M 
Published: August 2023

Abstract

Aim
It has been postulated that hypertension is associated with an increased likelihood of repair failure in patients with mitral valve prolapse. This study aims to assess whether there is a significant association between hypertension and disease recurrence and need for reoperation.

Method
A retrospective observational cohort study was conducted at a single centre in the United Kingdom. Patients who underwent surgical repair for mitral valve prolapse were identified between January 2011 and December 2020, with follow-up data collected to December 2021. Patients were classified as hypertensive if they had a pre- operative clinic blood pressure of 140/90 mm Hg or above. Treatment failure was confirmed by the presence of moderate or worse regurgitation on post-operative echocardiography and/or need for reoperation. Multivariate logistic regression and Cox regression were used for statistical analysis.

Results
A total of 278 patients were identified who had pre-operative blood pressure data available, of those 144 were hypertensive. By the conclusion of the study period, treatment failure occurred in 11.5% of the study sample. No significant association was identified between the presence of hypertension and treatment failure, or time to treatment failure. Concomitant atrial ablation was, however, found to be protective against treatment failure (odds ratio, 6.1; 95% confidence interval, 1.2 to 32.8) and associated with longer time to treatment failure (hazard ratio, 6.3; 95% confidence interval, 1.6 to 25.1).

Conclusions
There is insufficient evidence to demonstrate that hypertension is associated with treatment failure or time to treatment failure for patients undergoing surgical repair for mitral valve prolapse.
655 Survival and Quality of Life Following CSF Diversion in Adult Patients with Leptomeningeal Metastases-Associated Hydrocephalus - a Systematic Review & Meta-Analysis
Authors: Dhaliwal J , Ruiz-Perez M , Mihaela-Vasilica A , Chari A , Hill C , Thorne L 
Published: August 2023

Abstract

Aim
Leptomeningeal Metastases (LM) is associated with altered CSF flow dynamics (50-70%), and 1-5% of patients will develop communicating hydrocephalus, adversely impacting quality of life (QoL), functional status, and overall survival (OS). There is equipoise for CSF diversion in LM-associated hydrocephalus (LM-H). This systematic review and meta-analysis aims to assess the effect of CSF diversion on OS and QoL in this context.

Method
This systematic review was conducted in accordance with PRISMA guidelines. Pubmed/MEDLINE, EMBASE, Web of Science, and Scopus were searched for articles evaluating the role of CSF diversion in adult patients with systemic cancer LM-H. A meta-analysis was conducted using random effects models, mean differences, and 95% confidence intervals (CI). Bias was assessed using the ROBINS-I tool.

Results
Ten eligible studies with a total of 494 patients were included. Two studies reported multivariate hazard ratios for median OS, suggesting no significant effect of shunting on OS (pooled HR = 0.42; p = 0.27; 95% CI 0.09-1.94). A pre-operative and post-operative Karnofsky Performance Status (KPS) mean difference of 17.6 points (CI 10.44-24.68; p&lt;0.0001) was calculated from 4 studies. Across all studies, a symptomatic improvement rate of 67-100% was observed, with high rates of improvement of headaches and nausea and lower rates for cranial nerve palsies. Complication rates across nine studies ranged from 0-21.1%.

Conclusions
The present findings prompt the generation of a standardised decision-making tool, a critical analysis of individual patient risk-benefit ratios, and systematic measurements for QoL for these patients. Implementation of these will facilitate and optimise surgical management for LM-H patients.
1188 The Effect of Bone Wax Application in Cardiac Surgery: A Systematic Review
Authors: Shah A , Kumar N , Raja S , Bhudia S 
Published: August 2023

Abstract

Aim
There is limited and conflicting evidence on whether bone wax usage in cardiac surgery increases infection risk. A systematic review was conducted to examine cardiac surgery postoperative outcomes following bone wax application.

Method
This systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The MEDLINE, EMBASE, and Scopus databases were searched for studies evaluating perioperative bone wax usage in the English language. All relevant synonyms of “Cardiac Surgery”, “Bone wax”, “Infection”, and “Healing” were used to identify papers. The outcomes of interest were wound infection, sternal dehiscence, postoperative sternal bleeding, postoperative chest drainage and mortality.

Results
From the 66 articles found, 5 were included following full-text screening. No statistically significant difference in infection risk between the bone wax (BW) and comparator groups existed. However, the evidence suggests bone wax significantly increases the risk of sternal dehiscence. Studies reporting postoperative bleeding showed a significantly greater mean volume in the BW group. All studies reporting postoperative chest drainage (n = 3) showed a greater mean volume in the BW group, of which two were significant. Of the three papers reporting mortality, two showed an increased risk in the BW group.

Conclusions
Current evidence indicates no significant association between bone wax and wound infection. Bone wax is associated with a greater risk of sternal dehiscence, postoperative sternal bleeding, postoperative chest drainage and mortality. Greater emphasis should be placed on bone wax alternatives in clinical practice. Limited data necessitates larger studies, and for clearer guidelines to be established around them.