bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal nonreciprocity tuned by wrinkle patterns in graphene
Authors: Li Bohan , Ji Qingxiang , Zhang Qi , Wang Changguo , Kadic Muamer
Published: November 2024

Thermal nonreciprocity are typically realized by using nonlinear heat conductivity, external field bias or spatiotemporal modulation of thermal parameters, but these methods require specific material properties or accurate modulation means. Low-dimensional materials like graphene provides a platform to engineer heat transport characteristics at the molecular level. Here, by simply tuning graphene’s wrinkle morphology, the approach to generate nonreciprocal heat transfer is reported, which applies to both static and dynamic heat signals. Such nonreciprocity is attributed to the tunable responses of thermal conductivity on both temperatures and wrinkles. Phonon density of states of the wrinkled graphene exhibit distinct spectra, especially at the low frequency (around

17
 

THz

), which results in reduced temperature-sensitivity of thermal conductivities and eventually induces thermal nonreciprocity. The findings provide insights into the physics of thermal transport in wrinkled graphene, and paves a new avenue for mechanically modulating thermal nonreciprocity. Our method to obtain thermal nonreciprocity is reversible, tunable and controllable, meanwhile remains structural integrity, which benefits functional applications such as heat management in electronics.
Design analysis and experimental verification of insulation blankets for civil aircraft nacelle and pylon
Authors: Gong Xingyu , Guo Junxian , Zhao Fei , Peng Sen
Published: November 2024

The nacelle and pylon structures of civil aircraft, due to their proximity to the engine, are significantly affected by the high-temperature components of the engine. To reduce the impact of high temperatures on the nacelle and pylon structures and their internal systems, insulation blankets are typically arranged on the inner side of the nacelle fan cowl, the inner side of the core cowl, and the bottom area of the pylon to decrease the thermal transfer effect from the high-temperature components of the engine and the hot air inside the core compartment to the nacelle and pylon structure. This paper mainly describes the structural design method and requirements for the nacelle pylon insulation blanket, and through thermal analysis theoretical calculations, the temperature changes on the cold side of the insulation blanket at different hot sides are derived. The results are compared with the insulation test results of the insulation blanket test pieces, further verifying the insulating performance of the blanket. In addition, environmental qualification tests were conducted on the insulation blanket test pieces, and insulation tests were re-performed on the test pieces after environmental testing, demonstrating the reliability of the nacelle and pylon insulation blanket design.
Characterization and evaluation of gold mill tailings as an additive in cement-stabilized products
Authors: Balbin A , Tabañag I D , Lavapiez M , Balanay R , Varela R , Omping H , McCarthy K H , Mutia M , Alvarado M R , Mirasol I J , Jabien J , Allih Tawantawan B
Published: November 2024

Gold mill tailings (GMT) are waste from gold mill processing plants usually collected and stored in tailings storage facilities (TSF) and left for years in many abandoned mines in the world. GMT is in large amounts and contains high concentrations of chemicals and compounds that may harm human lives and the ecosystem if not well-maintained. A characterization study is conducted on GMT from a small-scale mill processing plant in Agusan del Sur, Philippines, and its potential utilization as an additive to sand and cement in making cement-stabilized products is also evaluated. The elemental and oxide composition, the presence of free and total cyanide, and particle size analysis were determined. Different proportions of gold mill tailings, cement, and sand were prepared and tested for compressive strength and water absorption. The results showed that the GMT contained some potentially valuable elements like tin, zinc, and europium. GMT also contains potentially hazardous elements like lead (663ppm), arsenic (157ppm), and mercury (17ppm). The free cyanide in the effluent is also found at 1.9 ppm. These elements and compounds are potentially hazardous in case of tailings seepage or overflow to groundwater and neighboring agricultural lands. The evaluation of cement-stabilized samples shows that the GMT from the study area can be utilized as an additive to cement and sand in the production of cement-stabilized products however it must be properly treated and handled to ensure the safety of workers. The TCLP result showed that the product is non-toxic and non-reactive. The construction and proper maintenance of a TSF for small-scale gold milling plants in the study area is recommended to prevent environmental, health, and safety risks.
Production of nitrogen-free syngas (H2 + CO) from CO2 and NH3
Authors: Keller Martin
Published: November 2024

Towards the goal of carbon neutrality, future chemical production could utilize captured CO2 as a carbon source instead of fossil carbon from petroleum or natural gas. However, the production of chemicals from CO2 is highly energy-intense. The required energy could be imported to Japan in the form of hydrogen. However, the long-distance transport of molecular hydrogen is challenging. NH3 has recently emerged as the most promising molecule for long-distance hydrogen transport and storage. The use of imported NH3 as an energy vector to realize carbon recycling in the Japanese chemical industry is promising. Syngas (H2+CO) is an important intermediate in the production of chemicals and fuels from CO2. Hydrogen is required not only as a constituent of syngas, but also as a reductant of CO2. If hydrogen is imported in the form of NH3, conventionally, NH3 would be cracked to H2 and N2, the product gases and unconverted NH3 separated, and CO/syngas then be produced through the reverse water gas shift reaction (RWGS). This conventional pathway is energy-intense and requires many unit operations. Here a novel process to produce nitrogen-free syngas directly, without producing molecular H2 first and without any dedicated gas separation steps is presented. This is realized by a using a metal oxide bed material that is active for catalytic cracking of NH3, as well as able to transport oxygen through a redox reaction in a newly designed process. This leads to an inherent separation of N2. This process, referred to herein as “NH3-RWGS” has the potential to decrease costs and increase efficiency of syngas production from CO2 and NH3.
Carbon Footprint and GHG Reduction Potential of Bioethanol Production in the Philippines
Authors: Demafelis R B. , Magadia B T. , Matanguihan AE D. , Mawili AA U.
Published: November 2024

As the Philippine bioethanol industry concluded its first decade, it is in due time to assess whether the objectives of the Biofuels Act of 2006 (Republic Act No. 9367) are being met. Specifically, the law aims to reduce the country’s dependence on oil importation, mitigate toxic and greenhouse gases (GHGs), and promote the use of biofuels from indigenous resources to boost the country’s rural economy, by mandating biofuels blending to fossil-based fuels for transport use. This study examined the contribution of seven bioethanol production systems to the country’s climate change mitigation efforts by assessing the environmental impacts, particularly the carbon footprint and GHG emission reduction potential of each bioethanol distillery through life cycle assessment (LCA). Results of the environmental impact assessment revealed that the weighted average carbon footprint of the seven bioethanol production systems is at 1,415.66 gCO2e L−1, which ranges from 287 to 1,726 gCO2e L−1, translating to an average GHG reduction potential of 47.54% or an average avoided GHG of 268,091.15 tons CO2e yr−1 for CY 2019-2020. With the environmental hotspots identified, recommendations were made to improve the distilleries’ carbon footprints, and a sensitivity analysis was conducted to quantify the benefits from the recommended strategies. By applying all strategies, the average GHG reduction potential of the seven bioethanol production systems can get as high as 85.63%, which can be translated to an average avoided GHG of 482,933.91 tons CO2e yr−1.
Production characteristics in initial pyrolysis of lignin based on reactive molecular dynamics simulations
Authors: Kameda R , Sakurai Y , Hiratsuka M , Kobayashi J
Published: November 2024

Carbonization, direct liquefaction, and gasification, which are based on pyrolysis reactions, have been proposed as efficient technologies for energy recovery from biomass resources. However, modeling pyrolysis reactions of biomass with complex molecular structures is challenging, and numerical analysis methods that consider product compositions have not yet been established. In this study, molecular dynamics simulations were performed using LAMMPS, with the force field parameterized using ReaxFF. A molecular model based on Adler softwood lignin was created. The atomic trajectories were analyzed to identify the products of the pyrolysis process, and changes over time in inorganic gas, organic gas (C1-C4), light tar (C5-C14), heavy tar (C15-C39), and char (C40+) during the initial pyrolysis of lignin were investigated. The distribution of compositions formed and the formation behavior of typical low-molecular-weight components (such as formaldehyde and methanol) and inorganic gases from lignin were evaluated. The characteristics of the products in the initial pyrolysis of lignin, as analyzed from the molecular dynamics simulations, were based on the functional groups in the molecular model of lignin. Furthermore, similarities with the product compositions identified in experiments were also confirmed.
Investigation of the influence of fluorine on metal elution from cathodic active material liberated from spent lithium-ion batteries with a focus on the underwater electrical pulse method
Authors: Kong Yanhui , Takaya Yutaro , Córdova-Udaeta Mauricio , Tokoro Chiharu
Published: November 2024

As a promising candidate to separate the cathode materials and aluminum foils, the underwater electrical pulse method is an environmentally friendly method that can effectively liberate cathodic active material in a very short time. However, performing the electric pulse separation in aqueous media may cause the release of fluoridated elements, which may come from fluoridated components formed during battery cycles or due to the remaining electrolyte within the cathode particles. Thus, the purpose of this work is to study the solution obtained after pulse discharge in terms of fluoridated entities, to understand their effect on the elution of active cathodic materials. Herein, to investigate the potential source of F and its possible effects on metal extraction, leaching experiments were conducted in the presence of different fluoride concentrations with a solid/liquid ratio of 0.5g/L under circumneutral pH conditions (pH range: 5.7-7.5) using a spent nickel-cobalt-manganese lithium battery sample liberated by N-Methyl pyrrolidone. The results show that the amounts of F ions in solution increased with leaching time, with a maximum value close to 2.34 ppm F obtained after 2 h. It is worth noting that the presence of fluoride-ion can promote the elution of aluminum, as a maximum concentration of 1.85 ppm Al was observed at 2 h in the presence of 40 ppm F, whereas only about 0.32 ppm Al was detected in the case of fluoride-free solutions. Consequently, our results demonstrated that the amounts of transition metals (Ni, Mn, and Co) released towards liquid changed very little irrespective of the concentrations of dissolved fluoride, suggesting that the released F ions do not affect metals elution.
Ionic Liquids and its Potential as a New Green Solvent for REE Extraction in Philippine Bauxite Residues
Authors: Campos Ivanna Raena V. , Gabo-Ratio Jillian Aira S. , Payot Betchaida D. , Balela Mary Donnabelle L.
Published: November 2024

Rare earth elements (REEs) have become necessary for high-technology applications. This has prompted an increase in demand for REE exploration, production, and extraction. Despite its name, REEs are fairly rich in the Earth’s crust. REEs are estimated to have a crustal abundance of 9.2 ppm relative to other elements in our crust. In the Philippines, deposits are found to give adequately high concentrations of REE, ranging from approximately 200 ppm to 600 ppm. Samar bauxite deposits especially had around 500 ppm REE. In line with the planned bauxite production in the Philippines, it is of interest to further uncover ways to maximize its recovery. One of the possible optimizations in its extraction is to utilize its residue. There have been a number of methods to extract REE in bauxite residues. The use of ionic liquids (IL) to recover REE in bauxite offers a possibility of an effective and environmentally safe recovery process. ILs are molten salts that have melting points below 100degC. They exhibit high electrochemical stability, non-flammability, non-volatility, and can be tailored to the desired application. Hence, they have been the topic of study for different research regarding REE extraction in bauxite residues. Herein, the potential of ILs as a green solvent for REE extraction in bauxite is reviewed for future use in the extractive metallurgy of bauxites in the Philippines.
Symplectic duality for topological recursion
Authors: Bychkov Boris , Dunin-Barkowski Petr , Kazarian Maxim , Shadrin Sergey
Published: November 2024

We consider weighted double Hurwitz numbers, with the weight given by arbitrary rational function times an exponent of the completed cycles. Both special singularities are arbitrary, with the lengths of cycles controlled by formal parameters (up to some maximal length on both sides), and on one side there are also distinguished cycles controlled by degrees of formal variables. In these variables the weighted double Hurwitz numbers are presented as coefficients of expansions of some differentials that we prove to satisfy topological recursion.

Our results partly resolve a conjecture that we made in [Comm. Math. Phys. 402 (2023), pp. 665–694] and are based on a system of new explicit functional relations for the more general

(
m
,
n
)

(m,n)

-correlation functions, which correspond to the case when there are distinguished cycles controlled by formal variables in both special singular fibers. These

(
m
,
n
)

(m,n)

-correlation functions are the main theme of this paper and the latter explicit functional relations are of independent interest for combinatorics of weighted double Hurwitz numbers. We also put our results in the context of what we call the “symplectic duality”, which is a generalization of the

x
−
y

x-y

duality, a phenomenon known in the theory of topological recursion.
Tingley’s problem for positive unit spheres of operator algebras and diametral relations
Authors: Leung Chi-Wai , Ng Chi-Keung , Wong Ngai-Ching
Published: November 2024

We answer, in the affirmative, Tingley’s problem for positive unit spheres of (complex) von Neumann algebras. More precisely, let

Λ
:

S

A

+

→

S

B

+

\Lambda : \mathrm {S}_{\mathcal {A}^+} \to \mathrm {S}_{\mathcal {B}^+}

be a bijection between the sets of positive norm-one elements of two von Neumann algebras

A

\mathcal {A}

and

B

\mathcal {B}

. We show that if

Λ
\Lambda

is an isometry, then it extends to a bijective complex linear Jordan

∗

^*

-isomorphism from

A

\mathcal {A}

onto

B

\mathcal {B}

. In the case in which

Λ
\Lambda

satisfies the weaker assumption of preserving pairs of points at diametrical distance, namely,
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-vertical-bar normal upper Lamda left-parenthesis a right-parenthesis minus normal upper Lamda left-parenthesis b right-parenthesis double-vertical-bar equals 1 if and only if double-vertical-bar a minus b double-vertical-bar equals 1 left-parenthesis a comma b element-of normal upper S Subscript script upper A Sub Superscript plus Subscript Baseline right-parenthesis comma">

‖
Λ
(
a
)
−
Λ
(
b
)
‖
=
1

if and only if

‖
a
−
b
‖
=
1

(
a
,
b
∈

S

A

+

)
,

\begin{equation*} \|\Lambda (a) - \Lambda (b)\| =1 \quad \text {if and only if} \quad \|a-b\| = 1 \quad (a,b\in \mathrm {S}_{\mathcal {A}^+}), \end{equation*}

one can still conclude that

A

\mathcal {A}

is complex linear Jordan

∗

^*

-isomorphic to

B

\mathcal {B}

.

On our way, we also show that if there is an order isomorphism

Θ
:

P

A

→

P

B

\Theta :\mathrm {P}_\mathcal {A}\to \mathrm {P}_\mathcal {B}

between the projection lattices of

A

\mathcal {A}

and

B

\mathcal {B}

that preserves pairs of points at diametrical distance, that is,
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-vertical-bar normal upper Theta left-parenthesis p right-parenthesis minus normal upper Theta left-parenthesis q right-parenthesis double-vertical-bar equals 1 if and only if double-vertical-bar p minus q double-vertical-bar equals 1 left-parenthesis p comma q element-of normal upper P Subscript script upper A Baseline right-parenthesis comma">

‖
Θ
(
p
)
−
Θ
(
q
)
‖
=
1

if and only if

‖
p
−
q
‖
=
1

(
p
,
q
∈

P

A

)
,

\begin{equation*} \|\Theta (p) - \Theta (q)\| =1 \quad \text {if and only if} \quad \|p-q\| = 1\quad (p,q\in \mathrm {P}_\mathcal {A}), \end{equation*}

then

A

\mathcal {A}

and

B

\mathcal {B}

are complex linear Jordan

∗

^*

-isomorphic. If, in addition, either

A

\mathcal {A}

has no type

I

2

\mathbf {I}_2

summand, or

Θ
\Theta

is an isometry, then

Θ
\Theta

extends to a complex linear Jordan

∗

^*

-isomorphism from

A

\mathcal {A}

onto

B

\mathcal {B}

.

Actually, the above results are proved in the slightly more general situation that

A

\mathcal {A}

and

B

\mathcal {B}

are

A

W
∗

AW^*

-algebras.
A01 - AHP An Examination of the Opinions of NHS Stakeholders on the Current and Future Role of Physician Associates
Authors: Abdeen Bashar , Millard Alice , Al Soudi Tareq , Issa Eyad , Isherwood John , Dennison Ashley , Garcea Giuseppe
Published: November 2024

Background

Globally, healthcare systems are experiencing problems recruiting and retaining healthcare workers. Like many developed countries, in the UK, shortages are exacerbated by rising healthcare costs and models have had to be developed utilising shorter training periods and a generalized skillset. One of the consequences is the development of intermediate-level practitioners including Physician Associates (PAs). By 2024 over 4,000 PAs were working in the NHS, but their myriad roles has meant that integration has been challenging. This study examines the opinions of NHS stakeholders on the current and future roles of PAs and explores approaches to improve their integration.

Method

This cross-sectional study at a single NHS Trust gathered views and experiences regarding PAs through a survey of consultant and junior medical staff (JDs), PAs, and patients. Patients who interacted with a PA within four weeks prior to the period of the survey were randomly selected to avoid recall bias. Surveys, initially generated by doctors and a PA, were tailored, validated by experts, and pilot-tested. Distribution was via Microsoft Forms® and ACCURX® and responses were collected electronically with weekly reminders. Data were analysed using Microsoft Excel® and SPSS®, with qualitative analysis used to identify recurring themes.

Results

Consultants more frequently recognised positive contributions of PAs (p=0.012) although 68.6% noted PA roles were unclear. The PA role had only been explained to 11% of JDs, just 14% fully understood their role and 75% felt PAs might negatively affect their training. Conversely most PAs felt consultants (87.5%) and JDs (81.3%) were aware of their responsibilities. While 62.5% of PAs anticipated career progression, 87.5% were satisfied with training, 56.3% were considering a career change and 75% felt the healthcare climate adversely affected their work. Only 14% of patients fully understood the PA role, but 86% comfortable being seen by them.

Conclusion

This study highlights the positive contributions of PAs and recognition by stakeholders. Integration however remains challenging with concerns regarding JD training, PA career progression, and job satisfaction. The main hurdles remain unclear compounded by myriad PA roles and surveys reveal significant gaps in understanding among JDs and patients. PAs overestimate understanding of their role and education of stakeholders regarding their PA roles is crucial and must involve PAs, managers, consultants, GMC, and Royal Colleges. Local trusts and consultants must define PA roles, ensure career progression, and support JD training to enhance interprofessional relationships, trust, and the quality of patient care.
A03 - BN Long Term Quality of Life Outcomes Following the Surgical Management of Complete Intrathoracic Stomach (CIS)
Authors: Pal Shreya , Divekar Omkaar , Oxenham Matthew , Pangeni Anang , Fernandes Roland , Basu Sanjoy
Published: November 2024

Background

Surgery is indicated for symptomatic patients with complete intrathoracic stomach (CIS) to avoid complications (volvulus, obstruction and strangulation) associated with high morbidity. There remains limited evidence of the long-term outcomes and improvement in symptoms from this procedure. Previous large studies have been unable to compare pre-operative symptoms with their post-operative data. Although it appears the procedure has favourable outcomes, further data is required to demonstrate a significant improvement in quality of life (QoL). We therefore aim to assess the long-term outcomes, including changes to QoL and satisfaction, for patients who underwent laparoscopic biological hiatal mesh reconstruction for CIS (100%).

Method

Prospective data was collected from 154 consecutive GPEH (Giant Hiatus Hernia) patients intervened between March 2008- December 2023 in a large DGH. Retrospective analysis of this identified a subgroup of 34 patients with CIS. All patients underwent a laparoscopic repair with biological mesh, apart from one patient who underwent gastropexy.

Outcome measures included both pre-operative and post-operative standardised GERD-Health Related Quality of Life Questionnaire (GERD-QOL) scores; complications; and patient satisfaction.

Results

Thirty-four patients were included (11 male:23 female) with a mean age 72 (45-83) years. All patients were symptomatic pre-operatively with heartburn (59%), dysphagia (59%), retrosternal discomfort (53%), vomiting (41%), weight loss (41%) or shortness of breath (35%). There were 4 (12%) complications and 3 (9%) 30-day mortalities. Follow up GERD-QOL questionnaires displayed 32/34 (94%) excellent scores (defined as total <5) at 6 months and 15/21 (71%) excellent scores after a median follow up of 8.5 years (72% response rate, 2 further mortalities). This demonstrated a significant improvement in scores following the procedure and long term (p<0.001). Nineteen patients (90%) were satisfied with the procedure after long term follow up (median 8.5 years).

Conclusion

Laparoscopic repair of complete intrathoracic stomach in this large single-centre study has demonstrated a significant improvement in symptoms and satisfaction over a median 8.5 year follow-up.
OGC O01 - Stomach Cancer Elective Surgery Morbidity and Mortality at 90-Days (HOLD Study): A Prospective, International Collaborative Cohort Study
Authors: Neves-Marques Claudia , Abouelazayem Mohamed , Gupte Anaya , Mun Wong Geoffrey Yuet , Vish Y K S , Boddy Alex , Donohue Claire , Maldonado Ricardo David , Scarano Juan Pablo , Martinino Alessandro , Aamery Amaar
Published: November 2024

Background

Data on multinational 90-day mortality and morbidity rates after surgery for gastric cancer is limited in the literature. This study aimed to understand the 90-day mortality and morbidity outcomes according to GASTRODATA Registry for elective gastric cancer surgery patients and identify risk factors.

Method

We conducted an international prospective study on ≥18 years patients undergoing elective surgery for gastric cancer with curative intent from 01 April 2022 to 30 September 2022. Known metastatic disease, concurrent secondary cancers, gastrointestinal stromal tumour (GIST) and Siewert type I/II oesophagogastric junction malignancies were excluded. Univariate and multivariate logistic regression was used to identify variables associated to 90-day outcome.

Results

380 collaborators from 47 countries submitted data on 1538 patients. Mean age was 64.2 years and 58.5% were males. 90-day morbidity rate was 38.2% (n=587) and mortality rate was 2.9% (n=45).

Pre-operative higher CCI or ASA score, pre-operative weight loss >10%, and surgical determinants such as type of gastric resection, positive specimen margin, number of harvested lymph nodes, longer surgery duration and post operative pathological IV staging (p value<0.05) were identified as predictors of postoperative severe complications and mortality.

Conclusion

Elective gastric cancer surgery has a 90-day morbidity of 38.2% and 90-day mortality of 2.9%, globally. This study identified several factors associated with higher morbidity and exemplified the importance of a unified language on surgical morbidity, pre-habilitation and ongoing audits to enhance patient outcomes.
OGC O05 - Utilising patient derived organoids to predict the response to treatment in gastric cancer
Authors: Alam Mushfique , Duckworth Carrie , Howes Nathan , Stephens Nathan , Pritchard Mark
Published: November 2024

Background

Gastric adenocarcinoma remains a significant global health burden. For advanced disease, treatment remains multi-modal with neoadjuvant chemotherapy followed by resectional surgery. Although the FLOT4-AIO trial has established the regimen of 5-fluorauracil, Leucovorin, Oxaliplatin and Docetaxel (FLOT) as the gold standard, some patients demonstrate a poor or no response to treatment, resulting in adverse oncological outcomes. Currently there are no accurate biomarkers to assess or predict the treatment response to neoadjuvant therapy. This study aims to explore the potential of patient-derived organoids as a predictive model to assess the treatment response to neoadjuvant chemotherapy in gastric adenocarcinoma.

Method

Patient derived organoids are a novel, 3 dimensional in-vitro model which recapitulates the different cells that constitute the tissue of origin. From June 2023 to June 2024, 25 patients with a confirmed diagnosis of gastric adenocarcinoma, were recruited for tissue acquisition for organoid generation. Endoscopic biopsies of cancer tissue taken during OGD and staging laparoscopy were used to generate organoids from each patient. Organoids were subsequently expanded to a sufficient volume to allow cytotoxicity assays in response to different doses of the FLOT regimen. The organoid cytotoxicity response was compared to the patients radiological and pathological response following treatment.

Results

Organoids were successfully generated from 76% of recruited patients (n=19). Of these, 4 patients and were excluded due to being unfit for neoadjuvant chemotherapy, whilst 2 were excluded due to the confirmation of metastatic disease, precluding neoadjuvant treatment. Finally a single patient was excluded due to mortality during neoadjuvant treatment. Of the remaining organoids, 5 were subjected to FLOT treatment within 2 weeks of tissue acquisition. Organoids demonstrated unique dose response profiles following with statistically significant differences in the IC50 values (p =0.048). The organoid responses corresponded to the clinical responses demonstrated by the patient they were derived from.

Conclusion

In conclusion, this study underscores the potential of patient-derived cancer organoids as a predictive model for assessing the response to neoadjuvant chemotherapy in gastric adenocarcinoma. The generation of organoids from a significant proportion of patients and the subsequent drug response testing within 2 weeks of tissue acquisition suggests this novel method has the potential to become a valuable tool for predicting patient-specific responses and guiding personalised treatment plans. As such, further research is warranted to further assess the validity of this model, refine the existing techniques and explore its potential integration into clinical practice.
HPB O01 - Colonization of bile with gammaproteobacteria reduces survival after surgery for pancreatic cancer in patients receiving gemcitabine-based adjuvant chemotherapy
Authors: Terry Charlotte , Halle-Smith James , Sutcliffe Robert , Marudanayagam Ravi , Chatzizacharias Nikolaos , Dasari Bobby , Bartlett David , Raza Syed , Roberts Keith
Published: November 2024

Background

Evidence suggests that the biliary microbiome influences the progression of pancreatic ductal adenocarcinoma (PDAC) in patients undergoing adjuvant chemotherapy. Specifically, Gammaproteobacteria (GPB) has been shown to have the potential to develop mutations which can metabolise gemcitabine into an inactive form. This study hypothesised that GPB influences survival in patients with PDAC undergoing adjuvant gemcitabine-based chemotherapy following surgery.

Method

This was a retrospective study of patients undergoing pancreatoduodenectomy from 2010 to 2020. Associations between patient and tumour characteristics, survival data, and results of intraoperative bile cultures (GPB+ or GPB-) were investigated. Analysis of patients matched by chemotherapy regimen and numbers of cycles of adjuvant therapy was also performed. Survival was analysed using Kaplan–Meier curves and Cox regression analysis.

Results

Analysis of 359 patients revealed that adjuvant gemcitabine-based therapy improved overall survival (OS). Patients who receive gemcitabine-based chemotherapy with a GPB+ biliary culture had a shorter OS compared to those who were GPB-, and a median survival of 17.9 vs 26.1 months, P=0.006. After matching for key chemotherapy variables, survival was greater in the GPB- group 26.8 vs 19.8, P=0.016. This association was not seen among patients who received no adjuvant therapy or non-gemcitabine based therapy.

Conclusion

Patients receiving gemcitabine-based chemotherapy after surgery are likely to have reduction in OS if they have a biliary culture positive for GPB.
HPB O04 - Human Splenic Ex-Vivo Perfusion Model: A Platform for Translational Basic Science Research
Authors: saoudi Tareq Al , Alnabati Neama , Chung WenYuan , Schilcher Katrin , Robertson Francis , Issa Eyad , Isherwood John , Malde Deep , Garcea Giuseppe , Oggioni Marco R , Dennison Ashley
Published: November 2024

Background

The function of the spleen has always been shrouded in mystery and since the Renaissance leading figures have attempted to understand its function. Vesalius questioned Galen and Marcello Malpighi (1628-1694) gave the first accurate description of the histology and the physiology. The spleen still poses unique challenges as invasive approaches may produce intraperitoneal bleeding, differences between human and animal spleens complicates comparative studies, and post-mortem examinations reveal only late-stage disease manifestations and functional studies are impossible. This study describes a human splenic ex-vivo perfusion model for translational research, using microbiological studies as markers of splenic physiological function.

Method

Patients with left-sided pancreatic cancers scheduled for distal pancreatic and splenic resection were identified from the Hepato-Pancreatic and Biliary MDT at the University Hospitals of Leicester NHS Trust. Patients were informed, consented, and the surgical approach remained standard, with splenic artery ligation deferred until specimen extraction. The artery was cannulated, and residual blood clots were cleared with Custodiol® HTK solution. The perfusion technique employs an extracorporeal circuit incorporateing anoxygenator and a heated water chamber maintaining a 37°C perfusate. The perfused spleen was infected with Streptococcus Pneumoniae strains, with regular biopsies and perfusate gas analysis performed.

Results

Since February 2023, nine spleens have been successfully perfused, with an average weight of 169.5 grams, cold ischemic time of 116 minutes, and warm ischemic time of 12.2 minutes. Pressure was maintained at 80 mmHg and hourly perfusate gas analysis demonstrated a mean pH of 7.1 and a gradual increase in lactate. Histopathological examination revealed clear distinctions between the lymphoid tissue and splenic red pulp, with intact central arterioles and healthy cell morphology at time 0 and after 6 hours of perfusion. Additionally, the perfused spleens cleared S. pneumoniae strains to below-detection levels.

Conclusion

Our work demonstrates that a stable human splenic ex-vivoperfusion model which maintains structural and physiological integrity can be achieved from tissue that would otherwise be discarded. The continued physiological function is confirmed by the clearance of S. pneumoniae. While currently employed for microbiological studies, this model has the potential to facilitate a wide range of different translational science studieswhile reducing the need for animal experimentation. The perfusion times employed for the present study were sufficient to demonstrate bacterial clearance which was the aim but there is capacity in the system to significantly prolong the duration.
MS O06 - HPB The ORDEAL Study: A National Survey of Surgeon Operative Preferences for Resection of Duodenal Adenocarcinoma
Authors: Kowsik Mukunth , Horne Sophie , Pandé Rupaly , Chatzizacharias Nikolaos
Published: November 2024

Background

Duodenal adenocarcinoma (DA) accounts for over 50% of all small bowel adenocarcinomas, however there is a paucity of data on outcomes, no UK guidelines for surgical management, and current national standards of practice are unknown. There is ongoing debate whether long-term survival, perioperative outcomes, resection margin, and lymph node yield differ between pylorus-preserving pancreaticoduodenectomy (PPPD) and classical PD (cPD) in proximal DA (D1/D2), and between PD and limited resection (LR) in distal DA (D3/D4). The study aimed to discern current standards of practice and identify underlying reasons for operative preferences for proximal and distal DA.

Method

An anonymised survey was included as part of the registration form for a wider multicentre retrospective study looking at outcomes following resection for proximal and distal DA on Google Forms®. The survey was distributed via direct surgeon email correspondence, weekly newsletters and surgical society endorsement by PSGBI. Responses were collected between February-June 2024 and responses were analysed with quantitative and qualitative (inductive thematic analysis) methods.

Results

Responses were received from 61 surgeons across 27 centres. For proximal DA, surgeons are more likely to consider a classical Whipple’s (93.4%) compared to PPPD (29.5%). For distal DA, surgeons are equally likely to consider LR (73.8%) as PD (classical Whipple’s -37.7%, PPPD - 41%). These preferences have mostly remained consistent over time. Key themes identified from thematic analysis included oncological considerations, morbidity, surgeon preference, tumour characteristics, standards of practice, patient factors and anatomical considerations, with the former two themes being the most prominent.

Conclusion

For proximal DA, cPD is preferred over PPPD and for distal DA, LR and PD are equally considered, with oncological and morbidity considerations largely influencing decision making. This qualitative data will be compared to actual practice following completion of the wider ORDEAL study to identify discrepancies in practice and possible effect on patient outcomes.
MS O07 - OGC ‘Textbook Outcome’ for Gastrectomy: Redefining a Valid Composite Measure Assessment Tool for Surgical Performance in a Specialist Unit within the United Kingdom
Authors: Gan Tze Yi , Brown Leo R , McGregor Richard J
Published: November 2024

Background

A ten-item composite measure defining ‘textbook outcome’ (TBO) following oesophagogastric cancer surgery was proposed to benchmark surgical quality. While subsequent studies have demonstrated an association between TBO and improved survival, the reported proportion of patients who meet all the required criteria remained consistently low. Postoperative complications of Clavien-Dindo grade ≥2 (CD≥2) commonly preclude TBO, despite evidence that minor complications are unlikely to influence long-term outcomes. This study aimed to assess whether modification of TBO parameters to Clavien-Dindo grade ≥3 (CD≥3) is associated with improved overall survival in patients undergoing gastric cancer surgery within an UK specialist unit.

Method

Consecutive patients who underwent a surgical resection for gastric cancer, at a single tertiary centre between January 2016 and December 2019, were identified from a prospectively maintained regional database. Patients were included irrespective of (neo)adjuvant treatments. Data collected included clinicopathological characteristics, treatment modalities and postoperative outcomes. Comparisons were drawn between patients who met all the parameters defining TBO and those who did not, using both CD≥2 and CD≥3 classifications for ‘major’ complications. The primary outcome of interest was overall survival.

Results

Sixty-seven patients (median 70 years, 61.2% male) underwent resection for gastric cancer during this study. Of these, 27 patients (40.3%) achieved TBO based on a CD≥2 complication grading and 38 patients (56.7%) when CD≥3 was used. Clinicopathological characteristics were all comparable between TBO groups based on both cut-offs. Improved overall survival was evident with a CD≥3 TBO (p=0.026), however not with CD≥2 TBO (p=0.430). Following adjustment for confounding variables, CD≥3 TBO remained associated with improved overall survival (HR: 0.30 (95% CI: 0.10-0.93), p=0.037) while CD≥2 TBO was not (HR: 0.64 (95% CI: 0.21-1.93), p=0.428).

Conclusion

Textbook outcome is a multi-parameter metric for benchmarking quality in gastric cancer surgery. Modification of the complications parameter required for TBO to CD≥3 in our patient population resulted in a stronger association with overall survival amongst patients undergoing surgical resection for gastric cancer.
AHP SO09 - Introduction of Registered Advanced Nurse Practitioner into Upper Gastrointestinal Cancer Surgical Service
Authors: Hickey Wendy
Published: November 2024

Background

The author whom is a nurse, works in a large University teaching hospital with a mission to deliver best quality care to patients, where its nursing philosophy ensures continued and consistent commitment in the provision of holistic patient centred care to the highest possible standard. The introduction of the new Registered Advanced Nurse Practitioner (RANP) role within the Upper GI Surgical Department is part of the expansion of the Upper Gastrointestinal cancer service within the hospital.

Method

At the nurse-led cancer surveillance clinic the RANP is authorised to assess, review and initiate diagnostic interventions for a specific agreed cohort of patients with Upper GI cancer.

Results

An Upper GI RANP has recently been recruited into the Upper Gastrointestinal cancer surgical service in the hospital and commenced reviewing patients on 11.09.23. The overall aim of the post is to deliver an advanced level of clinical nursing practice within the field of gastrointestinal cancer with the quality improvement objective to enhance patient experience within the hospitals Upper GI cancer service.

Conclusion

Cancer survivorship begins at the time of diagnosis and continues until the end of life (DOH; 2017). Optimising these patients’ quality of life is now a primary focus of the Irish Healthcare system. Focus has now shifted to living well with, through and beyond a cancer diagnosis (DOH; 2017).

The National Cancer Strategy 2017- 2026 (DOH;2017) has highlighted that there is significant scope and need to expand the number of ANP’s in our cancer services particularly to run nurse-led clinics for follow-up and survivorship. This new ANP role within the Upper GI service will seek to address this need.
EDI&S SO06 Do All Patients with Biliary Problems Need Surgery? Applying C-Gall Study Results to Long Waiters for Laparoscopic Cholecystectomy
Authors: Mahendran Ashuvini , Hollyman Marianne
Published: November 2024

Background

The recent C-GALL study, a multi-centre randomised trial, found no significant difference in quality of life at two years between operative and non-operative management of uncomplicated gallstone disease.

This suggests some patients may not benefit from elective laparoscopic cholecystectomy (LC), potentially leading to over-listing for surgery. By identifying patients who may no longer need surgery, we could reduce waiting lists and improve resource allocation.

This study aims to reassess patients with an enforced period of observation on an elective waiting list for LC, to determine if they wish to make a different decision about proceeding with surgery.

Method

Patients listed for an elective LC who had been waiting longer than 11 months from referral were reviewed. Patients were contacted through telephone clinics by a surgeon. Data was collected on type of gallstone disease, history of abdominal surgery, biliary pain since last seen by a clinician, pain radiation to the back, pain reduction with simple analgesia, nausea, and heartburn. Identified patients were contacted and, if exhibiting minimal or no symptoms, were offered the option to be removed from the waiting list with 12 months of patient-initiated follow-up and high priority relisting if their clinical condition worsened.

Results

We contacted 59 patients awaiting elective LC Most were female (49, 83%), had biliary colic (43, 73%), and were under 60 years old (38, 64%).

Seventeen patients (29%) were happy to opt out due to lack of symptoms. Of these, 13 (76%) were female, 11 (65%) had biliary colic, and 7 (41%) were under 60.

Chi-squared analysis identified age as the only predictive factor, with those under 60 being less likely to opt out (p=0.038).

We will continue to monitor representation and the need for reoperation to ensure safety and the findings remain consistent overtime.

Conclusion

The study demonstrates that a significant proportion of patients awaiting elective LC can be safely managed without planned cholecystectomy, potentially reducing waiting lists, cost and utilisation of healthcare resources. We would advise considering review of long waiters to re-evaluate their clinical need for cholecystectomy in order to improve sustainability within surgery. These findings support a more personalised approach to managing biliary pain, prioritising patients for surgery based on symptom severity.
EDI&S SO09 Tracking Waste in Surgical Theatres (TWIST) - a snapshot of waste production in a large teaching hospital
Authors: Yao Lu , Amar Hoda , Aroori Somaiah
Published: November 2024

Background

The NHS contributes up to 5% of the UK’s greenhouse gas emissions. Thirty percent is generated by operating theatres, of which a significant proportion comes from single-use consumables. The aim of this project was to evaluate the amount and cost of disposable material that was opened but unused in theatres. By identifying areas for improvement, this can help to reduce the environmental impact of our work.

Method

This was a trainee lead collaborative study taking place over a period of two weeks at a tertiary teaching hospital, between Monday 19th and Friday 30th June. We prospectively collected information on the number of consumables that were opened but unused across various surgical specialties. The number and type of materials wasted at the end of each list were recorded and a cost analysis performed. A questionnaire was sent to staff to assess factors influencing theatre waste.

Results

A total of 238 operating lists were covered during the study period. A total of 636 procedures took place, and 544 items were wasted, coming to a cost of £1993.56. The mean number of items wasted per list was 2.3 and the mean cost per list was £8.38. The most common item wasted was sutures. The most common factors staff felt contributed to waste production were the surgeon’s preferences and lack of experience among staff.

Conclusion

Unnecessary waste production in theatres has significant environmental and financial consequences. We can hope to reduce this by educating staff, including surgeons and the wider theatre team.
BS SO05 - A Comparative Study Between Laparoscopic Sleeve Gastrectomy with omentopexy Versus conventional Laparoscopic Sleeve Gastrectomy: A Prospective Cohort Study
Authors: Hassan Basma , Awad Philobater
Published: November 2024

Background

Sleeve Gastrectomy, is a widely used procedure globally. However, omentopexy is a newly added variation, which involves reattachment of the omental to the stomach. Currently, there is not enough data regarding this technique

Method

A prospective cohort study, was conducted from June 2021 to June 2023 in University Hospitals and other non-governmental hospitals, which included 174 for a one-year follow-up.

Results

Group (I) with omentopexy while Group (II) without omentopexy. Regarding intra-operative time, the mean time in minutes in the group (I) is 115.45 minutes with a standard deviation ±11.19. While in group (II) is 79.8 minutes with a standard deviation of ±13.3 (p=O.001). Regarding complications rate . leakage occurred in 1(1.14%) patient in group (I). While, in 3(3.4%) patients in group (II) (p=0.62). Bleeding was found in 1 (1.1%) patient in group(I) and 2(2.3%) patients in group (II) (p=1). GERD was found in 10(11.49%) patients in group(I) and 12(13.7%) patients in group (II) (p=0.82).

Conclusion

Although there was no significant superiority in the group of patients with omentopexy, less bleeding, leakage, and GERD were detected compared to the traditional group, so we recommend further studies comparing both groups to be able to do meta-analysis comparing both groups and we also should emphasize that further refinement of the learning curve is possible in the future to further reduce the operative time required to execute this essential technique.