bluuebunny/crossref_metadata_2025 huggingface dataset:
Constructing keyed strong S-Box with optimized nonlinearity using nondegenerate 2D hyper chaotic map
Authors: Kadeer Abudureheman , Tuersun Yilihamu , Liu Hongjun
Published: November 2024

In the realm of information security, the nonlinearity of an S-Box is a pivotal attribute for ensuring its effectiveness. S-Boxes randomly generated with chaotic maps, however, often exhibit insufficient nonlinearity. To construct a robust S-Box with enhanced nonlinearity, we have developed a nondegenerate two-dimensional hyper chaotic map (2D-NDHCM). We rigorously evaluated its dynamic properties through bifurcation and phase diagrams, Lyapunov exponents, Kolmogorov entropy, correlation dimension, and randomness tests to assess the map’s resilience. Subsequently, we employed the 2D-NDHCM to devise a novel algorithm for constructing and optimizing a keyed strong S-Box, leveraging simulated annealing technique to achieve superior nonlinearity. Finally, We conducted performance analyses of the optimized S-Box using the classic six criteria, and the results confirmed the algorithm’s practicality and effectiveness.
Nonlinear multi-image optical authentication based on QR decomposition and Kramer-Kronig relations
Authors: Vardhan Harsh , Sivarajan Aswathi K , Shrivastav Anand M , Reddy Salla Gangi , Kumar Ravi
Published: November 2024

In this paper, a new nonlinear optical multi-image authentication scheme is proposed based on Kramers-Kronig digital holography and orthogonal triangular decomposition or QR decomposition. Here, the complex light field carrying the information of multiple images is modulated by random phase masks and propagated at certain distance. Afterwards, the QR decomposition is applied to the complex wavefront to generate the private keys and to add the non-linearity in the scheme. Next, the product of orthogonal matrix and upper triangular matrix is processed further. The obtained output is modulated by different phase masks and interfered with reference beam to record the encrypted image. For decryption, the Kramer-Kronig relation is utilized to extract the plaintext images directly with only the positive frequency part. A series of numerical simulations are conducted to validate the efficacy and robustness of proposed image authentication scheme.
The energy dispersion of magnetic Rossby waves in the quasi-geostrophic shallow water magnetohydrodynamic theory
Authors: Yang Yi , Li ChengKang , Jiang PeiYa , Li YaoKun
Published: November 2024

This research firstly comprehensively investigates the energy dispersion of magnetic Rossby waves in zonally non-uniform basic states by applying the quasi-geostrophic (QG) shallow water magnetohydrodynamic (SWMHD) equations. The eddy momentum and heat flux transported by magnetic Rossby waves, which can be described by the group velocity vector, have significant impacts on the large-scale dynamics of various celestial bodies. The findings suggest that the energy dispersion paths, also called rays, are curves and restricted in limited regions in the non-uniform basic states, in contrast with straight lines in the uniform basic states. Furthermore, the limited propagative regions are influenced by three important meridional locations, which are defined as the symmetric turning location, the asymmetric turning location, and the critical location. The first two reflect rays and the third one acts as an asymptote. The propagative region that is enclosed by a turning location and a critical location is more general. Besides, the occurrence of the asymmetric turning location, which is mainly depended on the distribution of the zonal basic flow, is a quite new feature of the energy dispersion for magnetic Rossby waves since there is no asymmetric turning location for Rossby waves on the Earth’s atmosphere and ocean. The results have important applications in illustrating interactions between magnetic Rossby waves and zonally basic states and in explaining the maintenance of the zonal flow and meridional circulation of various celestial bodies.
Rotating nonlinear states in trapped binary Bose–Einstein condensates under the action of the spin–orbit coupling
Authors: Sakaguchi Hidetsugu , Malomed Boris A
Published: November 2024

We report results of systematic analysis of confined steadily rotating patterns in the two-component BEC including the spin–orbit coupling (SOC) of the Rashba type, which acts in the interplay with the attractive or repulsive intra-component and inter-component nonlinear interactions and confining potential. The analysis is based on the system of the Gross–Pitaevskii equations (GPEs) written in the rotating coordinates. The resulting GPE system includes effective Zeeman splitting. In the case of the attractive nonlinearity, the analysis, performed by means of the imaginary-time simulations, produces deformation of the known two-dimensional SOC solitons (semi-vortices and mixed-modes). Essentially novel findings are reported in the case of the repulsive nonlinearity. They demonstrate patterns arranged as chains of unitary vortices which, at smaller values of the rotation velocity Ω, assume the straight (single-string) form. At larger Ω, the straight chains become unstable, being spontaneously replaced by a trilete star-shaped array of vortices. At still larger values of Ω, the trilete pattern rebuilds itself into a star-shaped one formed of five and, then, seven strings. The transitions between the different patterns are accounted for by comparison of their energy. It is shown that the straight chains of vortices, which form the star-shaped structures, are aligned with boundaries between domains populated by plane waves with different wave vectors. A transition from an axisymmetric higher-order (multiple) vortex state to the trilete pattern is investigated too.
Morphology and structural properties of thin rubrene crystallites grown on graphite
Authors: Naeimi Moha , Engster Katharina , Barke Ingo , Speller Sylvia
Published: November 2024

Crystallization of rubrene, progressing from an amorphous phase to a triclinic meta-stable and ultimately to the orthorhombic stable phase, offers broad applications not only in organic electronic devices but also for in-depth studies of optical and electronic properties, including exciton distribution and dynamics. We investigate the crystallization of rubrene on highly oriented pyrolytic graphite (HOPG), aiming at the growth of the preferred rubrene orthorhombic phase, which has been reported to have one of the highest charge mobilities in organic semiconductors. This is achieved through controlled heating and enhanced partial pressure. Through precise control of the initial deposition on the substrate, we investigate the growth habit of rubrene crystals by high-rate heat treatment beyond the second crystallization temperature. Furthermore, this work addresses thermal stability and photodegradation across various morphologies.
Interfaces of the two-dimensional voter model in the context of SLE
Authors: Godrèche Claude , Picco Marco
Published: November 2024

This paper investigates various geometrical properties of interfaces of the two-dimensional voter model. Despite its simplicity, the model exhibits dual characteristics, resembling both a critical system with long-range correlations, while also showing a tendency towards order similar to the Ising–Glauber model at zero temperature. This duality is reflected in the geometrical properties of its interfaces, which are examined here from the perspective of Schramm–Loewner evolution. Recent studies have delved into the geometrical properties of these interfaces within different lattice geometries and boundary conditions. We revisit these findings, focusing on a system within a box of linear size L with Dobrushin boundary conditions, where values of the spins are fixed to either +1 or −1 on two distinct halves of the boundary, in order to enforce the presence of a pinned interface with fixed endpoints (or chordal interface). We also expand the study to compare the geometrical properties of the interfaces of the voter model with those of the critical Ising model and other related models. Scaling arguments and numerical studies suggest that, while locally the chordal interface of the voter model has fractal dimension

d
f

=
3

/

2

, corresponding to a parameter κ = 4, it becomes straight at large scales, confirming a conjecture made by Holmes et al (2015 J. Stat. Phys.
159 937–57), and ruling out the possibility of describing the chordal interface of the voter model by SLE

κ

, for any non-zero value of κ. This contrasts with the critical Ising model, which is described by SLE3, and whose interface fluctuations remain of order L, and more generally with related critical models, which are in the same universality class.
Collaborative Seismic Impedance Inversion under Bayesian Parameter Estimation
Authors: Ren Lilong , Yan Jianguo , Pranto M. R , Huang Wenlu , Xie Rui
Published: November 2024

At present, the industry mainly divides seismic inversion methods into deterministic inversion and deterministic inversion based on the methods and principles used in inversion. There are two types of geostatistical inversion. Deterministic inversion is the process of directly modifying the model quantity through optimization algorithms under given initial constraint conditions to obtain a definite solution; Geostatistical inversion uses random simulation methods to obtain inversion results through simulation and selection. The seismic data did not participate in the direct modification of the model, but rather served as a matching optimization constraint for the random model. Starting from the Bayesian formula, this article unifies deterministic inversion and geostatistical inversion within the Bayesian parameter estimation framework. From a theoretical framework, it analyzes the similarities and differences between deterministic inversion and geostatistical inversion, and proposes a method that combines deterministic inversion and geostatistical inversion - seismic wave impedance co inversion. Sequential Gaussian simulation and model constrained inversion are used as examples of the two major methods, The correctness of the research results and the feasibility and effectiveness of the proposed new inversion method and process have been verified through the application of the Marmousi theoretical model and actual data from Fudong, Fukang Depression, Xinjiang. It has been proven that the proposed method can improve the accuracy and precision of inversion. The inversion method and process used in this study obtained high-resolution and high-precision inversion results, which have good application prospects.
Analysis of mechanical properties of single crystal copper under low-temperature indentation test
Authors: Wang Yunyi , Guo Jinyan , Liu Sihan , Wang Chao
Published: November 2024

As a common superconducting material in the aerospace field, the mechanical properties of single-crystal copper at low temperatures have attracted much attention. Combined with the current low-temperature nanoindentation test technology and the research status of micromechanical properties of crystal copper at home and abroad, this paper puts forward the low-temperature nanoindentation test on single-crystal copper. It analyzes the changes in mechanical properties of the low-temperature environment by indentation curve. Before the formal test, we first analyzed the Oliver-Pharr micro and nanoindentation test theory and described briefly the advantages of using nanoindentation to test the mechanical properties. The final test results show that in the temperature range of 300K~150K, the hardness and elastic modulus of the single-crystal copper increase with the decrease in temperature. The lower the temperature is, the faster the increase of hardness and elastic modulus is. At the same temperature, the hardness and elastic modulus of single-crystal copper with three crystal faces are (111) > (110) > (100). The mechanical properties at low temperatures are effectively reflected by means of low-temperature nanoindentation, which can be used to guide the production of materials in real life.
Calibration and characterization of the RED-100 detector at the Kalinin Nuclear Power Plant
Authors: Akimov D.Yu. , Aleksandrov I.S. , Ata-Kurbonova F.B. , Belov V.A. , Bolozdynya A.I. , Etenko A.V. , Galavanov A.V. , Gusakov Yu.V. , Khromov A.V. , Konovalov A.M. , Kornoukhov V.N. , Kovalenko A.G. , Kozlova E.S. , Koskin Yu.I. , Kumpan A.V. , Lukyashin A.V. , Pinchuk A.V. , Razuvaeva O.E. , Rudik D.G. , Shakirov A.V. , Simakov G.E. , Sosnovtsev V.V. , Vasin A.A.
Published: November 2024

RED-100 is a two-phase Xe detector designed and built for
the study of coherent elastic neutrino-nucleus scattering
(CEνNS) of reactor antineutrinos. A comprehensive calibration
was performed in order to obtain important parameters of the
detector during its operation at the Kalinin Nuclear Power Plant
(Tver region, Russia). This paper outlines the analysis of
calibration data, position and energy reconstruction procedures, and
calculation of the efficiency of electron extraction from the liquid
xenon to the gas phase.
Reflux extraction with saponification of crude wax from sugarcane filter cake for policosanol production
Authors: Hernandez JMS , Movillon JL , Capunitan JA , Arocena RE , Borines MG
Published: November 2024

Filter cake, a by-product in the sugar industry, has significant amount of wax containing policosanol which can be extracted using proper method and solvent. Policosanol is a mixture of high molecular weight aliphatic primary alcohols and was reported to reduce cardiovascular diseases. This study explored the use of hot ethanol reflux extraction to recover the crude wax from the filter cake followed by saponification for policosanol purification. Crude wax yield of 84.5 mg crude wax/g filter cake was obtained using reflux extraction at 60° C, 500 rpm and 12 mL absolute ethanol/g filter cake. The maximum crude wax yield obtained from Soxhlet extraction was 121.88 ± 0.46 mg crude wax/g dry filter cake, which corresponds to 69.33% recovery. Using a two-level factorial design, the effects of sodium hydroxide (NaOH) concentration (0.1 M and 1 M), reaction time (30 minutes and 60 minutes)and reaction temperature (30 °C and 60 °C) on the policosanol yield during saponification were determined. Results showed that NaOH concentration and temperature have significant effects on policosanol yield while reaction time alone is insignificant. Increasing both the reaction time and NaOH concentration can lead to an increase in policosanol yield. The highest yield of 1.234 ± 0.322 mg policosanol/g crude wax after saponification was obtained at 60 °C for 60 minutes with 1 M NaOH. This is twice the amount of policosanol recovered as compared to 0.583 ± 0.026 mg policosanol/g crude wax without saponification.
Greenhouse Gas Mitigation Potential of the Enhanced Rice Straw Biogas System in the Philippines
Authors: Gomez C C , Demafelis R B , Magadia B T , Matanguihan A E D , Estante E P V , Nuñez C J E , Sumague J V , Chong K , Roeder M , Jamieson C
Published: November 2024

Rice straw is an agricultural waste produced abundantly every rice cropping cycle. Its disposal or removal from the field is a problem to rice farmers every start of the next cropping cycle due to its labor-intensive collection from the field. One traditional practice is soil incorporation; however, rice straw does not degrade easily, and this management practice releases significant amount of greenhouse gas emissions to the environment. An attempt to solve this issue is to utilize rice straw with cattle manure as feedstock for biogas production and use the energy generated for rice post-harvest processing such as grain drying and milling. An Enhanced Rice Straw Biogas facility was constructed in Victoria, Laguna, Philippines and a trial lagoon run was conducted from June to October 2021. The data from the initial run was used as input to the modified Aston-developed Mass Energy Balance Model to determine the biogas production potential of rice straw and cattle manure as bioenergy feedstocks. The proposed system can produce 8,803,567.99 L (296.19 L/kg VS) of biogas which can be converted to 19,502.97 MW electricity and 84,512.86 MJ heat. From the energy generated per batch, 18,417.21 kg rice grain (dry season) or 15,752.79 kg rice grain (wet season) can be dried and milled, with an excess of equivalent kerosene (696.93 L for dry season or 248.46 L for wet season) and electricity (3,745.12 kWh for dry season or 6,182.23 kWh for wet season). Due to biogas utilization, an estimated 3,351 L of fossil-based kerosene and 12,185.91 kWh of electricity equivalent can be avoided. This low GHG emission rice production system (Aston Model) has a theoretical annual carbon footprint of 153,134 kg CO2e and a 28.21% reduction of greenhouse gas emissions compared to the conventional rice production system.
Effect of size and loading of waste single-used plastic (SUP) aggregates on a bio-based high density polyurethane composite
Authors: Tilendo A C , Uy K M M , Filipinas J Q , Marohomsalic K M A , Khalid J M , Sultan N N
Published: November 2024

The utilization of waste single-use plastic (SUP) as fillers by containment in a polyurethane matrix was investigated as an alternative solution to the detrimental disposal of these waste materials. High-density bio-based rigid polyurethane composites were prepared by adding polyol, isocyanate, and additives, along with densified SUP, which served as aggregate fillers to enhance the bulk density and flexural strength of rigid polyurethane while increasing the thermal conductivity. The aggregated SUPs were prepared using agglomeration-densification machine and exhibited size variations of 12.44 mm (A), 14.12 mm (B), and 15.56 mm (C). The resulting aggregates were added to the rigid polyurethane matrix at varied loadings of 40%, 50%, and 60% v/v. The green composites were cured in heated hydraulic press at constant temperature and pressure. Based on the obtained results, it was found that the formulation with a SUP size of C and a loading of 60% produced the composite of highest bulk density due to relatively high density of agglomerated SUP as the size enlarges. Additionally, the SUP size of A and a loading of 50% (50A) exhibited the highest flexural strength value. This behaviour was attributed to the increased filler-matrix interfacial area achieved with the smallest size aggregates. However, a further increase in aggregate loading resulted in a decrease in this property as common attribute for composite materials. On the other hand, it was revealed that increasing the loading of SUP aggregates provided a lesser insulating effect due to the increase in thermal conductivity resulting from the presence of filled pores within the polyurethane foam. The findings of this study contributed to understanding the effects of aggregate size and loading on the mechanical and thermal properties of the composite material, providing valuable insights for the development of energy-efficient and environmentally-friendly polyurethane structures.
Effect of Fatty Acid on Melting and Solidification of Erythritol
Authors: Wada Daiju , Tang Xudong , Tokushige Manabu , Ryu Junichi
Published: November 2024

One of the solutions to energy problems is the reuse of waste heat. One way to reuse waste heat is to use latent heat storage materials. Erythritol, of which melting point is the temperature range between 100 and 200°C, has attracted much attention as latent heat storage materials. However, as usual erythritol shows the large supercooling, its supercooling degree must be decreased to use for latent heat storage material. To achieve this, we have investigated the mixed erythritol with fatty acids as addition agents. Samples were prepared by physically mixing of erythritol and fatty acids such as (lauric acid, myristic acid, palmitic acid, and stearic acid). In this study, differential scanning calorimeter (DSC) was used (to evaluate the sample temperature program: 30→140→0→30°C, heating rate: 5°C/min, atmosphere: N2 gas). The degree of supercooling was calculated from the DSC curve. And also, a camera was used to capture and discuss the freezing process. The erythritol physically mixed with fatty acids showed a higher freezing point and lower degree of supercooling than pure erythritol. The mixing myristic acid with erythritol significantly lowers the supercooling degree. The erythritol sample with palmitic acid or stearic acid did not show as low supercooling degree as that with myristic acid. Additionally, with lauric acid or myristic acid, the erythritol sample solidified simultaneously, while sample solidified separately with palmitic acid or stearic acid added. In summary, it was found that physical mixing of fatty acids and erythritol decreased in the supercooling degree. Furthermore, the crystallization temperatures of the sample with lauric acid or myristic acid were altered by changing the fatty acids.
Exfoliation of Ti3 C2 MXene using (NH4 )2TiF6 Etchant and Simultaneous Synthesis of Ti3 C2 MXene/NH4 TiOF3 Mesocrystals Hybrids
Authors: Wang T , Zhu L , Zhu W Y , Kanda H
Published: November 2024

A new single-step method is suggested to fabricate block structures consisting of NH4TiOF3 wrapped around Ti3C2 MXene (Ti3C2) by etching Ti3AlC2 MAX phase with (NH4)2TiF6. The optimal reaction conditions for Ti3AlC2 MAX phase and (NH4)2TiF6 are systematically investigated. (NH4)2TiF6 selectively etches the Al in the Ti3AlC2 MAX phase and promotes promoting the mild hydrolysis reaction of (NH4)2TiF6 to form NH4TiOF3 crystals. The exterior shapes of Ti3C2/NH4TiOF3 hybrids can be tuned by adjusting the reagent concentration, reaction temperature. The phase composition, morphology and photophysical properties of the Ti3C2/NH4TiOF3 hybrids are investigated using various characterization techniques. Ti3AlC2 MAX phase reacts with (NH4)2TiF6 at 60 °C for 24 h to form hybrids which are surrounded by NH4TiOF3 crystals simultaneously with the formation of Ti3C2 nanosheet. The resulting Ti3C2/NH4TiOF3 are porous and finely structured, showing potential for various applications in biotechnology, sensing, and environmental fields. This method provides important insights into future applications of Ti3C2/NH4TiOF3 hybrids.
Preparation and Characterization of Water Hyacinth-Derived Cellulose Nanofibers for Fuel Cell Membrane application
Authors: Sansolis Alyssa Marie U. , Parreño Jr Ronaldo P. , Beltran Arnel B.
Published: November 2024

Cellulose nanofibers (CNF) derived from biomass materials were used for various applications such as medicine, packaging, wastewater treatment, and fuel cells. In this study, CNF was synthesized from water hyacinth plants obtained from Laguna de Bay. Collected water hyacinth stems were cleaned, washed, air-dried, and oven-dried for fiber extraction. Chemical and mechanical treatments were used to extract the CNF from the water hyacinth. The fibers were treated with 4 % potassium hydroxide solution and homogenized at 25,000 rpm for 3 mins. The resulting CNF was characterized using Scanning Electron Microscopy (SEM) to investigate the microstructures and morphology. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (AR-FTIR) was used to determine the chemical composition of the CNF. Lastly, crystallinity was examined by using an X-Ray Diffraction (XRD) to ensure that the extraction of CNF was successful. The resulting properties of CNF ensure its potential when used as a pure material or added as a composite for the membrane of fuel cells.
Synthesis of iron-loaded MFI-type (Fe/ZSM-5) zeolite using Philippine natural zeolites (PNZ) for potential adsorption and catalytic applications
Authors: Dumrigue Apraile Hope P. , Cosiñero Hannah Shamina O. , Potato Don Nelson C. , Tamargo Ramuel John I.
Published: November 2024

Philippine natural zeolites (PNZ) are locally abundant aluminosilicates used in different applications such as filtration and purification. However, the presence of impurities limits their usability. Structure modification of PNZ into a new framework was conducted in the study to address this issue. This study used PNZ as a precursor in the sustainable synthesis of iron-loaded MFI-type (Fe/ZSM-5) zeolite, a synthetic zeolite extensively studied for its excellent catalytic activity and high adsorption capacity. PNZ was depolymerized into active silica and alumina, then recrystallized via hydrothermal synthesis. Ammonium iron citrate (AIC) and TPAOH were used as the iron source and structure-directing agent, respectively. The disappearance and appearance of FTIR peaks in the depolymerized PNZ spectra deduced the successful destruction of the initial zeolite framework of the PNZ. The synthesized material was characterized using FTIR, XRD, SEM-EDS, TGA, and BET analyses. FTIR showed the crystallinity peak of MFI-type zeolite, while XRD confirmed its successful synthesis. SEM images show hierarchical aggregated particles suggesting the presence of intercrystalline and intracrystalline mesopores. The BET surface area of the synthesized zeolite increased by 168% compared to the raw PNZ, and TGA results show its high thermal stability. EDS analysis confirmed the presence of iron in the sample.
Liouville theorems for ancient solutions of subexponential growth to the heat equation on graphs
Authors: Hua Bobo , Yang Wenhao
Published: November 2024

Mosconi [Proc. Amer. Math. Soc. 149 (2021), pp. 897–906] proved Liouville theorems for ancient solutions of subexponential growth to the heat equation on a manifold with Ricci curvature bounded below. We extend these results to graphs with bounded geometry: for a graph with bounded geometry, any nonnegative ancient solution of subexponential growth in space and time to the heat equation is stationary, and thus is a harmonic solution.
Identifying critical periods of susceptibility for maternal exposure to biothermal stress and the risks of stillbirth and spontaneous preterm birth in Western Australia
Authors: Nyadanu Sylvester Dodzi , Tessema Gizachew A , Mullins Ben , Gasparrini Antonio , Pereira Gavin
Published: November 2024

A few studies investigated critical periods of temperature and the risks of stillbirth and preterm birth. This study aimed to identify critical periods of composite biothermal stress (Universal Thermal Climate Index, UTCI) for stillbirth and spontaneous preterm birth (sPTB). From the Midwives Notification System, 415,271 singleton births between 1st January 2000 and 31st December 2015 were linked to spatiotemporal UTCI in Western Australia. Covariate-adjusted weekly and monthly distributed lag non-linear Cox regression from twelve weeks before conception to birth were performed. Relative to median exposure (14.2 °C), extreme UTCI levels (1st–10th and 90th–99th centiles) were associated with higher hazards of stillbirth and sPTB, especially stronger at lower than higher exposures. Critical susceptible periods at 1st centile (10.2°C) exposure were found during gestational weeks 21–42 with the strongest hazard of 1.14 (95% CI 1.03, 1.27) in the 42nd week for stillbirth and during gestational weeks 26–36 with the strongest hazard of 1.09 (95% CI 1.06, 1.12) in the 36th week for sPTB. Monthly exposure showed a similar pattern but with greater magnitude. Mid to late gestation showed critical susceptible periods of biothermal stress on the birth outcomes, suggesting further studies and timely climate-related healthcare interventions.
Associations between community social capital and posttraumatic growth among older survivors 11 years after a natural disaster
Authors: Hikichi Hiroyuki , Kondo Katsunari , Kawachi Ichiro
Published: November 2024

We prospectively examined whether community-level social capital plays a significant role in developing Posttraumatic Growth (PTG) among older survivors of the 2011 Japan Earthquake and Tsunami. The baseline survey was conducted 7 months before the disaster among residents of a city located 80km west of the earthquake epicenter. The survey inquired about participants’ health status and social capital (informal socializing and social participation, and social cohesion). Approximately 2.5 years after the disaster, we surveyed older survivors to assess their disaster experiences. A follow-up survey in 2022 inquired about PTG in the 11 years following experiences of the disaster (n = 1,819). Multilevel linear regression analysis showed that pre-disaster community-level informal socializing and social participation was associated with higher PTG scores (coefficient = 0.25, 95% CI: 0.02, 0.47). In cross-classified multilevel regression, maintenance of higher community-level informal socializing and social participation during the post-disaster period was associated with higher scores of PTG (coefficient = 0.22, 95% CI: 0.07, 0.37). Pre-disaster community-level informal socializing and social participation was associated with higher PTG scores among older survivors. Interventions encouraging social interactions among neighbors may be effective in promoting PTG of survivors after natural disasters.
Investigating the service utilization and pathways of patients with alcohol use disorders
Authors: Zhang Jingxiang , Qian Siyu , Su Guoxin , Deng Chao , Reid David , Sinclair Barbara , Yu Ping
Published: November 2024

Background

Process mining was widely used in healthcare settings to analyse patient pathways, providing insights about patient care and resource allocation. This study aimed to apply process mining to explore service utilization and pathways of patients with alcohol use disorders in receiving the community-based Drug and Alcohol Service to establish a baseline for evaluating improvement initiatives.

Methods

Patients’ encounters with the Drug and Alcohol Service and their direct care activities (i.e. Intake, Assessment, and treatment service activities) that occurred in these encounters were analysed to depict the actual pathways. Patterns were uncovered from these actual pathways using a process mining tool Disco. Patients with alcohol use disorders were divided into two groups—patients who use polysubstance and those who do not—to compare their service utilization and pathway patterns.

Results

Five hundred seventy-one patients with alcohol use disorders incurred 1447 encounters, comprising 13,974 activities. The top three actual pathways with at least three activities were: (i) pathway ‘Intake-> Withdrawal Management-> Withdrawal Management’ (170 (11.7%) encounters and 130 (22.8%) patients); (ii) pathway ‘Intake-> Adult Counselling-> Adult Counselling’ (161 (11.1%) encounters and 126 (22.1%) patients); and (iii) pathway ‘Intake-> Assessment-> Withdrawal Management’ (155 (10.7%) encounters and 129 (22.6%) patients). However, 313 (21.6%) encounters did not proceed beyond the Intake stage. When the patients started their pathways from Intake, their immediate next activities were frequently Withdrawal Management, Assessment or Adult Counselling. Compared to those who do not use polysubstance, patients who use polysubstance had a higher proportion of Intake (19.3% vs 11.8%, P < .001), Involuntary Treatment (4.0% vs 1.0%, P < .001) and Magistrate Early Referral into Treatment (6.4% vs .3%, P < .001), but a lower proportion of Withdrawal Management (31.2% vs 39.0%, P < .001) and Adult Counselling (27.8% vs 37.6%, P < .001).

Conclusion

This study contributes to an in-depth understanding of service utilization and pathways of patients with alcohol use disorders within the community-based Drug and Alcohol Service. Future studies should investigate their reasons for dropping out after Intake.
Structural insights into the inhibition mechanism of glucosidase inhibitors toward kojibiose hydrolase belonging to glycoside hydrolase family 65
Authors: Nakamura Shuntaro , Miyazaki Takatsugu
Published: November 2024

Glycoside hydrolase family 65 (GH65) includes glycoside hydrolases active on various α-glucosides. We previously demonstrated that the GH65 enzyme from Flavobacterium johnsoniae (FjGH65A) is a kojibiose hydrolase and determined its 3-dimensional structure. In this study, the effects of glucosidase inhibitors on FjGH65A and their complex structures were analyzed to elucidate their inhibition mechanism. FjGH65A was competitively inhibited by 1-deoxynojirimycin (DNJ) and noncompetitively inhibited by castanospermine (CSP) with Ki values of 2.95 and 3.69 µm, respectively. The crystal structures of FjGH65A complexed with the inhibitors indicated that DNJ was bound to subsite −1 of FjGH65A, while CSP was bound to subsites −1 and +1 of FjGH65A. Compared with the glucose complex structure, the conformation of Tyr337 was changed in the CSP complex structure. These results provide new structural insights into the mechanism of inhibition against GH65 α-glucoside hydrolases.
Development of a protein production system using Ogataea minuta alcohol oxidase-deficient strain under reduced-methanol-consumption conditions
Authors: Tsuda Masashi , Nakatani Yuki , Satoshi Baba , Nonaka Koichi
Published: November 2024

Methylotrophic yeast is a useful host for producing heterologous proteins using the unique and strong alcohol oxidase 1 (AOX1) promoter, which is induced by methanol and repressed by various carbon sources. However, methanol is preferably avoided in industrial-scale fermentation given its toxicity, flammability, and explosiveness. To develop a protein production system under reduced methanol supply conditions, we attempted to characterize the AOX1 promoter induction activity by comparing derepression conditions with methanol induction conditions. This comparison is important because decreasing methanol consumption would enhance the industrial value of Ogataea minuta for heterologous protein production. For such a comparison, an alcohol oxidase-deficient (Δaox) strain was generated, with methanol only being used for AOX1 promoter induction. We also developed a culture process in a jar fermentor using the O. minuta Δaox strain under mixed feed conditions to achieve heterologous protein production comparable to that of the wild-type strain under low-methanol conditions.
d-limonene suppresses RANKL-induced osteoclast differentiation and promotes osteoblast activity in vitro
Authors: McCallum Lynn , Fox Simon W
Published: November 2024

Treatments for osteoporosis are typically given postfracture. Therefore, identifying safe prophylactic interventions to reduce fracture risk would be beneficial. One approach is to utilize the bioactive properties of natural compounds to modify osteoclast and osteoblast activity. d-limonene a well-tolerated, anti-inflammatory monoterpene found in citrus fruits holds promise due to its suppressive effect on NFκB, a key regulator of bone cell activity. We found that limonene promoted osteoblast differentiation and bone nodule formation and inhibited RANKL-induced osteoclast formation and bone resorption in vitro. Limonene also reduced the proresorptive signal provided by osteoblast, augmenting markers of osteoblast differentiation (alkaline phosphatase, osterix, and osteocalcin) and significantly decreasing osteoclastogenic cytokine production (PTHrP, IL-1β, and TNF-α). Therefore, limonene supplementation represents a potential route in combination with current interventions to optimize bone cell activity to maintain or enhance bone mass.
BS O06 - Management of Leaks post Bariatric Surgery: Recent Experience from a Tertiary Bariatric Surgery Referral Unit
Authors: Intrator Christina , Al Aaraj Mahmoud , Alkhaffaf Bilal , Techache Roukia , Alwani Omneya , Nimeh Bara Abu , Alabdellat Osama
Published: November 2024

Background

Bariatric surgery has been consistently demonstrated to provide effective long-term sustained weight loss and remission of several life-threatening conditions. The most common bariatric procedures undertaken globally include laparoscopic sleeve gastrectomy (SG) and gastric bypass2. These procedures are safe and have low associated mortality rates [0.05% SG, 0.09% single anastomosis gastric bypass (SAGB) and Roux-en-Y (RNYGB)]3. However, complications including staple line and anastomotic leaks can occur in up to 3% of patients and are associated with significant morbidity, thus requiring prompt identification and treatment4. Our study aims to analyse management of these leaks and establish an algorithm for our centre.

Method

This was a retrospective study of consecutive patients who experienced post-bariatric surgery leak between 2018 to 2024, in a regional tertiary bariatric surgery referral unit in the UK, serving a population of 5 million. The study included patients who underwent bariatric surgery in the UK or abroad (SG, RNYGB and SAGB), both primary and revision cases, and were subsequently diagnosed with post-operative leak. Patients were initially managed in our facility or referred to our centre for ongoing management of leak from other centres. Demographics, time to presentation, hospital length of stay (LOS), diagnostic investigations performed, and management approaches were analysed.

Results

22 patients (8 bypasses, 14 sleeves) were included. Mean time to presentation from index surgery was 19.6 days and mean LOS was 43.6 days. Initial management included conservative (3), endo-vacuum therapy (EVT) (4), stent (1), surgical (14) [9 laparoscopy and 5 laparotomy]. Surgical management comprised 7 T-tube insertions, 1 Foley catheter, 2 primary repairs, 2 EVTs, 1 washout and drain, and 1 stoma formation. Three patients required no further intervention, six needed different management approaches and three required re-operations. 7 patients were readmitted following discharge. Resolution of leak was achieved in all cases. There was no 90-day mortality.

Conclusion

Management of postoperative leak following bariatric surgery is a complex issue, requiring early identification, adequate drainage and control of sepsis, and maintenance of nutrition. Successful management requires a proactive and aggressive approach, including early clinical suspicion. Access to a range of interventions to support a dynamic approach to management is critical. The sequence and choice of management of leaks should be individualised according to each patient’s clinical presentation and investigation findings. A combination of different management approaches is often required for successful treatment of leak. Multicentre studies are needed to move closer to a consensus on managing bariatric leaks.
OGC O03 - Clinical Outcomes of Routine Jejunostomy Feeding Following Oesophagectomy
Authors: Ng Jessica Yan-Seen , Yi Cheang Catherine Jenn , Phillips Alexander
Published: November 2024

Background

Malnutrition negatively affects treatment outcomes of patients with oesophageal cancer post-oesophagectomy. Chemo(radio)therapy exacerbates nutritional deficits, and thus strategies to ensure adequate nutritional intake are necessary. Feeding jejunostomies are commonly used for nutritional support to maintain nutrition and reduce the effect of complications but may be associated with increased morbidity.

This study examines the impact of routine post-operative jejunostomy feeding on postoperative weight loss in patients who have undergone oesophagectomy.

Method

A retrospective review of patients undergoing oesophagectomy between January 2012-December 2014 and January 2016-December 2019 at a single oesophagogastric unit was performed. Routine post operative feeding with overnight feeding on discharge was introduced in 2015. 507 patients were identified and separated into two groups (245 without routine post operative jejunostomy feeding, 262 with routine feeding). Primary outcomes measured included post operative weight loss (2 weeks, 6 weeks, 3 months and 6 months). Secondary outcomes investigated included length of hospital stay, complications and long-term survival. Subgroup analyses were performed on patients who have experienced complications and those receiving different treatments.

Results

Weight loss was less in patients discharged with jejunostomy feeding at 2 weeks, 6 weeks, 3 months, 6 months (2.92kg vs 5.49kg, 3.39kg vs 6.37kg, 4.81kg vs 7.96kg, 7.25kg vs 9.285kg, p<0.05). In those with complications, routine feeding resulted in less weight loss up to 3 months (p<0.05). Jejunostomy feeding experienced less weight loss in subgroups surgery alone (7.99kg vs 8.72kg, p<0.001), neoadjuvant therapy with surgery (8.02kg vs 9.90kg, p<0.05), and neoadjuvant therapy, surgery with adjuvant therapy (6.29kg vs 9.14kg, p<0.05). Average hospital stay was 16 days with feeding, 19 days without. Long-term survival was greater with jejunostomy feeding (P=0.04).

Conclusion

Post-operative jejunal feeding is associated with significantly reduced post operative weight loss. This is reflected in patients who received surgery alone, neoadjuvant therapy with surgery and neoadjuvant therapy with surgery and adjuvant therapy. Patients with complications who had routine jejunostomy feeding also experienced significantly less weight loss than those without routine jejunostomy feeding. Routine jejunostomy feeding is associated with a shorter length of hospital stay and is associated with a greater long-term survival.
BN O05 - Physiological Transit Assessment of the Oesophagus In Patients With Anti-Reflux Surgery
Authors: Miah Ismail , Wong Terry , Gossage James , Zeki Sebastian , Jafari Jafar
Published: November 2024

Background

High-resolution manometry (HRM) is the gold-standard investigation for oesophageal motility in patients with dysphagia. The HRM findings may influence surgical decision for myotomy or anti-reflux surgery (ARS). However, HRM pitfall is the inability to measure oesophageal transit in parallel to the motility during physiology testing. Both transit and motility are complementary that offer insights in the pathophysiology and aetiology of the dysphagia symptoms.

This research evaluates the multichannel intraoesophageal impedance transit (MIIT) concept [1] to assess the oesophageal transit in symptomatic patients who undertook the postoperative oesophageal physiology testing between January 2020 and June 2024.

Method

This cross-sectional retrospective study selected patients with intact Nissen fundoplication (NF) wrap on gastroscopy or with known LINX implant in-situ. HRM with Chicago Classification (version 4.0)[2] compared the ARS cases with augmented antireflux barrier [AARB] from the surgery to healthy treatment naïve controls. The multichannel impedance-pH studies assessed both reflux and the MIIT [1]. MIIT >0.76 minutes were considered positive and comparable to GOJ outflow obstruction [1].

This project was approved by the NHS institution and the local research ethics committee (REC 18/NW/0120)(IRAS 333800).

Results

60 patients were found (NF 54, LINX implant 6)(females 30, mean age 51.3 years). 11 patients(18.3%) had pathological reflux despite ARS(DeMeester scores >14.72); 2 patients (18.2%) demonstrated hypotensive AARB. Conversely, 6 patients(10%) showed poor relaxation from the AARB and were compatible to outflow obstruction (5 patients [83.3%] showed conformation with MIIT >0.76 minutes). Patients with ineffective oesophagus (20%) and absent contractility(11.7%) showed MIIT >0.76 minutes in respectively two-thirds with ineffective oesophagus and in all patients with absent contractility. Normal HRM study was observed in 35 patients (58.3%) with 27 patients (77.1%) demonstrating MIIT >0.76 minutes.

Conclusion

MIIT was able to explain the post-surgical dysphagia in majority of patients from the equivalent transit to outflow obstruction (n=52 patients, 86.7%). Half of these cases had a normal HRM study and would have been perceived as having functional dysphagia. We would recommend performing MIIT adjunctive testing as part of postoperative oesophageal physiology assessment in symptomatic patients.

Incidentally, we observed 16 patients (26.7%) having hypotensive AARB post ARS comparing to healthy treatment naïve controls with 2 patients (12.5%) having persistent pathological reflux who may still benefit from surgical revision.

References

[1] https://doi.org/10.1136/gutjnl-2020-bsgcampus.41

[2] https://onlinelibrary.wiley.com/doi/10.1111/nmo.14058
MS O02 - OGC An audit of waiting times of the oesophagogastric cancer diagnostic pathway at a high-volume, tertiary centre
Authors: Velayudham Ganesh , Fox Sebastian , Griffiths Ewen
Published: November 2024

Background

The oesophagogastric cancer (OGC) staging pathway is extensive, contributing to prolonged waiting times from referral to treatment. NHS England guidance details the ideal timeframe from referral to finalisation of the patient’s treatment plan and stipulates a time of 21 days from OGD to communication of the treatment plan to the patient. This audit aims to compare pathway times at a tertiary cancer centre, which accepts referrals from seven different hospitals, to the current NHS target and further stratify pathway times according to patient characteristics and referring hospitals.

Method

Data was collected using a prospectively collected database of OGC patients who underwent staging investigations at the tertiary centre between October 2022 and October 2023. The primary outcome was OGD to communication of the treatment plan. Secondary outcomes included time from OGD to first staging investigation and the proportion of patients that had a next-day computed tomography (CT) scan. Outcomes were stratified to investigate inter-hospital variation and the effect of curative status and tumour location. Data was expressed as median and interquartile range (IQR) for continuous data or n (%) if categorical.

Results

263 patients were included in this audit with a median age of 69.0 (IQR 61.5-77.0). 13.8% of patients satisfied the target time of 21 days from OGD to communication of treatment plan. Curative patients had a longer median pathway time than palliative patients (49.0 vs 35.0 days), whereas oesophageal and gastric cancer patients had similar pathway times (44.0 vs 44.5 days). Patients diagnosed at the tertiary centre had a faster time from OGD to first staging investigation than patients diagnosed at non-specialist centres. Only 13.3% of patients had a next-day CT scan following their OGD (median time 5.0 days).

Conclusion

The OGC staging pathway is considerably slower than the target. Faster pathway times in palliative patients can be attributed to many of these patients not requiring further staging post-CT. Potentially, targets should be re-evaluated to distinguish between palliative and curative patients. The faster staging process at the central hospital may be explained by more regular clinics run by specialist clinicians and the prompt requesting of staging investigations without awaiting MDT discussions. Alongside increasing the proportion of next-day CT scans, these factors must be addressed to streamline the entire pathway.