bluuebunny/crossref_metadata_2025 huggingface dataset:
Low frequency electrostatic mode generated by electromagnetic waves in the Earth’s inner magnetosphere with two distinct electrons
Authors: Liu Yong , Qian Yousheng
Published: November 2022

The generation of low frequency electrostatic mode by parametric decay of electromagnetic waves (EMWs) in the Earth’s inner magnetosphere with exponentially truncated kappa distributed hot electrons and cold electrons is studied. Nonlinear dispersion equation for the parametric process is derived from kinetic theory. The parametric instability of EMWs decay into low frequency electrostatic normal mode (ion acoustic like wave modes and electron acoustic wave modes) and electrostatic quasi–mode in the Earth’s inner magnetosphere are numerically analyzed. It is shown that parametric instability occurs only when the EMW is sufficiently strong if the collisions between ions and electrons are taken into account. The growth rate and the threshold conditions of the decay instability depend on the concentration and distribution of hot electrons. Because they change the dispersion and the damping rate of normal mode, the collisional damping of sideband EMW. In addition, the excitation of electrostatic normal mode by parametric decay of EMWs is more difficult than the excitation of electrostatic quasi–mode. The growth rate of EMWs decaying into electrostatic quasi–mode is much larger than the ones of decaying into electrostatic normal mode. But the frequency of electrostatic quasi–mode corresponding to the maximum growth rate can be as low as a few tens Hz. The mechanism may excite the electrostatic mode with frequency comparable to those of the ultra–low frequency electric fields observed in the Earth’s inner magnetosphere.
Natural climate solutions in Indonesia: wetlands are the key to achieve Indonesia’s national climate commitment
Authors: Novita Nisa , Subarno  , Lestari Nurul Silva , Anshari Gusti Zakaria , Lugina Mega , Yeo Samantha , Malik Anjelita , Asyhari Adibtya , Putra Chandra Agung Septiadi , Gangga Adi , Ritonga Rasis Putra , Albar Israr , Djaenudin Deden , Arifanti Virni Budi , Poor Erin , Jupesta Joni , Tryanto Dede Hendry , Basuki Imam , Ellis Peter
Published: November 2022

Indonesia offers a dramatic opportunity to contribute to tackling climate change by deploying natural climate solutions (NCS), increasing carbon sequestration and storage through the protection, improved management, and restoration of drylands, peatlands, and mangrove ecosystems. Here, we estimate Indonesia’s NCS mitigation opportunity for the first time using national datasets. We calculated the maximum NCS mitigation potential extent using datasets of annual national land cover, peat soil, and critical lands. We collated a national emissions factor database for each pathway, calculated from a meta-analysis, recent publications from our team, and available literature. The maximum NCS mitigation potential in 2030 is 1.3 ± 0.04 GtCO2e yr−1, based on the historical baseline period from 2009–2019. This maximum NCS potential is double Indonesia’s nationally determined contribution (NDC) target from the forestry and other land use sector. Of this potential opportunity, 77% comes from wetland ecosystems. Peatlands have the largest NCS mitigation potential (960 ± 15.4 MtCO2e yr−1 or 71.5 MgCO2e ha−1 yr−1) among all other ecosystems. Mangroves provide a smaller total potential (41.1 ± 1.4 MtCO2e yr−1) but have a much higher mitigation density (12.2 MgCO2e ha−1 yr−1) compared to dryland ecosystems (2.9 MgCO2e ha−1 yr−1). Therefore, protecting, managing, and restoring Indonesia’s wetlands is key to achieving the country’s emissions reduction target by 2030. The results of this study can be used to inform conservation programs and national climate policy to prioritize wetlands and other land sector initiatives to fulfill Indonesia’s NDC by 2030, while simultaneously providing additional co-benefits and contributing to COVID-19 recovery and economic sustainability.
Agricultural bio-waste of corn silk-derived porous carbon for high-performance supercapacitors
Authors: Taslim Rika , Halbi Suryandri , Apriwandi Apriwandi , Taer Erman
Published: November 2022

This study aims to develop a novel, simple, efficient, and low-cost method to prepare hierarchical porous carbon nanofiber derived from corn silks (CSAC) through a one-step carbonisation-physical activation process. The carbon precursors were activated by KOH solution at a high pyrolysis temperature to prepare activated porous carbon as an electrode material for supercapacitors without using binders. This study focused on the effect of different activation temperatures of 600, 700, 800, and 900 °C on the production of highly porous carbon nanofiber. An enhancement mechanism is proposed, which not only performed high nanofiber structures to possess the large specific active surface area to enhance energy density but also achieved micro-mesopore combination to realise fast ion-transport channels for boosting high power density. A maximum specific surface area of approximately 1096.95 m2 g−1 was achieved by CSAC7. Furthermore, the electrochemical performance was evaluated using 1 M H2SO4 solution as an electrolyte through a novel two-electrode binder-free system. The electrode materials produced a maximum specific capacitance of 237 F g−1 at a current density of 1 A g−1. These excellent characteristics show that the synthetic approach has a great potential for fabricating high-performance supercapacitors.
Tribology model to characterise shoe friction and wear behaviours and its application to evaluating traction properties
Authors: Kim In-Ju
Published: November 2022

Wear and tear growths of shoes are unavoidable, but this issue has hardly been investigated in the literature from the viewpoint of slip resistance to prevent pedestrian falls. This study suggests a shoe tribology model to explore friction and friction-induced wear developments of shoe heel/sole surfaces and identify their effects on traction controls. To verify the model, dynamic friction tests were performed between two popular shoe kinds: Polyurethane and Polyvinyl Chloride against a vinyl sheet under dry conditions. Their results were investigated quantitatively and qualitatively. Results clearly show that traction properties are not constant and primarily depend on material types. Findings from this study may enhance our understanding of shoe surface friction and wear behaviours and provide helpful information to develop better designs for heels/soles to prevent pedestrian fall incidents.
Surface morphology evolution of C-plane sapphire during multi-step thermal annealing
Authors: Yadav Mahesh J , Aravindan S , Rao P V , Maithani Yogita , Singh J P
Published: November 2022

The surface morphology evolution of the C-plane (0001) sapphire surface with the 4° miscut angle towards A-plane is thermally annealed at temperatures of 1100 °C and 1200 °C for different dwell times varying between 3-12 hours in multiple steps, resulting in a total of 30 hours. Atomic Force Microscopy (AFM) observations are used to systematically study the effects of the thermal annealing process, temperature, and time on the evolution of the periodicity and step height of structures. The step-terrace structures with straight step-edges along the

[
1

1

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00
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direction were observed over the entire surface after 3 hours of annealing at 1100 °C. The step-terrace structure morphology evolves through the step-bunching and facet coarsening mechanisms during the multi-step thermal annealing process. Step-bunching begins with the formation of contact points between the adjacent steps by diffusion of atoms. Its onset is associated with a threshold value of the periodicity of step-terrace structures. By varying the annealing temperature during the multi-step thermal annealing process, the evolution of step-terrace structures can be manipulated by delaying the process of step-bunching.
Untargeted metabolomics to analyze alterations in two-dimensional graphdiyne–copper nanocomposite on the metabolic reprogramming of prostate cancer
Authors: Zhang Yixun , Xie Wenjie , Lin Jundong , Zhuo Yangjia , Zou Zhihao , He Huichan , Xu Qianfeng , Tang Zhenfeng , Tan Huijing , Liu Ren , Deng Yulin , Cai Shanghua , Ye Jianheng , Wang Lude , Zou Fen , Zhong Weide
Published: November 2022

Prostate cancer (PCa) is a common type of cancer in men worldwide. Metabolic reprogramming is an important factor in its pathogenesis. Two-dimensional (2D) nanomaterials have tremendous potential for cancer treatment owing to their unique physicochemical properties. However, very few studies have focused on the metabolic reprogramming mechanisms of PCa using 2D nanomaterials. In this study, for the first time, 2D graphdiyne (GDY) was used as a template to immobilize copper (Cu) ions to form a novel nanocomposite (GDY–Cu). GDY provides a large π-conjugated architecture that spatiotemporally restricts Cu ions spatiotemporally to realize the functional moiety of Cu ions as tumor therapeutics. The GDY–Cu nanocomposite with a 2D morphological structure was characterized using a transmission electron microscopy (TEM) and atomic force microscopy. The distribution of Cu loaded on the GDY was confirmed by high-resolution TEM with energy-dispersive x-ray spectroscopy analysis. In vitro and in vivo, GDY–Cu exhibits a good antitumor effect and is associated with specific metabolic reprogramming characteristics of PCa. In this study, the effect of GDY–Cu on the metabolic reprogramming of PCa cells was analyzed using untargeted metabolomics. Differences in metabolites in DU145 cells treated with GDY–Cu were analyzed by clustering and target analysis using bioinformatics methods. GDY–Cu inhibited the growth of PCa cells by decreasing the expression levels of acetyl-CoA carboxylase and cytoplasmic acetyl-CoA synthase, which inhibits the synthesis of related fatty acids and lipid metabolism. These results indicated that GDY–Cu inhibits the growth of PCa cells mainly via lipid metabolic pathways. At present, combinatory therapeutic modalities based on GDY and Cu are in their infancy. Further exploration is required to promote the development of 2D nanocomposite combinatory therapeutic modalities based on metabolic reprogramming.
Mechanical behaviour of stir cast TiO2/Redmud/Al6061 metal matrix composites
Authors: Hugar Niranjan , Narayana B Venkata , Waddar Sunil
Published: November 2022

The present work deals with mechanical characterization of titanium oxide (TiO2)/Redmud/Aluminium alloy 6061 (Al6061) hybrid metal matrix composites (HMMC’s) processed using stir casting method. The weight fractions of TiO2 are varied (2%,4% and 6%) and amount of redmud is kept constant (2%) in Al6061. The optimised parameters for stir casting are employed for fabrication the samples of all the configurations and cut according to ASTM standards. The presence of the elements of the constituents is confirmed by XRD and EDS. Effect of TiO2 and redmud content on Tensile, Compression and Hardness are studied in detail. The results reveal that the tensile, compressive and hardness of the prepared composites enhance with TiO2 content. The yield and ultimate strength increase in the range of 29.77%–72.36% and 29.96%–63.90% respectively than the Al6061. The compressive strength enhanced in the range of 9.28%–33.20% than the Al6061. Enhancement of hardness in the range of 9.41%–41.17% is observed as compared to Al6061. The fractography studies confirm uniform mixing of the constituents and load transfer mechanism.
Using microfluidic technology to measure the terahertz absorption properties of phase-changing thermoregulated emulsions
Authors: Jin Jing-Yi-Ran , Peng Bo , Meng Qing-Hao , Qian Si-Yu , Su Bo , Cui Hai-Lin , Zhang Cun-Lin
Published: November 2022

Phase-changing materials (PCMs) are widely used thermal-energy-storage substances that utilize the absorption and emission of heat during the solid–liquid–solid phase change of a substance to store and release thermal energy, which is closely related to their structural properties. This paper combines THz technology with microfluidic technology to investigate the THz spectral properties of phase-changing thermoregulated emulsions and the results show that: with the increase of the applied magnetic field strength, more molecules are magnetized and arranged with orientation, and the transmission intensity of THz increases; with the increase of the applied electric field strength, the bond length of covalent bonds becomes larger, and the transmission intensity of THz increases; during the cooling process, the free energy of molecules decreases, and the transmission intensity of THz increases. The results provide technical and data support for the in-depth study of phase-changing thermoregulated emulsions, which is important for the fine study and improvement of properties in different environments in aerospace and coating fields.
Simultaneous effect of activated carbon and chlorophyll pigment from leaves of acacia nilotica on the enhancement of electron transfer in DSSC applications
Authors: Dhanasekaran P , Marimuthu R
Published: November 2022

A well-defined attempt has been made to confirm the impact of green dye with activated carbon on the performance of Dye-sensitized solar cell (DSSC) compared to the natural red dye as sensitizer. Green dye from the leaf of Acacia Nilotica combined with the activated carbon derived from coconut Shell and red dye from beet root with activated carbon extracted using ethanol have been used to fabricate dye-sensitized solar cells. The pH of the extracts confirms the acidic nature of the dyes. The chlorophyll pigments in the green dye and activated carbon particles have pronounced effect for the efficiency of the solar cell. It is found that the solar cell with green dye and activated carbon has given an efficiency of 0.69% with fill factor, open circuit voltage and short circuit current density of 0.5361, 0.65 V and 2.0 mA cm−2. The red dye with activated carbon as sensitizer has given the efficiency of 0.504%. Analysis of the green dye with activated carbon in DSSC has proven the enhanced electron injection with low charge transfer resistance of 58 Ω and higher rate of reduction of redox couple I−/I3
−.
Erosion behavior and mechanism of Cu-B4C composites under arc discharge in different atmospheres
Authors: Li Xinchao , Feng Yi , Wang Fei , Liu Zhuhan , Zhou Zijue , Yu Miao , Jiang Ningyuan
Published: November 2022

Ceramic particle-reinforced materials are an important part of high-performance contact materials because of the excellent performance in resistance to arc erosion. In particular, B4C is the ideal choice for the preparation of high-performance electrical contact materials because of its excellent physicochemical properties. In this paper, Cu-B4C composites were prepared by hot-press sintering technology to illustrate the arc erosion behavior of Cu-B4C composites in different atmospheres at high voltages. The erosion morphology and composition of Cu-B4C composites after erosion in air, carbon dioxide and sulfur hexafluoride atmosphere at 8kV were studied. The different erosion mechanisms of Cu-B4C composites in air, carbon dioxide and sulfur hexafluoride atmospheres were systematically discussed. The results showed that the Cu-B4C composites exhibited inhomogeneous erosion in all three atmospheres, and the erosion was mainly concentrated in the region around the B4C particles. In air, the Cu-B4C composites were most severely eroded, but showed better erosion resistance in carbon dioxide and sulfur hexafluoride. The experimental atmosphere decomposed and reacted with copper on the cathode surface at high temperatures, while B4C maintained a good structure after erosion.
Mechanical properties and impact energy release characteristics of Al0.5NbZrTi1.5Ta0.8Ce0.85 high-entropy alloy
Authors: Ma Yusong , He Jinyan , Zhou Liang , Zhang Kaichuang , Gai Xiqiang , Zhang Xinggao
Published: November 2022

To explore the potential of high-entropy alloys (HEAs) as energetic structural materials (ESMs), Al0.5NbZrTi1.5Ta0.8Ce0.85 high-entropy alloys were prepared by vacuum arc melting. XRD and TEM indicated the coexistence of BCC and FCC structures. SEM images illustrated element segregation in HEA. HEA exhibited excellent mechanical properties and impact energy release characteristics. When the strain rate increased from 10–3 s−1 to 4500 s−1, the yield strength increased by 56.2% from 909 MPa to 1420 MPa. Under impact, the threshold of strain rate of HEA was about 1200 s−1. Ballistic gun tests were performed to investigate the penetration behaviour and energy release characteristics. Al0.5NbZrTi1.5Ta0.8Ce0.85 could penetrate 6 mm A3 plate at the speed of 712 m s−1 and ignite the cotton behind the target, combining excellent mechanical properties and impact energy release characteristics.
Overview of machine learning applications in fusion plasma experiments on J-TEXT tokamak
Authors: ZHENG Wei , XUE Fengming , SHEN Chengshuo , ZHONG Yu , AI Xinkun , CHEN Zhongyong , DING Yonghua , ZHANG Ming , YANG Zhoujun , WANG Nengchao , ZHANG Zhichao , DONG Jiaolong , TANG Chouyao , PAN Yuan
Published: November 2022

Machine learning research and applications in fusion plasma experiments are one of the main subjects on J-TEXT. Since 2013, various kinds of traditional machine learning, as well as deep learning methods have been applied to fusion plasma experiments. Further applications in the real-time experimental environment have proved the feasibility and effectiveness of the methods. For disruption prediction, we started by predicting disruptions of limited classes with a short warning time that could not meet the requirements of the mitigation system. After years of study, nowadays disruption prediction methods on J-TEXT are able to predict all kinds of disruptions with a high success rate and long enough warning time. Furthermore, cross-device disruption prediction methods have obtained promising results. Interpretable analysis of the models are studied. For diagnostics data processing, efforts have been made to reduce manual work in processing and to increase the robustness of the diagnostic system. Models based on both traditional machine learning and deep learning have been applied to real-time experimental environments. The models have been cooperating with the plasma control system and other systems, to make joint decisions to further support the experiments.
A quantum science space station
Authors: Thompson Rob , Mahageg Makan , Kellogg Jim , Mosher Todd , Ramadorai Ray , Ruttley Tara , Wagner Erika , Woerner Lisa
Published: November 2022

In the coming years we expect to see a diverse array of quantum instruments being developed and flown in space, including quantum gas experiments, optical clocks, atom interferometry experiments, and quantum information/quantum optics experiments. The International Space Station has proven itself as an exceptional platform for such missions, providing long-term microgravity in a pressurized and temperature controlled environment, with ample power, thermal and data resources. However the station is currently planned to operate only through 2030, well before many proposed quantum sciences missions could be ready for launch, and we undertake here to explore what an ideal follow-on platform might look like. In particular, we believe that a much smaller and less expensive low Earth orbiting facility, optimized and dedicated to quantum science, could be an exceptionally powerful platform for exploring the quantum world and harnessing quantum technology. Such a platform would allow multiple quantum instruments to share resources and explore related phenomena in concert.
Land pollution research: progress, challenges, and prospects
Authors: Gao Ling , Hu Tianzhen , Li Li , Zhou Maoyuan , Zhu Baoqing
Published: November 2022

This paper comprehensively searched all the literature on the subject of ‘land pollution’ through the core collection of the Web of Science database, and systematically processed the research literature from 1944 to 2021 using CiteSpace software, and carried out bibliometric analysis and visual presentation, which uncovers the LP research dynamics in detail, and draw the following conclusions: First, through the indicator of betweenness centrality, the basic authors and journals of the subject are obtained; from the perspective of publishing institutions and affiliated countries, the United States is an important research center for LP. Second, keywords such as ‘land use’, ‘air pollution’, ‘impact’, ‘soil pollution’ and ‘management’ are all high-frequency words. The results of keyword clustering and co-citation information in the literature indicate the natural-social dimensions of LP research, such as the use and quality of air, land, and water, as well as urbanization and environmental policies. However, challenges remain and current LP studies are still characterized by a certain degree of fragmentation, which should be enriched by combining land use changes and should require combining experimental results with socioeconomic analysis to propose joint LP remediation approaches. Finally, local and regional forces may strongly influence the LP process, and the drivers of globalization should be emphasized.
Analytical subthreshold current model of the dual-material tri-gate (DMTG) MOSFET and its application for subthreshold logic gate
Authors: Liu Wentao , Chiang Te-Kuang , Yan Yan , Liou Juin J
Published: November 2022

Multi-gate MOSFETs are considered for realizing ultra-low-power circuits due to their superior channel control capability and short channel effect (SCE) resistance. To achieve this goal, it is necessary to establish a suitable compact device circuit model for them. However, current research focuses more on single-material multi-gate MOSFET, and there is no research report on dual-material logic gates. In this work, we develop a subthreshold current model for dual-material tri-gate (DMTG) MOSFET. It is found that the gate metal close to the source can affect the subthreshold characteristics of the transistor to a greater extent. Moreover, combined with the equivalent transistor model, the noise margin (NM) model of the subthreshold inverter composed of DMTG MOSFETs is developed. The nearly equal NM can be obtained by equal NM design (END). An appropriate work function can be selected through END to obtain the optimal NM when designing the inverter. The NM under different device geometric parameters is given, and the simulation result shows that the model accuracy reaches 98%. Finally, the effect of DMTG structure on the device drain induced barrier lowering (DIBL) is given, which effectively reduces DIBL by 42%. These models still remain high accuracy when the device channel length shrink down to 20 nm, which provide the possibility for DMTG MOSFET to be effectively applied to ultra-low-power circuits.
Neuromorphic model of hippocampus place cells using an oscillatory interference technique for hardware implementation
Authors: Zhaoqi Chen , Nasrallah Alia , Alemohammad Milad , Furuta Masanori , Etienne-Cummings Ralph
Published: November 2022

In this paper, we propose a simplified and robust model for place cell generation based on the oscillatory interference (OI) model concept. Aiming toward hardware implementation in bio-inspired simultaneous localization and mapping (SLAM) systems for mobile robotics, we base our model on logic operations that reduce its computational complexity. The model compensates for parameter variations in the behaviors of the population of constituent theta cells, and allows the theta cells to have square-wave oscillation profiles. The robustness of the model, with respect to mismatch in the theta cell’s base oscillation frequency and gain—as a function of modulatory inputs—is demonstrated. Place cell composed of 48 theta cells with base frequency variations with a 25% standard deviation from the mean and a gain error with 20% standard deviation from the mean only result in a 20% deformations within the place field and 0.24% outer side lobes, and an overall pattern with 0.0015 mean squared error on average. We also present how the model can be used to achieve the localization and path-tracking functionalities of SLAM. Hence, we propose a model for spatial cell formation using theta cells with behaviors that are biologically plausible and hardware implementable for real world application in neurally-inspired SLAM.
Developing a core outcome set for hospital deprescribing trials for older people under the care of a geriatrician
Authors: Martin-Kerry Jacqueline , Taylor Jo , Scott Sion , Patel Martyn , Wright David , Clark Allan , Turner David , Alldred David Phillip , Murphy Katherine , Keevil Victoria , Witham Miles D , Kellar Ian , Bhattacharya Debi
Published: November 2022

Background

Half of older people are prescribed unnecessary/inappropriate medications that are not routinely deprescribed in hospital hence there is a need for deprescribing trials. We aimed to develop a Core Outcome Set (COS) for deprescribing trials for older people under the care of a geriatrician during hospital admission.

Methods

We developed a list of potentially relevant outcomes from the literature. Using a two-round Delphi survey of stakeholder groups representing older people and carers, hospital clinicians, hospital managers, and ageing/deprescribing researchers, each outcome was scored according to Grading of Recommendations Assessment, Development and Evaluation, followed by two consensus workshops to finalise the COS.

Results

Two hundred people completed Round 1 and 114 completed Round 2. Representing all stakeholder groups, 10 people participated in workshop 1 and 10 in workshop 2. Six outcomes were identified as most important, feasible and acceptable to collect in a trial: number of prescribed medicines stopped; number of prescribed medicines with dosage reduced; quality of life; mortality; adverse drug events and number of hospital stays. Three other outcomes were identified as important, but currently too burdensome to collect: number of potentially inappropriate medicines prescribed; burden from medication routine; and medication-related admissions to hospital.

Conclusions

A COS represents the minimum outcomes that should be collected and reported. Whilst uncommon practice for COS development, the value of considering outcome collection feasibility is demonstrated by the removal of three potential outcomes that, if included, may have compromised COS uptake due to challenges with collecting the data.
Graded Depth of Response and Neoplastic Plasma Cell Index as Indicators of Survival Outcomes in Patients With Multiple Myeloma Following Autologous Stem Cell Transplant
Authors: Das Nupur , Dahiya Meetu , Gupta Ritu , Kumar Lalit , Rani Lata , Gupta Anubha , Farswan Akanksha , Sharma Atul , Sharma Om Dutt
Published: November 2022

Objectives

With a substantial number of patients with multiple myeloma (MM) experiencing disease relapse, the quest for more sensitive methods to assess deeper responses indicative of cure continues.

Methods

In this prospective analysis of 170 patients with MM at day 100 after autologous stem cell transplant, we evaluated the predictive value of conventional response, measurable residual disease (MRDTOTAL: the aberrant percentage of plasma cells [PC%] among total bone marrow cells), and neoplastic plasma cell index scores (NPCI: the aberrant PC% of total PCs).

Results

Significantly better progression-free survival (PFS) and overall survival (OS) were observed with deepening conventional response. Conventional response–based stratification within the MRD-positive and MRD-negative subgroups showed a significantly higher PFS (hazard ratio [HR], 3.11; P < .005) and OS (HR, 3.08; P = .01) in the conventional response-positive/MRD-positive group compared with the conventional response-negative/MRD-positive group. Using K-adaptive partitioning to find the optimum threshold for MRD, patients achieving less than 0.001% MRDTOTAL had superior PFS (MRDTOTAL 0.001% to <0.1%: HR, 6.66, P < .005; MRDTOTAL ≥0.1%: HR, 11.52, P < .005) and OS (MRDTOTAL 0.001% to <0.1%: HR, 5.3, P < .05; MRDTOTAL ≥0.1%: HR = 9.21, P < .005). The C index and Akaike information criterion metrics demonstrated the superior performance of the NPCI compared with MRDTOTAL in predicting treatment outcome.

Conclusions

Progressive deepening of response, conventional as well as MRD, correlates with superior survival outcomes. The NPCI proved to be a superior determinant of survival and can be explored as a better statistic than MRD.
Biogeographical events, not cospeciation, might be the main drivers in the historical association betweenNoctiliostreblaspecies (Streblidae) and their bulldog bat hosts
Authors: Alcantara Daniel Maximo Correa , Graciolli Gustavo , Antunes Junior Manuel , Toma Ronaldo , Nihei Silvio Shigueo
Published: November 2022

The genus Noctiliostrebla Wenzel (Diptera: Streblidae) stands out for its high degree of specificity exhibited in relation to bat species of the genus Noctilio Linnaeus and provides an exciting system for understanding the history behind host–parasite associations. Here, we present a phylogeny of Noctiliostrebla based on an analysis of DNA sequences and morphological characters, along with cophylogenetic and biogeographical analyses. Our results strongly support the monophyly of Noctiliostrebla, but with uncertainties within the genus. With a low frequency of cospeciation events explaining the associations between hosts and parasites, cophylogenetic analyses did not show an overall congruence between the host and parasite phylogenies. Indeed, two parallel histories were recovered in the host–parasite associations, which might indicate that niche segregation is determined evolutionarily, facilitating the coexistence of parasites and promoting diversification. Biogeographical analysis showed a strong spatial congruence between disjunct distributions of Noctiliostrebla and major river basins in South America and with areas of higher elevation, which might be associated with the glacial periods throughout the Pliocene and Pleistocene. Overall, our findings suggest an agreement with the expectations of the ‘Stockholm paradigm’ framework, in which biogeographical events and ecological factors act as important components to explain the associations, instead of cospeciation events.
P02 Utilising electronic PROMs to measure a change in health following elective laparoscopic cholecystectomy: a feasibility study
Authors: Daliya P , Carvell J , Lobo DN , Parsons SL
Published: November 2022

Introduction

The collection of Patient Reported Outcome Measures (PROMs) has many benefits for clinical practice. However, there are also many barriers that prevent them from becoming a part of routine clinical care. The aim of this feasibility study was to pilot the use of a digital platform to facilitate the routine collection of pre- and postoperative electronic PROMs (ePROMs) in patients undergoing elective laparoscopic cholecystectomy, and to validate the use of existing PROs for our population.

Methods

Patients listed for elective laparoscopic cholecystectomy were asked to complete digital versions of the Otago gallstones Condition-Specific Questionnaire (CSQ), and the RAND 36-item health survey (SF36). An assessment of methodological quality of ePROM questionnaires was also performed.

Results

Preoperative ePROMs were completed in 200 patients undergoing laparoscopic cholecystectomy. Despite participant drop out a significant improvement in quality of life was seen across all health domains postoperatively when compared with baseline preoperative values for both disease specific (emotional functioning; preoperative: 48.9, 30-days: 15.6, 3-months: 16.7, 6-months: 7.9, p < 0.05) and generic (emotional well-being; preoperative: 60.1, 30-days: 73.7, 3-months: 74.3, 6-months: 73.5, p < 0.05) PROMs. Methodological quality was assessed as good to excellent in both digital questionnaires used.

Conclusion

The collection of ePROMs is possible with current technological advances. Although it may be an acceptable and convenient process for patients, and a useful measure of quality-of-life trends for clinicians, further developmental work is necessary to improve accessibility for patients and to reduce reporting bias.

Take-home message

ePROMs are an acceptable and useful measure of quality-of-life trends for patients and clinicians, however further development is required to improve its usability in the clinical setting.
P16 Endoloop ligatures in the retrieval of urethral foreign bodies: a narrative review
Authors: Narroway H , Parkin C , Latif E
Published: November 2022

Introduction

Self-insertion of foreign bodies into the urethra has been described previously in patients presenting to hospital emergency services. Treatment typically involves procedural retrieval under local anaesthesia using basket or forceps, cystoscopy, or open surgery. An Endoloop is a device designed to snare colonic polyps during endoscopy with nylon loops. It is not traditionally used for retrieval of urethral foreign bodies. Our objective was to determine the incidence, safety and efficacy of this approach.

Methods

A narrative review was performed. Primary outcomes were technical success, defined as uncomplicated retrieval of foreign body, and adverse events related to pain, bleeding, infection, and damage to structures. Electronic searches were performed using PubMed, Embase and Google Scholar. Reference lists of selected studies were searched manually.

Results

2 case studies met inclusion criteria for analysis, both describing self-insertion of urethral foreign bodies for purposes of sexual arousal. These comprised a 30-year-old male (magnets) and a 29- year-old female (metal urethral sound). Both patients underwent successful retrieval of foreign body using an Endoloop ligature. There were no symptoms post-operatively and no procedural complications were reported.

Conclusion

An Endoloop ligature should be considered in conjunction with endoscopy when difficulties are experienced or anticipated with basket or forceps retrieval. Follow-up is mandatory to monitor for complications due to foreign body insertion such as urethritis, incontinence, fistula and diverticulum formation. Referral to psychological services is encouraged to reduce the risk of recurrence. Further studies are required to validate the efficacy and safety of this technique.

Take-home message

An Endoloop ligature should be considered in conjunction with endoscopy when difficulties are experienced or anticipated with basket or forceps retrieval of urethral foreign bodies.
P18 Assessment of da Vinci robotic system for paediatric laparoscopic procedures
Authors: Johnson PA , Johnson JC , Mardon AA
Published: November 2022

Introduction

We aimed to evaluate the da Vinci surgical system in its application for robotic-assisted laparoscopic surgery in paediatric patients.

Methods

A narrative review of the literature on the use of this technology was performed following ENTREQ guidelines using PubMed/Medline, EMBASE, and Google Scholar databases with no setting or language restrictions.

Results

A total of 16 publications were selected for inclusion. Although the literature on the accuracy and precision of this technology are encouraging, its use in paediatric patients are still in its early stages and has yet to be explored in great detail. In addition to the technical intricacies, training and learning curve, port placement complications, cost, we identified concerning shortcomings including its bulkiness and lack of force feedback, which lead to procedural injuries notably, tearing of muscles, blood vessels, and nerves, as well as surgical error. For both, we propose sensory haptic feedback systems, soft tissue model, image-guided or virtual reality simulation training to reduce these injury-related complications. However, this does not replace the necessity for “supervised trial and error” operation of the robotic system in surgical settings.

Conclusion

Innovations in educational training for robotic surgery include tele-presence surgeries and robotic tele- mentoring, whereby expert surgeons share the same surgical field of view and controls as the training surgeon. In spite of this, there are inevitable risks associated with training when training surgeons must practice through trial and error on real patients and an emphasis must be placed on apposite pre-procedural surgical training.

Take-home message

Though promising, the use of the Da Vinci robotic system in children is still emerging and thus warrants further evaluation, training, and development prior to its routine implementation for use.
P21 Textbook outcome following oesophagectomy for cancer: an international cohort study
Authors:   Oesophago-Gastric Anastomotic Audit (OGAA) Collaborative
Published: November 2022

Introduction

Although textbook outcome (TO) has been proposed as a tool for the assessment of oncological surgical care, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess TO in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 - December 2018. TO was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with TO, and results are presented as odds ratio (OR) and 95% confidence intervals (CI95%).

Results

Of 2,159 patients with oesophageal cancer, 39.7% achieved a TO. The outcome parameter ‘no major postoperative complication’ had greatest negative impact on a TO for patients with oesophageal cancer, compared to other TO parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of TO. Presence of 24-hour on-call rota for oesophageal surgeons (OR: 2.05, CI95%: 1.30–3.22, p=0.002) and radiology (OR: 1.54, CI95%: 1.05–2.24, p=0.027), total minimally invasive esophagectomies (OR: 1.63, CI95%: 1.27–2.08, p<0.001), and chest anastomosis above azygous (OR: 2.17, CI95%: 1.58–2.98, p<0.001) were independently associated with a significantly increased likelihood of TO.

Conclusion

TO is achieved in less than 40% of patients having oesophagectomy for cancer. Improvements in centralisation, hospital resources (i.e. daily 24-hour on-call esophagogastric surgeons and radiologists), access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve TO. Understanding how these individual parameters help improve quality of patient care should be the focus of future research.
O002 Diabetes-associated HLA donor genotypes and pancreas transplant outcomes
Authors: Owen RV , Counter C , Shaw JA , Wilson CH , White SA
Published: November 2022

Introduction

The genotypes HLA DR3/DR4, DR3/DR3, DR4/DR4 are associated with a predisposition to diabetes. This study evaluated UK recipient outcomes after pancreas transplantation from donors with a diabetes-associated genotypes.

Methods

Data on all UK pancreas transplants from 2004–2019 was obtained from the NHSBT-UK Registry, n=2,938. HLA-DR type was recorded for all organ donors. Re-transplants and those missing patient (PS) or graft (GS) survival were excluded, resulting in a final cohort of n=2,661. We further delineated our categories into SPK, PTA and PAK as a previous study suggested different recipient categories may be adversely affected. Univariate analyses were conducted using Kaplan-Meier plots and multi-variate analysis using Cox-regression models. Complications were analysed using chi-squared analyses.

Results

The majority of grafts were from donors not associated with diabetes genotypes (90.1%, n=2397) whereas 5.4%(n=145) came from HLA DR3/DR4 donors, 1.6%(n=43) from DR3/DR3 and (n=76)2.9% from DR4/DR4. Comparable outcomes for GS at 1yr (SPK p=0.980, PTA p=0.759, PAK p=0.244) and 3yrs (SPK p=0.708, PTA p=0.744, PAK p=0.275) and PS at 1yr (SPK p=0.553, PTA p=0.527, PAK p=0.756) and 3yrs (SPK p=0.728, PTA p=0.928, PAK p=0.424) were seen. Multivariate analysis also showed no statistically significant difference in GS (p=0.604, HR 1.041, 95%CI 0.895, 1.211) or PS (p=0.623, HR 1.045, 95%CI 0.876, 1.248). There were comparable complication rates.

Conclusion

This multicentre UK study has found comparable survival outcomes and complication rates within our donor-HLA-genotype groups. We do not believe that the presence or absence of a diabetes associated HLA-genotype influences outcomes for any category of pancreas transplant.

Take-home message

We do not believe that the presence or absence of a diabetes-associated HLA-genotype influences outcomes for any category of pancreas transplant.
O011 An analysis of cost effectiveness and clinical outcomes of elective abdominal aortic aneursym repair in a tertiary centre over one year
Authors: Songra L , Baker D , Davis M , Constantinou J , Hamilton H , Agu O , Hynes N
Published: November 2022

Introduction

Endovascular aneurysm repair (EVAR) is an alternative to open surgical repair (OSR) of abdominal aortic aneurysms (AAA) and has a superior short-term safety profile. However recent guidelines have questioned its long-term cost-effectiveness. We retrospectively compared EVAR, Fenestrated EVAR (FEVAR) and OSR of non-ruptured AAA in a tertiary centre over 12 months, to determine whether FEVAR represents an affordable, clinically efficacious option in aortic repair

Methods

Data was collected from the National Vascular Registry and hospital records.73 patients underwent primary elective AAA repair. Patients were followed up for one year post-operatively. The primary outcome was cost per QALY. Secondary outcomes included 30-day mortality and morbidity, aneurysm-related mortality, re-intervention rates, length of hospital stay and all-cause mortality at one year.

Results

Cost per QALY was calculated as £19134.75, £15408.00 and £12118.16 for FEVAR, EVAR and OSR respectively (FEVAR vs EVAR p= 0.438, FEVAR vs OSR p= 0.001, OSR vs EVAR p= 0.589) OSR was associated with a longer overall hospital and ITU stay, and significantly higher incidence of respiratory complications post-operatively compared to FEVAR and EVAR. FEVAR was associated with significantly higher operative costs, and higher re-intervention and readmission rates compared to EVAR and OSR. There was no significant difference between perioperative and one year mortality between the repair options.

Conclusion

FEVAR is more expensive than OSR but based on NICE willingness-to-pay thresholds, it still presents a viable alternative for aortic repair, when performed in specialist centres. However, long term data is required to make informed decisions on cost-effectiveness.

Take-home message

FEVAR represents a viable alternative for elective abdominal aortic repair. Long-term RCT data are required to make informed decisions on cost effectiveness
O014 Oxidised zirconium versus cobalt-chrome femoral heads in total hip arthroplasty: a multi-centre prospective double-blinded randomised controlled trial with 10-years follow-up
Authors: Kayani B , Baawa J , Fontalis A , Tahmassebi J , Wardle N , Middleton R , Hutchinson J , Haddad FS
Published: November 2022

Introduction

This study reports the ten-year polyethylene liner wear rates, incidence of osteolysis, clinical outcomes and complications of a three-arm, multicentre randomised controlled trial comparing Cobalt-Chrome (CoCr) and Oxidised Zirconium (OxZr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) versus highly cross-linked polyethylene(XLPE) liners in total hip arthroplasty (THA).

Methods

Patients undergoing THA from four institutions were prospectively randomised into three groups. Group A received a CoCrfemoral head and XLPE liner; Group B received an OxZrfemoral head and XLPE liner; and Group C received an OxZr femoral head and UHMWPE liner. Patients and observers recording study outcomes were blinded to the treatment groups at each follow-up interval. The outcomes of 262 study patients were analysed at ten years follow-up after THA.

Results

At ten years follow-up, increased linear wear rates were recorded in group C compared to group A (0.133 ± 0.21 mm/yr vs 0.031 ± 0.07 mm/yr respectively, p<0.001) and group B (0.133 ± 0.21 mm/yr vs 0.022 ± 0.05 mm/yr respectively, p<0.001). Patients in group C were associated with increased risk of osteolysis and aseptic loosening requiring revision surgery compared with group A (7/133 vs 0/133 respectively, p=0.007) and group B (7/133 vs 0/135 respectively, p=0.007).

Conclusion

The use of UHMWPE was associated with progressively increased annual liner wear rates after THA. At ten years follow-up, this translated to UHMWPE leading to an increased incidence of osteolysis and aseptic loosening requiring revision THA, compared with XLPE.

Take-home message

THA using XLPE liners is associated with improved long-term implant survivorship and reduced revision surgery compared with UHMWPE liners at long-term follow-up.
O021 Evaluating the impact of neurosurgical rotation experience in Africa on the interest and perception of medical students towards a career in neurosurgery: a continental, multi-centre, cross-sectional study
Authors: Ooi SZY , Dada OE , Bukenya GW , Kenfack YJ , Chi L , Ohonba E , Adeyemo E , Narain K , Awad AK , Barrie U , Sichimba D , Ogunfolaji O , Kitonga LM , Oriaku AJ , Bamimore MA , Okor DE , Rominiyi O
Published: November 2022

Introduction

Africa has the second-highest neurosurgical workforce deficit globally, and many medical students in Africa lack exposure to the field. This study aims to assess the impact of a neurosurgical rotation during medical school in shaping the perception and interest of students towards a career in neurosurgery.

Methods

This is a continental, multi-centre, cross-sectional study. A Google Form e-survey was disseminated to African clinical medical students between February 21st and March 20th, 2021. Data was analysed using descriptive statistics and adjusted logistic regression modelling.

Results

Data was received from 539 students in 30 African countries (n=30/54, 55.6%). The majority of participants were male (n=289/539, 53.6%) and were from Kenya (n=83/539, 15.4%). Most students had undertaken a clinical neurosurgery rotation (n=278/539, 51.6%); the majority reported a rotation length of four weeks or less (n=181/278, 65.1%). Students with clinical experience were less likely to pursue the specialty (p=0.02) and had a stronger perception that it is more difficult for women to pursue neurosurgery (p=0.0001) when compared to those without clinical experience. However, after adjusting for other factors, students with greater than four weeks of neurosurgical exposure were more likely to express a career interest in neurosurgery (odds ratio [OR]=1.75, p<0.04) and men were more likely to express interest in a neurosurgical career compared to women (OR=3.22, p<0.001).

Conclusion

Our findings support standardised, continent-wide, curriculum development, and advocacy supporting improved gender inclusivity in education and policy-making to improve the quality of neurosurgical exposure during medical school and tackle the workforce deficit across Africa.

Take-home message

A continent-wide, standardised curriculum guide to neurosurgical rotations, and advocacy for gender inclusivity in education and policy-making efforts across the African continent is required to shape the perception and interest of medical students towards a career in neurosurgery.