bluuebunny/crossref_metadata_2025 huggingface dataset:
Miniaturized fundus camera based on cross-polarization and in vivo verification
Authors: Yang Luyao , Zhao Qingliang
Published: July 2024

As an important part of clinical examination, fundus examination can reveal early symptoms of both eye and chronic physical diseases, thus helping doctors and automated screening to diagnose and treat in time. However, widely used portable fundus cameras are often disturbed by stray light, which seriously affects the quality of fundus imaging, extremely detrimental to the clinic. In this work, we have successfully built a miniaturized fundus camera based on the cross-polarization method, which simplifies the system design while guaranteeing high-quality imaging compared with other methods. The simulation results of the optical path and the imaging effect in vivo show that cross-polarization has a powerful effect on eliminating stray light. Our approach provides a new solution for the field of fundus photography and an application-level advance for the popularization of medical resources.
Influence of Wire Feeding Speed on the Morphology and Properties of Stainless Steel Laser Welding Joints
Authors: Liu Shuai , Luo Ziyi , Liu Weiqing , Wang Yuzheng , Cai Detao
Published: July 2024

Using laser filler wire welding technology, welded joints were produced at varying wire feeding speeds. The microstructure and mechanical attributes of these joints were then examined through optical metallography, scanning electron microscopy, universal tensile testing, and microhardness testing. It demonstrates that superior surface formation and defect-free welded joints can be achieved through the filling wire welding process. The main components are austenite and ferrite, with slightly varying morphology and content. Through the results of tensile tests and fracture microstructure scanning, when the rate of wire supply is 2.0 meters per minute, the tensile strength reaches 650 MPa. The second phase particles were discovered in the fracture scan. According to microhardness measurements, the overall hardness of the welded joints at different wire feeding speeds is higher than that of the base material.
An Improved Predictive Controller for PMSM based on Dual-Channel Feedback
Authors: Lu Junhao
Published: July 2024

High-performance and high-power-density DC servo drives of permanent magnet synchronous motors (PMSM) are applied to the military, especially in airborne optoelectronic pods, light mines, and launch turntables in the aerospace field. The above application scenarios require the volume of drivers to be smaller and have large power outputs. In the field of pods and light mines, high bandwidth and good tracking performance are required, especially in terms of steady-state accuracy. Since light mines are used for target tracking scanning, the errors at the end of the optical rotating mechanism are amplified tens or even hundreds of times after transmission through the line of sight to the target end. Therefore, the requirements for steady-state accuracy are extremely high. In this article, a predictive control method is proposed, using a sliding mode variable structure controller to make up for the error arising from system parameter changes in predictive control. Finally, a dual-channel rotary transformer feedback position coarse-fine combination algorithm method is studied to reduce the angular measurement error and further improve steady-state accuracy.
Study of LC oscillation based on excitation source of two-stage full-bridge structure
Authors: Hao Sirui , Wang Xuhong , Meng Qingke , Hu Shanchao
Published: July 2024

Nuclear magnetic resonance logging transmitting circuits must face the harsh operating environment of high voltage and high frequency. To reduce the voltage and current tolerated by the switching devices in the circuit and minimize the circuit loss, a high-frequency, high-voltage pulse transmitting circuit based on a two-stage full-bridge structure is designed in this paper. A new strategy for pulse excitation oscillation is proposed. The proposed strategy is based on the decision to end the excitation at the moment of peak voltage and the condition for limiting peak charging current (3.2). Finally, the circuit topology and excitation strategy proposed to achieve the overall optimal performance of sustained voltage oscillation with a peak voltage of 1180 V, precisely matching the transmitting frequency of 481 kHz and suppressing the charging current below 10 A.
Study on Optimization of Placement Method for Transmission Line Monitoring Devices Based on Probability of Meteorological Disasters
Authors: Zhang Guoqiang , Wang Jian , Jiang Wendong , Li Mengxuan , Liu Jinghua , Ren Shuai
Published: July 2024

To ensure the reliability and safety of the power grid system, it is of great significance to carry out electric meteorological monitoring for transmission channels. In this paper, a method for optimizing the placement of transmission line monitoring devices based on the probability of meteorological disasters is proposed. By considering the climatic characteristics near the transmission line, the probability of occurrence of adverse meteorological faults for each transmission tower in the transmission line is analyzed and calculated by using existing meteorological and GIS elevation data. Meanwhile, the historical failure data and voltage levels of transmission lines are combined to achieve the optimization of the installation position of monitoring devices in transmission channels. This method was applied to a 220 kV transmission line for practical analysis, achieving dense monitoring in areas with high failure rates and sparse monitoring in areas with low failure rates.
Voltage Control in Distributed Photovoltaic Power Distribution Networks Using Multi-Agent Deep Reinforcement Learning
Authors: Xin Peiqi , Wang Hongtao , Wang Haobo
Published: July 2024

This study introduces a unique method employing the Multi-Agent Deep Deterministic Policy Gradient (MADDPG), a sophisticated deep reinforcement learning algorithm, for efficient voltage control in photovoltaic (PV) power distribution networks. The algorithm’s design emphasizes minimizing the need for communication and effectively managing delays, which are pivotal in ensuring consistent and reliable control in environments with fluctuating renewable energy sources. In simulations using the IEEE-33 power distribution system, the research demonstrates the algorithm’s ability to ensure stable and efficient network functioning, even under varying environmental and load conditions. This highlights its potential as a robust solution for modern and renewable energy-integrated power systems.
Switching control method for collaborative robots based on hybrid Petri nets
Authors: Shang Yujia , Lu Tielin
Published: July 2024

Aiming at the different working conditions of the mixed production process of collaborative robots, three kinds of controllers with the structure of sliding mode controller, backstepping controller and feedback linearisation are designed respectively, and a control structure switching method based on Petri net is proposed. The method is able to achieve better control performance by switching into different control methods to realise the relevant work tasks (tracked motion trajectories) according to the different work tasks (tracked motion trajectories) to be accomplished by the collaborative robots.
Suspended garbage detection of transmission lines based on improved YOLOv8
Authors: Wang Sixing
Published: July 2024

The problem of garbage suspension in transmission lines is an important factor affecting the reliability of the power grid. With the application of artificial intelligence in the detection of abnormal objects in transmission lines, the detection efficiency, accuracy, and stability have been improved to a certain extent. However, the accuracy of detecting suspended garbage in transmission lines is relatively poor. This article uses an improved YOLOv8 algorithm for suspended garbage detection, replacing the original loss function with the SIoU loss function, which improves the iteration speed and detection progress of the model. In addition, the use of depthwise separable convolution instead of the original dilated convolution compensates for the problem of information loss when size objects may exist, greatly improving the model’s ability and accuracy in identifying suspended garbage quality and laying the foundation for improving the accuracy of garbage detection in transmission lines.
The Design and numerical simulation of a 3D-printed flexible capacitive pressure sensor with a composite structure
Authors: Chen Yike , Zhang Hongbo , Gao Yang , Yin Ruixue
Published: July 2024

Flexible pressure sensors are crucial for many areas, such as electronic skins, human motion, robot monitoring, and medical treatment. However, conventional manufacturing methods limit the speed and accuracy of manufacturing sensor dielectric layers. In this paper, a unique capacitive pressure sensor with a composite structure is introduced that can be fabricated by 3D printing technology. The structure, which has 3D hierarchical pyramids microstructures and porous substrate, can be directly fabricated by a DLP 3D printer. This allows flexible dielectric layers to be fabricated quickly while maintaining their superior performance. The dimension of the produced sensor is 10×10×4.5 mm3. The sensor’s design process, numerical simulation, and performance are provided and elucidated. The performance of the sensor is measured between 0 and 1 MPa. It has low hysteresis and high sensitivity (6.83 MPa−1 within the scope of 0 to 0.5 MPa and 2.56 MPa−1 within the scope of 0.5 to 1 MPa).
Model Establishment and Parameter Identification of Remotely Operated Vehicle (ROV)
Authors: Zhang Yelei , Yin Baoji , Jiao Huifeng , Zhang Jian , Yan Fei
Published: July 2024

To study the dynamic characteristics of remotely operated vehicle (ROV) underwater motion, a transformation matrix between the carrier coordinate system and the inertial coordinate system was established, and the rigid body dynamics model of the ROV was derived by using the Newton-Euler equation. According to the results of the ROV experimental prototype in this article, the dynamic model is simplified based on the force, motion characteristics, and structural characteristics. In the pool experiment, based on the propeller dynamic model, the least squares method was used to identify the parameters of the heading and vertical dynamic models, and through the experimental results under step control signals of different amplitudes, they were compared with the models under the same control signal. The output is subjected to error analysis. The experimental results show that the error between the theoretical value and the experimental value is small, verifying the accuracy of the ROV dynamics model established in this article.
Load voltage study of LCC-S type wireless energy transmission system based on phase shift control
Authors: Bao Pengfei , Xu Fei
Published: July 2024

When the light load is applied in an LCC-S type wireless power transmission (WPT) system, the system does not have constant voltage characteristics, which affects the normal use of power equipment. If a DC/DC converter is used to regulate the voltage at both ends of the load to keep it constant, it will increase the size and cost of the system, and the efficiency is also reduced. For this reason, in this paper, phase-shift control is carried out based on the LCC-S type WPT system, and the LCC-S resonant compensation network is first modeled and analyzed in terms of its working principle. Then, the principle of phase-shift control is analyzed, the relationship between the drive signal phase-shift angle and the load voltage in the phase-shift control is deduced, and finally, a simulation model is built in Matlab/Simulink to verify the correctness of the control strategy.
Study on the mathematical model of the novel drum worm pair
Authors: Li Shuangcen , Xiao Linglin
Published: July 2024

A lot of work is needed to investigate the design method of planar internal gear enveloping drum worm (PIGEDW). Firstly, based on the gear meshing theory, the meshing equation is deduced. Secondly, the PIGEDW mathematical model is established by MATLAB. Finally, the influence of the inclination angle of the generating plane on the meshing performance of PIGEDW is analyzed. The results show that appropriate changes in geometric parameters are beneficial in enhancing the performance of PIGEDW, which provides a way to optimize its design.
Utilizing wavelet packet decomposition to locate the damage of composite structures in strong-noise environment
Authors: Wang Minjie , Zhu Wujun , Xiang Yanxun
Published: July 2024

This paper proposes an approach for damage localization in a strong noise environment based on wavelet packet decomposition. Experiments were conducted to locate damage in composite structures to verify the method. The signal was decomposed by a wavelet packet, and the damage information was identified through wavelet packet energy ratio deviation, defined as the damage factor. The proposed method effectively localizes the damage and directly captures the original signal without the need to preprocess the strong noise signals. Additionally, it bypasses the complex process of extracting reflected signals, demonstrating substantial potential for detecting and identifying composite damage in noisy environments.
Research and Analysis of TC4 Titanium Alloy Cutting Based on Crystal Plasticity Theory
Authors: He Tao , Tang Yaxin , Wu Hongbing , Liu Yongyue , Chen Jindong
Published: July 2024

Based on the crystal plasticity theory, the changes in TC4 titanium alloy before and after cutting, especially the changes in cutting forces, chip temperature, morphology, and quality, were analyzed in this study. Initially, a polycrystalline plasticity model for the TC4 titanium alloy was established. Following that, a crystal plasticity polycrystal finite element cutting simulation model is developed to perform cutting simulations. This model represents the mechanical behavior of the micro grains of TC4 titanium alloy during the deformation and cutting processes. Further, it validates the internal grain plastic deformation and the effect on the metallography of TC4 titanium alloy before and after cutting. The results show a good consistency between experimental and simulation data. The grain size increases gradually from the center to the edge of the cutting area, with the phenomenon of equiaxed grains becoming more apparent, leading to the formation of elongated fine grains. During the cutting process, grains interlock and fracture, exhibiting strong anisotropy.
Analysis and Experimental Study of Puncture Leakage Characteristics of Pump-driven Fluid Loop Radiator
Authors: Huang Lei , Han Haiying , Yang Min , Che Bangxiang , Niu Chunyang , Wang Dewei , Zheng Hongyang , Yu Xingang
Published: July 2024

The radiator is a key component of the pump-driven fluid loop in the thermal management system of spacecraft, and it has a high probability of being penetrated by Micro-Meteoroid and Orbital Debris (MMOD). Therefore, for long-life manned spacecraft such as space stations, the study of the leakage characteristics of radiators after breakdown is an important work that needs to be solved urgently. In this paper, the leakage state characteristics of the emitter after leaking are analyzed, and a mathematical model is established to calculate the relationship between the aperture and the leakage volume rate. Finally, the accuracy of the mathematical model is verified by experiments.
Experimental Study on Mechanical Properties of Reinforcement under Low-Temperature Impact
Authors: Yang Fan , Pan Jiawen , Zhang Bochao
Published: July 2024

Ammonia is an important carrier of hydrogen energy, and the large-scale storage of liquid ammonia is the next trend of cryogenic energy storage. At present, the international mainstream liquid ammonia tank is generally about 50, 000 m3. The outer storage tanks generally adopt a metal structure, and the material applied for larger concrete full-capacity tanks is worth doing further research. Steel reinforcement bars (rebar) are an important construction material for full-capacity cryogenic energy storage tanks. The performance of rebar is an important index in the process of designing the strength of building structures. The factors affecting the properties of rebar are diverse, and reasonable control of each influencing factor can improve the performance of rebar used for liquid ammonia storage tanks. This paper carries out the study on the mechanical properties of the steel reinforcement bars from the concrete of the main container under low temperatures for storing liquid ammonia. Through experimental research on the failure of steel used in external tanks, it has been shown that temperature has a significant impact on the ductile-brittle transition. Further treatment can effectively prevent the brittleness of steel bars, improve the safety and reliability of storage tanks at low temperatures, and is of great significance for the design and construction of subsequent large liquid ammonia storage tanks.
Effect of Strontium Modification on Microstructure and Mechanical Property Al12SiCuMgNi Alloy in Squeeze Casting
Authors: Ji Kaiwen , Li Longfei , Liang Junning , Li Chunming , Zhao Xuesheng , Han Qinghua , Chen Lin , Zuo Lingli , Zhang Yang
Published: July 2024

The Al-Si series alloys, which have excellent fluidity and castability, are the most common aluminum material in the casting industry. However, the coarse eutectic Si phase with laminar morphology leads to the stress concentration of material and has a detrimental effect on the mechanical properties of aluminum alloy components. In this study, the Strontium (Sr) modifier was added to Al12SiCuMgNi alloy and the effect of Sr on microstructure and performance of Al12SiCuMgNi in squeeze casting was investigated. The experimental results show that the eutectic Si phase was well modified to fibrous morphology. Although the yield strength (YS) was leveled, the ultimate tensile strength (UTS) and elongation (EL) of the alloy were obviously enhanced after Sr addition. When the 0.012wt.% Sr was added to Al12SiCuMgNi alloy. The YS, UTS, and EL of alloys were up to 311 MPa, 401 MPa, and 3.4%, respectively. Moreover, the microstructure and performance of Al12SiCuMgNi alloy in the hot forging process were also compared to Al12SiCuMgNi alloy with and without Sr addition in squeeze casting. It is concluded that the Al12SiCuMgNi alloy in hot forging shows higher ductility (4.7%) and lower strength than Al12SiCuMgNi alloy in squeeze casting.
Direction-dependent bending resistance of 3D printed bio-inspired composites with asymmetric 3D articulated tiles
Authors: Nash Richard J , Li Yaning
Published: July 2024

Inspired by the protective armors in nature, composites with asymmetric 3D articulated tiles attached to a soft layer are designed and fabricated via a multi-material 3D printer. The bending resistance of the new designs are characterized via three-point bending experiments. Bending rigidity, strength, and final deflection of the designs are quantified and compared when loaded in two different in-plane and two different out-of-plane directions. It is found that in general, the designs with articulated tiles show direction-dependent bending behaviors with significantly increased bending rigidity, strength, and deflection to final failure in certain loading directions, as is attributed to the asymmetric tile articulation (asymmetric about the mid-plane of tiles) and an interesting sliding-induced auxetic effect. Analytical, numerical, and experimental analyses are conducted to unveil the underlying mechanisms.
Harnessing the potential: exploring development opportunities and charting strategic pathways for China’s enhanced engagement in international blue carbon cooperation
Authors: Zhang Zhijun , Mao Zhengkai , Wang Jinpeng
Published: July 2024

In light of the urgent need to combat climate change and attain carbon neutrality, the development of blue carbon has emerged as a pivotal strategy for the global community. This approach offers significant potential for both mitigating and adapting to the impacts of climate change. As a result, international collaboration on blue carbon initiatives has become a focal point in the worldwide response to the climate crisis. China, blessed with extensive blue carbon resources, recognizes the development of these ecosystems as a critical component in its efforts to make a substantial contribution to the global endeavor to curb climate change and achieve sustainable environmental goals. This article offers a comprehensive analysis of China’s opportunities and challenges in international blue carbon collaboration. Despite its vast potential, China faces significant hurdles, including the degradation of blue carbon ecosystems, a delayed start in implementing blue carbon practices, and inconsistencies in the blue carbon standard system. To enhance its participation in global blue carbon initiatives, China should pursue several key strategies, including preserving and restoring its blue carbon ecosystems, strengthening domestic protection and application mechanisms, promoting the construction of an international blue carbon system, establishing a scientific cooperation platform to facilitate capacity building and technology transfer and advocating for an international blue carbon market trading mechanism. By prioritizing these key areas, China can simultaneously foster domestic blue carbon conservation and development while solidifying its role as a pivotal contributor to global climate change mitigation efforts.
A quantitative explanation for the large impacts of El Niño during its decaying stage
Authors: Ji Xuanliang , Feng Juan , Li Jianping , Chen Xingrong , Wang Chunzai
Published: July 2024

This study examines the comparative atmospheric circulation and tropical sea surface temperature (SST) relationships during the developing and decaying stages of El Niño from a meridional structure standpoint. Results indicate a transition in the variability of the first two modes of the Hadley circulation (HC) during these stages, with the first mode exhibiting a larger explained variance in the decaying stage. The regime change in HC variability corresponds to underlying anomalous SST distributions, as confirmed by sensitive experiments. Quantitative assessment reveals the HC-SST response amplitudes are approximately two times stronger during the decaying stage compared to the developing stage. Employing the Kuo–Eliassen (KE) equation, diabatic heating anomalies during the decaying stage explain the difference in air-sea response intensity between the two stages. Diabatic heating variations are identified as the primary contributor to amplification or reduction of air-sea response intensity during the respective El Niño stages, providing insights into the different air-sea processes throughout the El Niño lifespan.
Towards revealing intrinsic vortex-core states in Fe-based superconductors through statistical discovery
Authors: Guo Yueming , Miao Hu , Zou Qiang , Fu Mingming , Sefat Athena S , Lupini Andrew R , Kalinin Sergei V , Gai Zheng
Published: July 2024

In type-II superconductors, electronic states within magnetic vortices hold crucial information about the paring mechanism and can reveal non-trivial topology. While scanning tunneling microscopy/spectroscopy (STM/S) is a powerful tool for imaging superconducting vortices, it is challenging to isolate the intrinsic electronic properties from extrinsic effects like subsurface defects and disorders. Here we combine STM/STS with basic machine learning to develop a method for screening out the vortices pinned by embedded disorder in iron-based superconductors. Through a principal component analysis of large STS data within vortices, we find that the vortex-core states in Ba(Fe0.96Ni0.04)2As2 start to split into two categories at certain magnetic field strengths, reflecting vortices with and without pinning by subsurface defects or disorders. Our machine-learning analysis provides an unbiased approach to reveal intrinsic vortex-core states in novel superconductors and shed light on ongoing puzzles in the possible emergence of a Majorana zero mode.
Green and chemical synthesis of CuO nanoparticles: comparative reproductive toxicity evaluation at various phases and in offsprings
Authors: Naz Sania , Ali Joham Sarfraz , Zia Muhammad , Mahmood Asif , Masry Waheed Al , Masud Haleema , Latif Muhammad
Published: July 2024

Metallic nanoparticles (NPs) are used in various biomedical applications due to their widespread utility. This study compares the reproductive toxicity of chemically synthesized CuO NPs (ChemSyn CuO NPs) and green synthesized CuO NPs (GrSyn CuO NPs) in rats and their offspring during mating, pregnancy, and lactation phases. CuO NPs were synthesized using Rhus punjabensis extract and their physio-morphological characteristics were illustrated. Both approaches showed pure and spherical NPs with an average size of 14.94 ± 0.6 and 19.02 ± 0.9 nm. Orally administered NPs at a dose of 100 mg kg−1 body weight of ChemSyn NPs reduced peroxidase activity by 38% and glutathione levels by 36%. In female rats treated with ChemSyn NPs, TBARS were increased by 11%, and total protein increased by 54%. The offspring did not show notable differences in their antioxidant status, but reactive substances in female offspring increased by 32%, and total protein content decreased by 57%. Genotoxicity of 2.72% and 1.9% tail DNA was observed in male and female pups, respectively. Testosterone levels were reduced in male parents, and progesterone concentration increased in female parents in a dose-dependent manner. In contrast, GrSyn NPs were more biocompatible, and thyroid hormones in the parents showed less variation. No obvious alterations were observed in the histological patterns of the gonads. These findings indicate that GrSyn NPs can be explored as drug carriers and contrast agents in vivo.
Electrospun PAN/PANI/CNT scaffolds and electrical pulses: a pathway to stem cell-derived nerve regeneration
Authors: Fakhraei Khosravieh Zahra , Nekounam Houra , Asgari Fatemeh , Haghighipour Nooshin
Published: July 2024

Biocompatible polymer-based scaffolds hold great promise for neural repair, especially when they are coupled with electrostimulation to induce neural differentiation. In this study, a combination of polyacrylonitrile/polyaniline (PAN/PANI) and Carbon Nanotubes (CNTs) were used to fabricate three different biomimetic electrospun scaffolds (samples 1, 2 and 3 containing 0.26 wt%, 1 wt% and 2 wt% of CNTs, respectively). These scaffolds underwent thorough characterization for assessing electroconductivity, tensile strength, wettability, degradability, swelling, XRD, and FTIR data. Notably, scanning electron microscopy (SEM) images revealed a three-dimensional scaffold morphology with aligned fibers ranging from 60 nm to 292 nm in diameter. To comprehensively investigate the impact of electrical stimulation on the nervous differentiation of the stem cells seeded on these scaffolds, cell morphology and adhesion were assessed based on SEM images. Additionally, scaffold biocompatibility was studied through MTT assay. Importantly, Real-Time PCR results indicated the expression of neural markers—Nestin, β-tubulin III, and MAP2—by the cells cultured on these samples. In comparison with the control group, samples 1 and 2 exhibited significant increases in Nestin marker expression, indicating early stages of neuronal differentiation, while β-tubulin III expression was significantly reduced and MAP2 expression remained statistically unchanged. In contrast, sample 3 did not display a statistically significant upturn in Nestin maker expression, while showcasing remarkable increases in the expression of both MAP2 and β-tubulin III, as markers of the end stages of differentiation, leading to postmitotic neurons. These results could be attributed to the higher electroconductivity of S3 compared to other samples. Our findings highlight the biomimetic potential of the prepared scaffolds for neural repair, illustrating their effectiveness in guiding stem cell differentiation toward a neural lineage.
Massive macroscopic quantum effect detected
Authors: Dumé Isabelle
Published: July 2024

Researchers in the US and Canada have detected an effect known as quantum Barkhausen noise for the first time.
Laser light induces massive magnetic moments
Authors: Dumé Isabelle
Published: July 2024

Pulses of laser light can cause any material – including insulators – to develop a relatively large magnetic moment.
Excitation of thorium-229 brings a working nuclear clock closer
Authors: Starckx Senne
Published: July 2024

A nuclear clock based on thorium-229 is one step closer after researchers in Germany and Austria have shown that they can put nuclei of the isotope into a low-lying metastable state.
US DIII-D National Fusion Facility resumes operations
Authors: Banks Michael
Published: July 2024

The DIII-D National Fusion Facility in San Diego has completed eight months of upgrades that will help researchers to control and study fusion plasmas.
Birth of the boffin?
Authors: Hill John
Published: July 2024

A response to the letter by Alan Neal (May 2024), who speculated on the origin of the term “boffin” – a term that the Institute of Physics wants journalists to avoid using to describe scientists.
The power of diversity
Authors: Durrani Matin
Published: July 2024

Keith Burnett, the current president of the Institute of Physics, talks to Matin Durrani about his career in physics, the value of universities to a modern economy and how the IOP’s new strategy seeks to make physics open to all.
Deep probabilistic direction prediction in 3D with applications to directional dark matter detectors
Authors: Ghrear Majd , Sadowski Peter , Vahsen Sven E
Published: July 2024

We present the first method to probabilistically predict 3D direction in a deep neural network model. The probabilistic predictions are modeled as a heteroscedastic von Mises-Fisher distribution on the sphere

S

2

, giving a simple way to quantify aleatoric uncertainty. This approach generalizes the cosine distance loss which is a special case of our loss function when the uncertainty is assumed to be uniform across samples. We develop approximations required to make the likelihood function and gradient calculations stable. The method is applied to the task of predicting the 3D directions of electrons, the most complex signal in a class of experimental particle physics detectors designed to demonstrate the particle nature of dark matter and study solar neutrinos. Using simulated Monte Carlo data, the initial direction of recoiling electrons is inferred from their tortuous trajectories, as captured by the 3D detectors. For

40

keV electrons in a 70% He 30% CO2 gas mixture at STP, the new approach achieves a mean cosine distance of 0.104 (26∘) compared to 0.556 (64∘) achieved by a non-machine learning algorithm. We show that the model is well-calibrated and accuracy can be increased further by removing samples with high predicted uncertainty. This advancement in probabilistic 3D directional learning could increase the sensitivity of directional dark matter detectors.
Introduction
Authors: Badano Gabriele , Nuti Alasia
Published: July 2024

This chapter introduces the main argument and the structure of the book. It explains how the normative account of liberal democratic self-defence developed in the book differs from existing approaches to liberal democratic erosion that can be found in civil society and in the scholarly literature. The chapter explains the appeal of John Rawls’s framework of political liberalism, which provides the ground of the arguments advanced in the book. It also introduces the reader to the key notions of that framework, and it outlines the many contributions that the book makes to debates over liberal democratic self-defence as well as discussions over political liberalism.
Why Exclude Unreasonable Persons? On Reasonable Ideas as the Core Truths of Political Liberalism
Authors: Badano Gabriele , Nuti Alasia
Published: July 2024

This chapter is the first of two that focus on the reasonable/unreasonable distinction, which is the ground on which any Rawlsian theory of containment rests. However, this distinction is heavily criticized as too exclusionary for its role in Rawls’s account of public reason, according to which justifications for fundamental political decisions should only be directed to reasonable persons. This chapter provides an original answer to these critiques. Some political liberals reply by trying to demonstrate that the exclusion of the unreasonable from the constituency of public reason can actually be justified to them. In line with the project of amending political liberalism in a more political direction, one crucial implication of our rejection of this reply is that we should accept that under any regime, there will always be groups that are coerced into obedience without any justification. Other political liberals offer what they take to be the correct justification for exclusion, e.g., that it is necessary to build relationships of civic friendship. In so doing, however, those theorists endorse deeper premises than the basic political ideas defining reasonableness, which should instead be treated as the bedrock of political liberal theory. In contrast, we explain that the exclusion of the unreasonable should simply be taken as an implication of an intrinsically appealing political ideal that represents the core truth of political liberalism—that of establishing together a cooperative system among free and equal persons that is justifiable to all who themselves care about acceptability to others and are open to disagreement.
Socratic Questionnaires
Authors: Hansen Nat , Francis Kathryn B , Greening Hamish
Published: July 2024

When experimental participants are given the chance to reflect and revise their initial judgments in a dynamic conversational context, do their responses to philosophical scenarios differ from responses to those same scenarios presented in a traditional static survey? In three experiments we find no consistent evidence that responses differ in these different formats. This aligns with recent findings that manipulations of reflectiveness have no effect on participants’ judgments about philosophical scenarios. Although we did not find a consistent quantitative effect of format (conversation vs. static survey), conversational experiments still provide qualitative insights into debates about how participants are understanding (or misunderstanding) the scenarios they read in experimental studies, and whether they are replacing difficult questions with questions that are more easily answered. We argue that conversational experiments—“Socratic questionnaires”—help show what is going on “under the hood” of traditional survey designs in the experimental investigation of philosophical questions.
Oleanane-type saponins from Lysimachia laxa Baudo and their antibacterial activities
Authors: Luyen Nguyen Thi , Dat Nguyen Tien , Giang Do Hoang , Thuy Nguyen Thi Kim , Tai Bui Huu , Huong Phan Thi Thanh , Quynh Le Thi Phuong , Thuy Duong Thi , Park SeonJu , Nhiem Nguyen Xuan
Published: July 2024

Seven new oleanane-type triterpene saponins, lysimaponins A-G, were isolated from aerial parts of Lysimachia laxa Baudo. Their chemical structures have been elucidated by analysis of spectroscopic and chemical methods. All compounds were evaluated for their antibacterial effects against Microcystis aeruginosa, Vibrio parahaemolyticus, V. harveyi, V. vulinificus, V. cholerae, and V. alginolyticus. All compounds showed potent antibacterial activities against the cyanobacteria M. aeruginosa with IC50 values ranging from 14.4 ± 1.2 to 35.3 ± 2.2 µg/mL. Compounds 1, 2, 4-7 inhibited V. parahaemolyticus with MIC values ranging from 64 to 256 µg/mL. The results suggested that saponins from L. laxa could be potential anti-cyanobacteria agents.
Highly defended nudibranchs “escape” to visually distinct background habitats
Authors: van den Berg Cedric P , Santon Matteo , Endler John A , Cheney Karen L
Published: July 2024

The “escape and radiate” hypothesis predicts that once species have evolved aposematism, defended species can utilize more visually diverse visual backgrounds as they “escape” the need to be well camouflaged. This enables species to explore new ecological niches, resulting in increased diversification rates. To test this hypothesis “escape” component, we examined whether the background habitats of 12 nudibranch mollusk species differed among species depending on the presence and strength of chemical defenses. We obtained a rich array of color pattern statistics using quantitative color pattern analysis to analyze backgrounds viewed through the eyes of a potential predator (triggerfish, Rhinecanthus aculeatus). Color pattern analysis was done at viewing distances simulating an escalating predation sequence. We identified 4 latent factors comprising 17 noncorrelated color pattern parameters, which captured the among-species variability associated with differences in chemical defenses. We found that chemically defended species, indeed, were found on visually distinct backgrounds with increased color and luminance contrast, independent of viewing distance. However, we found no evidence for increased among-species background diversity coinciding with the presence and strength of chemical defenses. Our results agree with the “escape and radiate” hypothesis, suggesting that potent chemical defenses in Dorid nudibranchs coincide with spatiochromatic differences of visual background habitats perceived by potential predators.
524 Outcomes From Preoperative Risk Scoring for Emergency Laparotomy
Authors: Gangakhedkar S , Holmes M , Gani J , Pockney P
Published: July 2024

Aim

Risk scoring systems can be used to predict outcome, facilitate perioperative decision making and guide management in emergency laparotomy (EL). This study aims to evaluate the differences in outcome between EL patients who were prospectively risk assessed and those who were not.

Method

A retrospective study was conducted on all 782 patients aged over 18 years who underwent EL at four Australian hospitals between 1 January 2018 and 31 December 2019. Data recorded included demographics, preoperative risk assessment, case urgency, involvement of anaesthetic and intensive care consultants, critical care bed requirement, mortality, and discharge destination. NELA scores were retrospectively calculated for all patients.

Results

209 patients had been preoperatively risk assessed, with a mean NELA score of 16.45%, compared to 8.72% for those who were not preoperatively risk assessed. They tended towards a higher ASA score, were booked as a higher urgency operation, and were more likely to receive consultant led care by anaesthetics and intensivists. Postoperatively these patients had increased critical care bed utilisation, 30-day mortality was 14.4% compared to 5.8%, and by 365 days mortality rose to 24.9% compared to 13.8%.

Conclusions

Use of preoperative risk prediction scores does not in itself reduce risk of mortality. In a health system that does not mandate formal preoperative risk assessment, it appears that clinicians use preoperative risk assessment tools when they perceive risk to be higher, rather than as a routine part of emergency laparotomy care.
862 An Overview of Laparoscopic Surgical Training Modalities – How Does Augmented Reality Simulation Compare?
Authors: Swealem A , Ludick C , Rawaf D , Street E , Van Flute J
Published: July 2024

Aim

Compare different types of laparoscopic training modalities and assess how AR compares to the education system using the apprenticeship model on patients and alternative training modalities, including human cadavers, box trainers, and virtual reality (VR) simulators.

AR is a novel introduction to laparoscopic surgical training and can superimpose digital images and physical models with the unique advantage of combining visual realism with true-to-life haptic feedback.

Method

31 papers were systematically reviewed, and the findings were compiled. Results for the available products and the technology as an educational modality were evaluated.

Results

Studies reported increased speed of learning, improved ability to multitask, procedural accuracy, hand-eye coordination and bimanual operation in a reduced practice time and increased success rate with AR in healthcare education. One of the limitations of AR it doesn’t reflect the non-technical skills required in the operation.

Compared with other modalities AR provided faster skill acquisition and was widely preferred, except when compared to the cadaver model for straight laparoscopic colorectal skills acquisition.

AR tends to have a higher initial purchasing cost but does not require the costly specialist facilities or services that cadaver or animal models do, 150 trusts in the NHS preliminary data show an estimated annual saving of £117m.

Conclusions

AR simulation has the potential to become the new gold standard for laparoscopic surgical training, and beyond, pending further development of literature to increase knowledge of the technology and its capabilities, on top of technological evolution to increase clinical realism.
1231 Using Novel Technologies and Innovative Theatre Utilisation Procedures to More Than Triple Operating Theatre Output
Authors: Hatfield T , Nwodo C , Sahota B
Published: July 2024

Aim

In the current climate of extended waiting lists and increasing demands on theatre time and personnel, efficiency gains are vital in shaping the future of surgical practice. We have utilised novel surgical technology to drive massive increases in throughput for one of the most commonly performed procedures worldwide (tonsillectomies).

Method

Use of the BiZactTM device, a vessel sealing bipolar instrument, has been shown in our trust and worldwide to be safe and offer greater efficiency. We combined this with a conveyor-belt style theatre arrangement - with a second team preparing and anaesthetising the following patient simultaneously, and changes to anaesthetic and post-op procedures to maximise productivity.

Results

Contrasting the GIRFT recommended 3 adult half day tonsillectomy list, we were able to safely perform 10 adult tonsillectomies in one session, with no change in expected post-operative complication rates. Average time recorded on the theatre system was 10m:00s per patient, with the average time-on-tonsil just 2m:59s. There was 1 patient who presented post-operatively with secondary haemorrhage that was managed conservatively.

Conclusions

The implementation of efficient technology, combined with innovative theatre procedural technique, short lasting anaesthetics and reduced post operative observation time allowed the half day list capacity to be increased by 333%. Complication rates in this case, and in our wider use of this technique (n=103), have been within normal range, whilst allowing greatly increased efficiency and rapid reduction of local waiting lists. Lessons learned from this conveyor-belt style practice have wide ranging potential applications across specialties that will drive efficient future practice.
141 Simulation Training: The Impact on the Confidence and Preparedness of Novice Otolaryngology ST3 Registrars
Authors: Rai A , Patel P , Khan H , Shukla S , Mehtani N , Acharya V , Tolley N
Published: July 2024

Aim

This research employs the HoloLens2™ and a variety of models to evaluate the impact on the confidence and preparedness of ST3 trainees following their engagement in simulated otolaryngology cases.

Method

A total of 29 ST3 trainees engaged in ten 1-hour long simulation stations across a span of two days. The participants engaged in both technical and non-technical skills within elective, emergency, and ward-based scenarios. Questionnaires were used to document self-reported confidence and preparedness before and after each simulation. Primary outcomes included change in trainee confidence and preparedness pre- and post-station.

Results

The participants reported a significant increase in confidence (p<0.001) and preparedness (p<0.001) after all stations. The greatest improvements in comparison to all other stations were self-preparedness in the rigid bronchoscopy station and self-confidence in the sphenopalatine artery (SPA) ligation station. A significant improvement in self-confidence (p<0.001) and self-preparedness (p<0.0001) was observed after the non-technical HoloLensTM session.

Conclusions

The use of Otolaryngology simulation stations improved confidence and preparedness of managing common ENT presentations in the ward, elective, and emergency settings for ENT ST3 trainees. This approach serves as a valuable supplement to the conventional surgical apprenticeship, facilitating the acquisition of both technical and non-technical skills. The implementation of mixed reality technology creates an immersive environment to develop trainees’ non-technical skills. However, future work is required to assess the impact on the long-term benefits of trainee skill retention and clinical proficiency.
559 Can Poller Screws Decrease Pain Relief in Femoral Fractures?
Authors: Bradshaw F , Eisner A , Zhang J , Brown A , Wakefield E , Krkovic M
Published: July 2024

Aim

Poller screws, used alongside intramedullary (IM) nails for femoral shaft fractures, aim to expedite healing and minimize complications by enhancing fracture stability and controlling IM nail insertion. Despite their benefits, the impact of poller screws on post-operative pain is understudied. This retrospective cohort study aimed to compare opioid medication needs in femoral shaft fractures managed with IM nails with and without poller screws.

Method

Between January 2015 and December 2022, a retrospective analysis was conducted on femoral shaft fractures treated at a major trauma centre. Patients primarily treated with IM nails were included. Patient and operation notes, along with radiographs, identified poller screw utilization and categorized screw generation. Opioid medication data, converted to "coverage" (days) and "strength" (morphine milligrams equivalent or MME), was collected. Two-tailed independent samples T-tests compared patients treated with (n=43) and without poller screws (n=364).

Results

Second-generation poller screws significantly reduced opioid strength requirements in the first post-operative year (603.6 vs. 1711.6 MME, p=0.03), except the first month. However, no significant difference was observed in the number of days with opioid prescriptions throughout the first post-operative year for each poller screw generation.

Conclusions

This study highlights the potential of poller screws in reducing post-operative pain in femoral fractures. Future endeavors aim to use a larger patient sample, but these results signify the promise of poller screws in mitigating post-operative pain in IM-treated femoral fractures.