bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization Analysis of the Wheel Hub Dynamic Balancing Machine Based on Particle Swarm Optimization
Authors: Cao Juan , Cao Yuan
Published: February 2024

The vibration supporting rod of a wheel hub dynamic balancing machine is affected by the alternating dynamic load, and its vibration characteristics have a direct impact on the accuracy of measurements. To solve this problem, first, a particle swarm optimization algorithm (PSO) algorithm is proposed to optimize the dynamic stiffness of the vibration supporting rod. According to the actual material selection, the creep risk of the rod is reduced. Second, three schemes for improving the structure of hub balancing machines are put forward and compared. The displacement response and stress response of scheme A are increased by 30% and 20%, respectively, over those of the original equipment. The displacement response and stress response of scheme C are increased by 31% and 22%, respectively, which is a significant improvement. Schemes A and C are acceptable, but a strong first-mode response remains due to assembly variation.
Simulation Study on the Performance of Ultrasonic Pulse-Echo Detector for Ice Thickness Identification
Authors: Zhang Yanxin , Zhang Hongjian , Liu Yifan , Xiong Jianjun , Zhao Zhao , Ran Lin , Yi Xian
Published: February 2024

In-flight icing detectors are important for the flight safety of aircraft. Detectors based on ultrasonic pulse-echo can be used for detecting ice thickness. To study the influencing factors of ultrasonic pulse-echo detection performance, a simulation model of elastic wave-piezoelectric coupling was established, which was used to analyze the influence of different types of piezoelectric ceramics, matching layers with different acoustic impedances, and different substrate materials on ultrasonic pulse-echo signals. It was found that when aluminum is used as the substrate material, the ultrasonic echo signal has a higher signal-to-noise ratio. Furthermore, the influence of aluminum substrate materials with different thicknesses on ultrasonic pulse-echo was analyzed. The ice thickness can be identified by measuring the time of flight between the aluminum-ice interface echo and the ice-air interface echo. The results indicate that when the thickness of the aluminum substrate is 25mm, the upper detection limit of ice layer thickness can reach about 10mm. Therefore, the detection upper limit of ice layer thickness can be extended by appropriately increasing the thickness of the aluminum substrate material.
Inclination Build Rate of a Point-The-Bit Rotary-Steerable Tool
Authors: Wang Shuangning , Tang Ming , He Shiming , Ye Han
Published: February 2024

The combination of a rotary-steerable system (RSS) and power screws has become the main drilling tool for the efficient exploration and development of unconventional oil and gas. However, the application of point-the-bit (POB) rotary-steerable tools in directional drilling subjects spindle bearings to continuous alternating stress, which can lead to fatigue failure. In this study, numerical analysis and simulation are employed to guide the engineering application of rotary-steerable tools, particularly in the field of oil and gas exploitation. The structural composition and steering principles of rotary-steerable tools are analyzed. The influence of the structural parameters of the spindle on the deflection capacity of the tool is analyzed, and the optimal structural parameters are selected. Based on the results, the recommended distances between the various components of the tool could be obtained. Moreover, the maximum deflection capacity increases with torque when the WOB (weight-on-bit) is constant. Similarly, at constant torque, the maximum deflection capacity increases with the WOB. Overall, the WOB has a greater influence on the maximum deflection capacity than torque. To ensure the safe operation of the spindle, the WOB and torque must be within 200 kN and 20 kN·m, respectively. The findings of this study provide valuable insights into the safe application of POB rotary-steerable tools.
Vibration Response Analysis of a Time-varying Stiffness Wheel with Contrate Gear under Unbalanced Excitation
Authors: Xue Beirao , Man Jixin , Zuo Yanfeng , Yan Wengao
Published: February 2024

The vibration and response of multi-contact interface micro-motion time-varying stiffness wheel are analyzed, and the nonlinear vibration response characteristics caused by the unbalance force of multi-contact interface contrate gear face of a gas turbine rotor are studied. Firstly, the local sliding model of dry friction-damped contact is extended to establish a holistic and local unified sliding model. The equivalent stiffness and damping of the damping device are calculated by means of the equivalent linearization method and the first harmonic balance method. Finally, the finite element model of multi-contact contrate gear rotor wheel is established to analyze the influence of different unbalanced masses on vibration response under nonlinear frictional contact. The results show that the response caused by the unbalance mass of multi-contact interface wheel with contrate gear is mainly radial response, and the peak value of resonance response increases with the increase of unbalance force.
Research on Icing Classification Method Based on Wind Tunnel Test with Double Impact Surface Probe
Authors: Liu Wenfeng , Huang Xiong , Ge Junfeng , Luo Huan
Published: February 2024

Facing supercooled large water droplet environment, an effective ice detection method is a prerequisite to implement the avoidance strategy and get out of the icing environment of SLD as soon as possible. Fiber-optic icing sensors were arranged on the double impact surface probe. The probe was used for icing wind tunnel test. Different machine learning algorithms were used to establish the classification method of icing conditions based on multi-sensor ice thickness information fusion. An appropriate algorithm was selected for the classification method to detect icing conditions. The icing classification method based on SVM could effectively distinguish the conventional water droplet icing condition from the SLD icing condition, and it has significant potential on aviation industry application.
Research on Vibration Response of Shrouded Blades Based on Contact State
Authors: Man Jixin , Xue Beirao , Bian Xiangde
Published: February 2024

The shrouded is widely used in vibration reduction of turbine blades. In this study, the damping characteristics of the shrouded blade in gas turbine were studied. Firstly, a finite element model of the shrouded blade was established, and the full set of blades was reduced to a single sector based on the principle of cyclic symmetry. The contact state of the contact surface of the blade at different interference and speeds was calculated based on the displacement extraction method. Secondly, a microslip friction contact model was established based on the contact state of the contact surface. The nonlinear vibration response of shrouded blades was calculated based on the harmonic balance method. The results indicate that the shrouded has excellent vibration reduction performance. The interference and rotational speed of the blade will affect the damping efficiency.
The Crack Generation Algorithm of Underwater Bridge Based on Improved Generative Adversarial Network
Authors: Gu Yeyang , Yin Ling , Chen Haifeng , Song Jialei , Zhang Fei
Published: February 2024

To address the challenge of obtaining underwater bridge crack images for bridge defect detection, this paper proposes an enhanced CycleGAN algorithm based on a generative adversarial network. Within the encoder-decoder architecture, two key enhancements have been introduced. First, to prevent the loss of information at different scales during training, residual connections with 1x1 convolutional kernels have been added. Second, to prioritize useful feature information during model training, the CBAM attention mechanism has been incorporated. Experimental results demonstrate that the improved model significantly enhances performance, with a 29% increase in the FID index, as well as a 9% improvement in PSNR and a 7% improvement in SSIM.
Analysis of Repetitive Positioning Accuracy of Parallel Mechanisms Based on Monte Carlo Method
Authors: Liang Fengchao , Huang Gang , Tan Shuang , Lin Zhe , Shi Zhicheng
Published: February 2024

Based on the inverse kinematics model of the Stewart parallel mechanism, a motion platform pose error model was constructed through differential transformation. The error model shows that the motion platform pose error comes from the length error of 6 struts and the position error of 12 hinge centers, with a total of 42 error terms. Monte Carlo simulation was used to analyze the effects of struts length error on the pose error of the moving platform. The results show that when the length error of the struts follows a normal distribution, the posture error of the moving platform approximately follows a normal distribution. Monte Carlo simulation is a highly effective error analysis method that can analyze the error distribution pattern of the mechanism before processing and assembly, which provides a method for error analysis of Stewart parallel mechanisms.
Study on the Blasting Effect of Radial Uncoupled Parameters on Limestone
Authors: Liu Erping
Published: February 2024

To analyze the influence of radial decoupling parameters on the blasting effect of limestone, finite element analysis was established using ANSYS/ls-dyna to analyze the effects of different radial decoupling coefficients and different media on blasting. Research has found that limestone has more cracks and more pronounced cracking when air is uncoupled. Under the condition of air decoupling, the stress waves in the rock mass are more concentrated and have higher energy, while under the condition of water decoupling, the stress waves in the rock mass diffuse faster, have a larger range of action, and have lower energy. Reasonably increasing the radial decoupling coefficient can effectively reduce damage around the borehole. For limestone formations, it is recommended to use an air decoupling method during construction, with a radial decoupling coefficient kd=2.0 for the borehole.
Wakefields excited in the FCC-ee collimation system
Authors: Behtouei M. , Carideo E. , Zobov M. , Migliorati M.
Published: February 2024

The purpose of this paper is to calculate the longitudinal
and transverse wakefields of the FCC collimators using the
electromagnetic codes ECHO3D and IW2D. We cross-checked our results
using CST particle studio for long bunches, and found them to be in
good agreement. The obtained results show that the collimators give
one of the highest contributions to the overall FCC-ee wake
potentials. In particular, using the code PyHEADTAIL, we have found
that the geometric contribution of the collimators' wakefield
reduces significantly the transverse mode coupling instability
threshold. Therefore, it is imperative to explore and implement
solutions that effectively mitigate this wakefield source.
Editorial announcements and information — ICFA Beam Dynamics Newsletter No. 85
Authors: Cai Yunhai , Biagini Maria Enrica
Published: February 2024

This is a general information article of the ICFA Beam
Dynamics Newsletter No. 85. It contains foreword from the
Editor-in-Chief and the issue editor, a workshop and conference
report section, a recent Ph.D. thesis section, a forthcoming beam
dynamics events section, and a section of announcements from the
beam dynamics panel.
Luminosity performance of SuperKEKB
Authors: Zhou D. , Ohmi K. , Funakoshi Y. , Ohnishi Y.
Published: February 2024

Since April 2020, the SuperKEKB has been operating with the
crab waist scheme. The luminosity record achieved in June 2022 was
4.71 × 1034 cm-2 s-1, which overtook
its predecessor KEKB by more than a factor of 2. The beam-beam
interaction plays a key role in causing vertical blowup and
consequently limiting the luminosity performance of SuperKEKB. In
this paper, we examine luminosity tunings under the influence of
beam-beam effects and review the luminosity performance of SuperKEKB
with the crab-waist operation from 2020 to 2022.
Collimation simulations for the FCC-ee
Authors: Abramov A. , Broggi G. , Bruce R. , Carlier F. , Hofer M. , Iadarola G. , Nevay L.J. , Pieloni T. , Rakic M. , Redaelli S. , White S.M.
Published: February 2024

The collimation system of the Future Circular Collider,
operating with leptons (FCC-ee), must protect not only the
experiments against backgrounds, but also the machine itself from
beam losses. With a 17.8 MJ stored energy of the electron and
positron beams, they are highly destructive, and beam losses risk to
cause damage or a quench of superconducting elements. Accurate
collimation simulation tools and models are needed to design the
collimation system and optimize the collimation performance,
including magnetic tracking, synchrotron radiation and optics
tapering, as well as particle-matter interactions. As no existing
code was found that incorporated all these features, a new
simulation software tool has been developed. The tool is based on an
interface between a particle tracking engine, pyAT or Xtrack, and a
Monte-Carlo particle-matter interaction engine for collimator
scattering, BDSIM, which is based on Geant4. Results from a
simulation of edge scattering from a beam halo collimator in the
FCC-ee are presented to demonstrate the capabilities of the tool.
Development of a digital low-level RF system for the STCF
Authors: Xie Chunjie , Xiong Ziyu , Zhang Ailin , Zhou Zeran , Luo Qing
Published: February 2024

With the development of particle physics, higher
requirements are put forward for the brightness and energy of the
collider. A new collider — the Super Tau-Charm Facility (STCF) —
is under study in China. To meet the high acquirement of the quality
of the beam, a digital low-level RF (LLRF) system that achieves high
stability plays a critical role as a part of the microwave system of
Linacs. This paper introduces the design of a digital LLRF system
that works in the S-band (2856 MHz) as required by Linacs of the
STCF. The system architecture and hardware design as well as the
control algorithms and software design are discussed and tested. The
system includes a signal source, a frequency synthesis system and an
IF signal processor. The phase noise of the signal source is as low
as 20.3 fs, and the low-level IF signal processor adopts amplitude
and phase control by a PI-type controller. They jointly realize
ultra-low phase noise signal output. The table experiments show that
the short-term amplitude and phase stability of the system is better
than 0.01% and 0.01°, respectively. The beam experiments
show that the closed-loop phase stability in the cavity is about
0.1°. The results prove that the LLRF system meets the
requirement of the STCF.
The injector design for STCF in China
Authors: Zhang Ailin , Xu Xin , Pei Guoxi , Xu Lechen , Xiong Zijian , Peng Haiping , Luo Qing
Published: February 2024

A new generation electron-positron collider — the Super
Tau-Charm Facility (STCF) — has been proposed in China. The STCF
will have a luminosity greater than 0.5 × 1035 cm-2 s-1 and a center-of-mass energy range of 2 to
7 GeV. Injectors are an essential component of circular
colliders, particularly positron generating systems. The proposed
STCF injector, Linac, accelerates both electrons and positrons from
1.0 GeV up to 3.5 GeV with a high intensity of 1.5 nC per bunch
for Tau-Charm research. An injector with a high-energy
electron-target positron production system was designed. The design
baseline of the STCF injector Linac, positron source, and damping
ring have been carried out in this paper.
Associations of long-term exposure to ambient sulfur dioxide, carbon monoxide, ozone, and benzene with risk of incident chronic kidney disease in the UK
Authors: Zhang Feifei , Liu Yuhao , Yang Chao , Wang Fulin , Zhang Luxia
Published: February 2024

Limited studies have examined associations of gaseous air pollutants exposure with chronic kidney disease (CKD) in Europe. This study aimed to calculate the relationships between long-term exposure to ambient sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and benzene and CKD in the UK. We included 502 369 participants from the UK biobank cohort. Associations of SO2, CO, O3, and benzene with CKD were estimated using Cox proportional hazards model. The shape of the exposure-response association between each air pollutant and CKD was then depicted using the shape constrained health impact function. We finally estimated the incidence of CKD attributable to each air pollutant by linking the constructed exposure-response association to the 2019 Global Burden of Disease data. Our results suggested SO2, high O3 days (daily max 8 hr O3 concentration > 120 µg m−3), CO, and benzene were positively associated with the risk of incident CKD. The hazard ratios (HRs) of CKD for SO2, CO, and benzene were 1.058 (95% CI: 1.039–1.078), 1.003 (95% CI: 1.001–1.005), and 1.619 (1.433–1.829) for every 1 μg m−3 increase in the concentration, respectively. For high O3 days, the HR of CKD was 1.044 (95% CI: 1.032–1.056) for every 1 d increase, but correlation to O3 concentration did not reach the statistical significance in the time-varying model. The risk of CKD increased non-linearly with increasing SO2, high O3 days, and CO, and linearly with increasing benzene. We estimated that 7.9%, 16.0%, 8.0% of incident CKD cases in the UK in 2021 could be attributed to exposure to SO2, O3, and benzene, respectively. We concluded that exposure to SO2, CO, O3, and benzene were all positively associated with increased CKD risk. Our findings highlight the importance of considering air pollution while making strategies targeting on CKD management.
Impact of marine carbon removal on atmospheric CO2
Authors: Nuterman Roman , Jochum Markus
Published: February 2024

A computer simulation of Earth’s climate is used to study if marine carbon removal will lead to a reduced atmospheric carbon dioxide concentration, and if there are potential secondary impacts on marine life and chemistry. We find that for stationary carbon removal plants the ocean cannot supply sufficient carbon rich water to allow a meaningful reduction of atmospheric CO2. This also means that outside the location of carbon removal there is no noticeable impact on plankton concentrations. It can be speculated that putting carbon removal plants on ships would lead to a significant increase in removal efficiency, although the engineering and energy aspects of this approach would need to be investigated.
Average spectral density of multiparametric Gaussian ensembles of complex matrices
Authors: Gayas Ansari Mohd , Shukla Pragya
Published: February 2024

A statistical description of part of a many body system often requires a non-Hermitian random matrix ensemble with nature and strength of randomness sensitive to underlying system conditions. For the ensemble to be a good description of the system, the ensemble parameters must be determined from the system parameters. This in turn makes its necessary to analyze a wide range of multi-parametric ensembles with different kinds of matrix elements distributions. The spectral statistics of such ensembles is not only system-dependent but also non-ergodic as well as non-‘stationary’. A change in system conditions can cause a change in the ensemble parameters resulting an evolution of the ensemble density and it is not sufficient to know the statistics for a given set of system conditions. This motivates us to theoretically analyze a multiparametric evolution of the ensemble averaged spectral density of a multiparametric Gaussian ensemble on the complex plane. Our analysis reveals the existence of an evolutionary route common to the ensembles belonging to same global constraint class and thereby derives a complexity parameter dependent formulation of the spectral density for the non-equilibrium regime of the spectral statistics, away from Ginibre equilibrium limit.
Road performance analysis due to Sayung Industrial Park development
Authors: Sirait R D , Sumabrata R J , Anumasta N T
Published: February 2024

This study aims to analyze the impact of Sayung Industrial Park development to the surrounding road network. The study merely relies on available secondary data, including recent transport study in Semarang Raya, trip rate, and previous research related on industrial area occupancy growth. Road performance in the terms of degree of saturation and travel speed are analyzed using a simplified four-step model using CUBE software. The results show that in 2023, assuming 50% occupancy of the industrial park, the average travel speed decreases by 8.5% and the average degree of saturation increases by 18.7%. While in 2030, assuming 100% occupancy, the road performance is worsened, the average travel speed decreases by 46.4% and the average degree of saturation increases by 45.5%. A new additional lane in each direction on Semarang–Demak main corridor is simulated to anticipate the full operational of Sayung Industrial Park in the future. The result shows an improvement on road performance.
Accessibility and Land Use Effect of Residential Area with Different TOD Typology to Value Creation
Authors: Arliani Vani , Sjafruddin Ade , Santoso Idwan , Winarso Haryo
Published: February 2024

TOD (Transit Oriented Development) is the planning design focusing on integrated transportation and land use in an area with certain radii. There are many transits node which is being designed as TOD, which varies into many typologies. Indication of TOD measurement from TOD ideal, can be measure from accessibility factor and land use factor. There is an indication that each TOD area will give different output (value creation) related to accessibility and land use function. Many studies states about the TOD in different city. where this paper will analyse many areas within the same city. The method is analysing the area into TOD index using AHP, then measuring the value creation with summation of real land and building priceThen analyse the correlation between TOD index and value creation. The study case locations is in Lebak Bulus, Dukuh Atas and Kelapa Gading. The identification of value creation will be useful as an input to the urban planners or policy makers for designing more targeted strategies. The discoveries made in comparative context differ from those made in prior studies. This paper is thus believed to make a new contribution to the existing TOD categorized with additional input related to value creation inside.
Spatial Analysis to Determine Black Spot Area in Kulon Progo Regency, Yogyakarta, Indonesia
Authors: Pratama W A , Mahmudah N
Published: February 2024

Nowadays the number of traffic accidents increase due to the surging volume of road traffic. The efforts to reduce number of accidents is important, especially to identify the location and causes the accidents. Therefore, this study aims to identify black spot areas, which are areas with a high concentration of traffic accidents, in Kulon Progo Regency in Yogyakarta, Indonesia. The method used is spatial analysis by combining analysis of traffic accident data and geographic information system (GIS) data using ArcGIS software. The study focused on provincial road consist of primary collector 2 and 3, as well as national road segments. The analysis of accident data allowed the identification of hotspots where accidents occur most frequently. Hotspot analysis methods such as Local Statistic Analysis and Kernel Density Estimation were used to assess the spatial patterns and clustering of accidents. The study found that the black spot area in Kulon Progo Regency was mainly concentrated on the National Road Segment, with fewer occurrences on the Provincial Road with function of Primary Collector 2 and minimal presence on the Primary Collector 3 Road Segment. This result can be used to develop strategies to mitigate accidents and improve road safety in the area.
The willingness-to-walk to access public transit in Indonesia
Authors: Hadid M , Tufail D N , Hidayat A , Khofifah B S
Published: February 2024

In order to support the implementation of public transportation, an understanding of people’s interest in walking is essential. The farther people’s walking distance means public transportation will have a larger catchment area. This study aims to get parameters that can be used to improve walking distance in Balikpapan (Indonesia). Data collection in this study was carried out through stated preference surveys to 800 respondents divided into 400 motorcycle users and 400 car users. The data were analysed using the Binary Logistics Regression Analysis method, and the result shows that the respondent’s walking distance was 300 meters with a probability of 47% (motorcycle) and 59% (car). The result shows that two aspects significantly influence the willingness to walk, comfort and aesthetics. So, the strategies that are prepared to increase willingness to walk can be started by providing street furniture to support the comfort aspect and planting trees and plants to add aesthetic value.
Leaf habit and plant architecture integrate whole-plant economics and contextualize trait–climate associations within ecologically diverse genus Rhododendron
Authors: Medeiros Juliana S , Burns Jean H , Dowrey Callie , Duong Fiona , Speroff Sarah
Published: February 2024

Plant resource strategies negotiate a trade-off between fast growth and stress resistance, characterized by specific leaf area (SLA). How SLA relates to leaf structure and function or plant climate associations remains open for debate, and leaf habit and plant architecture may alter the costs versus benefits of individual traits. We used phylogenetic canonical correspondence analysis and phylogenetic least squares to understand the relationship of anatomy and gas exchange to published data on root, wood, architectural and leaf economics traits and climate. Leaf anatomy was structured by leaf habit and carbon to nitrogen ratio was a better predictor of gas exchange than SLA. We found significant correspondence of leaf anatomy with branch architecture and wood traits, gas exchange corresponded with climate, while leaf economics corresponded with climate, architecture, wood and root traits. Species from the most seasonal climates had the highest trait–climate correspondence, and different aspects of economics and anatomy reflected leaf carbon uptake versus water use. Our study using phylogenetic comparative methods including plant architecture and leaf habit provides insight into the mechanism of whole-plant functional coordination and contextualizes individual traits in relation to climate, demonstrating the evolutionary and ecological relevance of trait–trait correlations within a genus with high biodiversity.
Utility and Comparative Performance of Current Artificial Intelligence Large Language Models as Postoperative Medical Support Chatbots in Aesthetic Surgery
Authors: Abi-Rafeh Jad , Henry Nader , Xu Hong Hao , Bassiri-Tehrani Brian , Arezki Adel , Kazan Roy , Gilardino Mirko S , Nahai Foad
Published: February 2024

Background

Large language models (LLMs) have revolutionized the way plastic surgeons and their patients can access and leverage artificial intelligence (AI).

Objectives

The present study aims to compare the performance of 2 current publicly available and patient-accessible LLMs in the potential application of AI as postoperative medical support chatbots in an aesthetic surgeon's practice.

Methods

Twenty-two simulated postoperative patient presentations following aesthetic breast plastic surgery were devised and expert-validated. Complications varied in their latency within the postoperative period, as well as urgency of required medical attention. In response to each patient-reported presentation, Open AI's ChatGPT and Google's Bard, in their unmodified and freely available versions, were objectively assessed for their comparative accuracy in generating an appropriate differential diagnosis, most-likely diagnosis, suggested medical disposition, treatments or interventions to begin from home, and/or red flag signs/symptoms indicating deterioration.

Results

ChatGPT cumulatively and significantly outperformed Bard across all objective assessment metrics examined (66% vs 55%, respectively; P < .05). Accuracy in generating an appropriate differential diagnosis was 61% for ChatGPT vs 57% for Bard (P = .45). ChatGPT asked an average of 9.2 questions on history vs Bard’s 6.8 questions (P < .001), with accuracies of 91% vs 68% reporting the most-likely diagnosis, respectively (P < .01). Appropriate medical dispositions were suggested with accuracies of 50% by ChatGPT vs 41% by Bard (P = .40); appropriate home interventions/treatments with accuracies of 59% vs 55% (P = .94), and red flag signs/symptoms with accuracies of 79% vs 54% (P < .01), respectively. Detailed and comparative performance breakdowns according to complication latency and urgency are presented.

Conclusions

ChatGPT represents the superior LLM for the potential application of AI technology in postoperative medical support chatbots. Imperfect performance and limitations discussed may guide the necessary refinement to facilitate adoption.
Cyclophosphamide activates ferroptosis-induced dysfunction of Leydig cells via SMAD2 pathway
Authors: Liao Senlin , Wei Cun , Wei Guanyang , Liang Haoyu , Peng Fan , Zhao Lei , Li Ziguang , Liu Cundong , Zhou Qizhao
Published: February 2024

Cyclophosphamide (CP) is a widely used chemotherapeutic drug and immunosuppressant in the clinic, and the hypoandrogenism caused by CP is receiving more attention. Some studies found that ferroptosis is a new mechanism of cell death closely related to chemotherapeutic drugs and plays a key role in regulating reproductive injuries. The purpose of this study is to explore ferroptosis’ role in testicular Leydig cell dysfunction and molecular mechanisms relating to it. In this study, the level of ferroptosis in the mouse model of testicular Leydig cell dysfunction induced by CP was significantly increased and further affected testosterone synthesis. The ferroptosis inhibitors ferrostatin-1 (Fer-1) and iron chelator deferoxamine (DFO) can improve injury induced by CP. The results of immunohistochemistry showed that Fer-1 and DFO could improve the structural disorder of seminiferous tubules and the decrease of the number of Leydig cells in testicular tissue induced by CP. Immunofluorescence and western blot confirmed that Fer-1 and DFO could improve the expression of key enzymes in testosterone synthesis. The activation of SMAD family member 2 (Smad2)/cyclin-dependent kinase inhibitor 1A (Cdkn1a) pathway can improve the ferroptosis of Leydig cells induced by CP and protect the function of Leydig cells. By inhibiting the Smad2/Cdkn1a signal pathway, CP can regulate ferroptosis, resulting in testicular Leydig cell dysfunction. In this study, CP-induced hypoandrogenism is explained theoretically and a potential therapeutic strategy is provided.
Topical steroid withdrawal: a survey of UK dermatologists’ attitudes
Authors: Barlow Richard , Proctor Andrew , Moss Celia
Published: February 2024

The term topical steroid withdrawal (TSW) refers to a condition widely discussed on social media, but rarely mentioned in the medical literature. It typically involves a patient with chronic eczema who abruptly discontinues topical corticosteroids (TCS) believing they are ineffective and damaging. Symptoms include an acute eruption, worse than the previous eczema, of painful erythema followed by oozing, crusting, desquamation and sometimes prolonged systemic weakness. Patients self-diagnose and often avoid healthcare professionals who dismiss the diagnosis and persist in offering TCS, leaving them unsupported. We analysed 121 responses to a survey of UK dermatologists’ attitudes to TSW. Views on aetiology included relapsed eczema, erythroderma and a social construct. A total of 88.4% (107/121) agreed that TSW needs better understanding and more research. Respondents earlier in their careers are more cautious than senior respondents about prescribing TCS long term because of TSW, suggesting a trend that might lead to better understanding, communication and management.
Populismo constituyente, democracia y promesas incumplidas: el caso de la Convención Constitucional Chilena (2021-2022)Constituent populism, democracy, and failed promises: The case of the Chilean Constitutional Convention (2021-2022)
Authors: Issacharoff Samuel , Verdugo Sergio
Published: February 2024

Mechanisms of popular participation, such as constitutional conventions and citizen assemblies, emerge as a near-universal canon of every political discussion on how constitutions should change. This article offers a cautionary approach to the way these participatory mechanisms work in constitution-making. In democratic contexts including populist narratives and representative institutions functioning in flawed ways, constitution-making can fail not simply despite the existence of participatory mechanisms but in part because of them. We identify two types of failures. First, the authoritarian failure, which consists of constitution-making processes that lead to authoritarian outcomes or become part of democratic backsliding or abusive processes. Second, the activation failure, by which constitutions are not passed. We claim that this later failure can likely occur when reforms attempt to bypass established, functioning institutional actors, whatever their flaws, and use a comparative approach to the Chilean Constitutional Convention (2021-2022) as an example.
Efficacy of cefoperazone/sulbactam for ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteraemia and the factors associated with poor outcomes
Authors: Chen Rou-Zhen , Lu Po-Liang , Yang Tsung-Ying , Lin Shang-Yi , Tang Hung-Jen , Chang Feng-Yee , Yang Ya-Sung , Chiang Tsung-Ta , Wang Fu-Der , Wu Ting-Shu , Shie Shian-Sen , Ho Mao-Wang , Liu Jien-Wei , Shi Zhi-Yuan , Chou Chia-Hui , Chuang Yin-Ching
Published: February 2024

Objective

We aimed to assess the efficacy of cefoperazone/sulbactam (CPZ/SUL) in extended-spectrum β-lactamase (ESBL)-producing Enterobacterales infections and identify factors influencing outcomes.

Methods

This retrospective multicentre study was conducted in Taiwan (January 2015 to December 2020) and examined the efficacy of CPZ/SUL treatment in ESBL-producing Enterobacterales bacteraemia. The minimum inhibitory concentrations (MICs) were determined using agar dilution; ESBL/AmpC genes were detected using polymerase chain reaction. The primary outcome was clinical success, whereas the secondary outcome was 30-day mortality. Clinical success was defined as the complete resolution of clinical signs and symptoms of K. pneumoniae or E. coli infection, with no evidence of persistent or recurrent bacteraemia. The factors influencing outcomes were identified using a multivariate analysis.

Results

CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia, with a 30-day mortality rate of 9.1% (10/110). Among 110 ESBL-producing isolates, a high clinical success rate was observed at an MIC of ≤32/32 mg/L. Multivariate analysis revealed that a Charlson comorbidity index (CCI) of ≥6 was associated with lower clinical success [odds ratio (OR): 5.80, 95% confidence interval (CI): 1.15–29.14, P = 0.033]. High Sequential Organ Failure Assessment scores (≥6) were significantly associated with increased 30-day mortality (OR: 14.34, 95% CI: 1.45–141.82, P = 0.023).

Discussion

CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia. Treatment success was evident when the CPZ and SUL MIC was ≤32/32 mg/L. Comorbidities (CCI ≥6) were associated with lower clinical success, while disease severity (Sequential Organ Failure Assessment score ≥6) correlated with higher mortality.
Term Neonate Born With Right Upper Extremity Skin Necrosis at Birth: A Case Report
Authors: Siddappa Ashajyothi M , Shaik Likhita , Slusher Tina , Gayken Jon , Bjorklund Ashley
Published: February 2024

Congenital skin and soft tissue necrosis is a rare condition associated with significant morbidity and mortality in neonates. The authors treated a neonate born with significant skin necrosis of the right forearm. The case report is followed by a literature review and discussion of previously published reports of neonatal skin necrosis. A term female neonate was admitted to our hospital at 24 h of age for skin necrosis of the right forearm with sloughing and edema below the right elbow and contractures of her fingers. Topical treatment with cleansing and antibiotic application was initiated. The LUNA florescent microangiography showed superficial perfusion defects in the arm and dorsum of the hand along with overt ischemia over the dorsal aspect of the forearm. She was treated with intravenous antibiotics following a sepsis evaluation. Subsequently, she developed hypotension treated with fluid boluses, dopamine, and stress dose steroids. Concerns of wound infection and sepsis led to debridement of the necrotic area within the first 24 h post-admission. Wet-to-dry dressing changes using Vashe wound solution were begun postoperatively.; followed by placement of Integra on postoperative day-of-life (DOL) 7; dressing takedown on DOL 12; and autografting of the right hand and forearm with disarticulation of the 4th distal interphalangeal joints and right 5th distal interphalangeal transection on DOL 24. Postoperative dressing care was continued during the remainder of the hospital stay, she remained stable without any further complications and was discharged home on DOL 34 with outpatient clinic follow-up.
An improved pure quasi-P-wave equation for complex anisotropic media
Authors: Zhang Pingmin , Yao Gang , Zheng Qingqing , Fang Xinyu , Wu Di
Published: February 2024

An accurate pure qP-wave equation in transverse isotropic (TI) media and its efficient and stable implementation are valuable for seismic imaging and inversion. Owing to the complexity of the qP-wave phase velocity expression in anisotropic media, it is difficult to construct such a pure qP-wave equation. In this paper, we combine the Taylor expansion and scalar operator methods to formulate an efficient and stable pure qP-wave equation in TI media. First, the Taylor expansion method is used to convert the square-root term into a fractional term in the qP-wave phase velocity expression. We further improve the approximation accuracy of the resulting equation by a correction technique. Then, the scalar operator is applied to scalarize the equivalent form of the fractional term in the approximated dispersion equation, deriving a simple and easy-to-implement pure qP-wave equation. We use the optical flow method to compute the direction of wave propagation, which improves the calculation accuracy of the scalar operators. Numerical experiments with representative models demonstrate that the new method has higher accuracy and better adaptability to models with strong anisotropy, complex structure, and rapid variation of the tilt angle than previous methods.
A rare case of invasive endometriosis causing intestinal obstruction
Authors: Thirumurthy Sathish K , Mohammed Mahsheena
Published: February 2024

A 35-year-old woman presented to the emergency department with severe right iliac fossa pain with features of subacute intestinal obstruction and recurrent episodes of similar pain in the past. CT scan showed a mass with fluid collection with no trace of the appendix in the right iliac fossa. The patient was taken up for a diagnostic laparoscopy and proceeded. Operative findings were that of a mass in the lumen of the terminal ileum just 6 inches from the ileocaecal junction. Normal pelvis with normal uterus and ovaries. The patient underwent a laparoscopic resection of the terminal ileum and limited resection of the ascending colon with an ileo-colic anastomosis. The patient recovered well and was discharged. The biopsy was reported as invasive endometriosis involving the muscularis layer of the terminal ileum with stricture of the terminal ileum with transmural inflammation. The case is being presented for the rarity of invasive endometriosis causing bowel obstruction with a normal pelvis.
(018) Predictors of the Conduct of Nerve Sparing During Radical Prostatectomy
Authors: Thorogood SL , Liso N , Eastham J , Laudone V , Mulhall JP , Flores JM
Published: February 2024

Introduction

The association between nerve-sparing (NS) status at the time of radical prostatectomy (RP) and functional outcomes is well described; however, our profession lacks insight as to whether patient factors such as age and baseline erectile function influence surgeon behavior when it comes to nerve-sparing during RP.

Objective

We analyzed predictors associated with bilateral nerve damage/resection at the time of RP.

Methods

The study included patients who underwent RP with surgeon-reported NS scoring. The NS outcome of the right and left sides were independently scored between 1-4: 1 = completely preserved, 2 = partially preserved, 3 = partially damaged, and 4 = completely resected; scores of 1 or 2 indicate nerve-sparing and scores of 3 or 4 indicate non-nerve-sparing. We classified overall NS status as bilateral, unilateral, or not-spared. Demographics, ED-related comorbidities, pre-RP digital rectal exam (DRE), most recent prostate biopsy (bx) results, and pre-RP IIEF Erectile Function Domain (EFD) were analyzed. Pre-RP prostate MRI was used to define prostate volume (PV). EFD score < 24 defined non-functional erections. We created a multivariable (MV) model to define predictors of poorer NS status. The model included patient age, pre-RP EFD, PV, PSA, DRE, noted possible extracapsular extension (ECE) on pre-RP MRI, number of positive bx cores, and predominant Gleason (G) score on bx.

Results

3805 men met inclusion criteria. Median age was 64 (57, 67) years. Median pre-RP EFD score was 26 (15, 30); 41% had a pre-RP EFD score < 24. Median PV and PSA were 35 (27, 47) mL and 5.7 (4.2, 8.4) ng/dL, respectively. 64% had a normal pre-RP DRE. Median total bx cores 12 (9, 14). Median positive bx cores 4 (2, 7). Distribution of bx pathology: 17% G6, 64% G7, 10% G8, 8% G9, <1% G10. 65% had predominant G3 and 34% G4 pathology. 26% of MRI reports noted some degree of suspicion for ECE. NS status at RP: bilateral (69%), unilateral (20%), non-spared (11%). Median NS score was 3 (2, 4). On MV analysis, abnormal DRE, number of positive bx cores, and predominance of G4 were predictive of non-NS surgery. Most notably, the non-oncological factors – older patient age and a pre-RP EFD < 24 – were also predictive of non-NS surgery (Table).

Conclusions

While patient age and baseline erectile function (EF) are not necessarily predictors of a patient’s interest in preserving EF, these non-oncologic factors were identified as predictors of non-NS surgery in this analysis. Surgeons should define the individual patient’s sexual function goals prior to RP.

Disclosure

No.
(028) The Emerging Role of Telehealth in Sexual Medicine: A Survey of Patient Attitudes
Authors: Naeem T , Saffati G , Kassab J , Lipshultz LI , Khera M
Published: February 2024

Introduction

The COVID-19 pandemic brought with it an increase of healthcare interactions on an electronic interface, but a return to in-person interactions has left many questions open regarding the future utility and viability thereof. Urologic care, and particularly sexual health, frequently involves sensitive issues and understanding patients’ attitudes is imperative to determine how to incorporate telemedicine in the future.

Objective

This study seeks to characterize patients’ overall perspective on telehealth services in a sexual medicine setting to identify patient preferences and satisfaction with the use of telehealth services.

Methods

An electronic survey was sent through REDCap to patients who had at least one telehealth visit with a provider in our tertiary referral center since the start of the COVID-19 pandemic. The accrued patient cohort was sent a 15-question four-pronged survey assessing the purpose of the visit, the patient-provider relationship and communication, the perceived quality of care, and the patient’s overall satisfaction on a 5-point Likert scale. Descriptive statistical analysis was done using REDCap.

Results

We surveyed 4071 patients and received 771 (18.9%) responses. Of those who replied, 470 (61%) were seen for hypogonadism, 216 (28%) for erectile dysfunction, 50 (6.5%) for infertility, and 35 (4.5%) for Peyronie’s. A majority of patients (78.4%) ‘moderately’ or ‘strongly’ agreed that they are able to maintain a physician-patient relationship, are comfortable with telehealth use for new and follow-up visits alike and perceive a comparable quality of care when averaged across all questions in these sections. 613 (79.5%) of patients reported being ‘somewhat’ or ‘very’ satisfied with their telehealth visits and 513 (66.6%) patients would prefer a telehealth visit over an in-person in the future.

Conclusions

The results of this study indicate that patients are generally satisfied with telehealth visits, and it would likely be in the best interest for physicians and their patients to increasingly adopt telehealth solutions. The data further suggests that patients with certain diagnoses are less likely to prefer telehealth than others, though a more rigorous statistical analysis is needed once additional patient responses are received.

Disclosure

Any of the authors act as a consultant, employee or shareholder of an industry for: Consultant for AbbVie, Marius, Tolmar, Endo, Petros, Boston Scientific, Coloplast Investor: Sprout.
(061) Analysis of BMP4 and GREM1 as Targets of SHH Signaling and Downstream Regulators of the Collagen Axis in the Penis
Authors: Deng J , Martin S , Ohlander S , Harrington D , Stupp S , Mcvary K , Podlasek C
Published: February 2024

Introduction

Cavernous nerve (CN) injury caused by prostatectomy and diabetes, initiates a remodeling process (smooth muscle apoptosis and increased collagen) in the corpora cavernosa of the penis of patients and animal models that is an underlying cause of erectile dysfunction (ED). The Sonic hedgehog (SHH) pathway plays an essential role in the response of the penis to denervation, as collagen increases with SHH inhibition and decreases with SHH treatment. Part of the mechanism of how SHH impacts collagen may involve bone morphogenetic protein four (BMP4) and GREMLIN (GREM1). Microarray analysis identified increased GREM1 (BMP4 antagonist) in corpora cavernosa of ED patients and SHH is a regulator of GREM1 in the limb bud.

Objective

We will examine the relationship between SHH, BMP4, GREM1 and collagen in penis of ED patients and rat models of CN injury, SHH inhibition, and SHH, BMP4 and GREM1 treatment.

Methods

Corpora cavernosa of Peyronie’s (control), prostatectomy and diabetic ED patients was obtained (n=26). Adult Sprague Dawley rats (n=90) underwent either: 1. CN crush (1-7 days) or sham control, 2. CN injury and BMP4, GREM1 or MSA (control) protein treatment via Affi-Gel beads or peptide amphiphile (PA) for 14 days, 3. 5E1 SHH inhibitor, IgG and PBS (controls), or SHH protein treatment for 2-4 days. Immunohistochemical and western analysis for BMP-4 and GREM1, and collagen analysis by hydroxyproline and trichrome stain were performed.

Results

BMP4 and GREM1 proteins were identified in corpora cavernosal smooth muscle of prostatectomy, diabetic and Peyronie’s patients, and in rat penis, sympathetic nerve fibers, perineurium, blood vessels, and urethra. Collagen decreased 25.4% in rats with CN injury and BMP4 PA treatment (p=0.02) and increased 61.3% with CN injury and GREM1 treatment (p=0.005). Trichrome showed increased collagen in rats treated with GREM1. BMP4 increased smooth muscle. Western identified increased BMP4 and GREM1 in corpora cavernosa of prostatectomy and diabetic patients, and after CN injury (1-2 days) in our rat model. Localization of BMP4 and GREM1 changed with SHH inhibition. SHH treatment increased BMP4 and GREM1. Aging did not impact BMP4 and GREM1 localization.

Conclusions

BMP4 and GREM1 are downstream targets of SHH that impact collagen and may be useful in collaboration with SHH to prevent penile remodeling and ED. Better understanding of penile remodeling and how fibrosis occurs is essential for development of novel therapies for ED.

Disclosure

No.