bluuebunny/crossref_metadata_2025 huggingface dataset:
Kalman Filter-based Vibration State Estimation and Optimal Control of a Special Vehicle
Authors: Zhang Bowen , Zhang Ming , Zhou Yunbo
Published: June 2024

Take a certain type of special vehicle as the research object, establish the four-degree-of-freedom suspension vibration time-domain simulation model of the semi-vehicle, and use the Kalman filter algorithm for the vibration state of the vehicle in the driving process. By designing the Kalman observer of the linear suspension system, the state estimation of the vertical displacement and vertical acceleration of the front and rear suspensions and the body of the vehicle travelling on the uneven road surface is carried out, and the simulation analysis of the estimation effect is carried out, and the simulation results show that: the algorithm is able to estimate the relevant parameters of the vehicle vibration more accurately under the random road surface of E-level. Based on the state estimation value, a linear-quadratic optimal control method is adopted for the active control of suspension, which provides a basis for the design and optimal control of active suspension for subsequent special vehicles.
Analysis on the Precooler Outlet Compensation Pipe Rupture of Civil Aircraft
Authors: Du Nannan
Published: June 2024

This paper focused on the rupture problem of precooler outlet compensation pipe of civil aircraft, the design concerning was discussed. Based on the design proposal, aging mechanical from two aspects of temperature and high velocity sand dust flow were calculated and tested. Root cause of pipe rupture is identified and the result shows silicon rubber could not suffer high temperature up to 250 ℃ and velocity up to 150 m/s.
The Influence of Parameters and Load on the Spin Angle of Multilayer Strand Wire Rope
Authors: Wang Siqi , Cao Xuyang , Wang Dianlong , Xu Zhihe
Published: June 2024

The spin characteristics of multi-layer strand wire ropes can reduce the control accuracy of the crane lifting system, resulting in the crane being unable to meet the high-precision operation requirements. An object of this paper is to know about the influence of different parameters on the spin characteristics of multi-layer strand wire ropes. This article first theoretically analyzes the effects of wire rope twist angle, wire diameter, material, and load on the rotational characteristics of multi-layer strand wire ropes. In addition, we use CREO to establish a parameterized model for multi-layer strand wire ropes, and then set the material properties, contact parameters, and boundary conditions of the model in ABAQUS. Finally, the dynamic simulation of the multi-layer strand wire ropes model was completed. The results indicate that when the multi-layer strand wire rope is in a steady state, the twist angle has the greatest impact on the rotation angle, and under the same conditions, the rotation angle increases with the increase of the twist angle. The rotation angle at steady state is basically consistent with the theoretical calculation results, indicating that the theoretical influence of wire rope twist angle, wire diameter, material, and load on the rotation characteristics of multi-layer strand wire ropes is accurate.
Simulation of the Influence of Rotational Speed on the Crushing of Cement Agglomerates
Authors: Wang Binqiang , Shen Jianjun , Jia Feng , Sun Zehang
Published: June 2024

The uniform dispersion of cement agglomerates during the concrete mixing process affects the overall homogeneity of concrete and adversely affects its strength. To investigate the effect of mixing speed on the crushing of cement agglomerates, this article uses the discrete element software EDEM to simulate the process of crushing of cement agglomerates by collision with aggregates during the mixing process. Within the traditional mixing speed, three different mixing speeds are set to study the crushing ratio of cement agglomerates. The results show that, when other parameters are unchanged and the mixing speed is certain, the breaking of cement bonds shows a rapid increase in time and then a slow increase in time and finally tends to stabilize. To make the cement agglomerates uniformly dispersed, the mixing time should be maintained for more than 15 s at a speed of more than 60 rpm. When the speed is below 50 rpm, the mixing time should be extended and the mixing intensity should be increased.
Structural Stability Analysis of a High Power PEMFC Stack
Authors: Chen Ting , Pan Jie , Zhang Xiao , Guan Dong , Chen Zhen
Published: June 2024

An automobile fuel cell stack mounted horizontally will be subjected to a large impact in the direction parallel with the cells. This may cause interfacial slippage between cells, showing a downward bowing phenomenon, which may cause decay in the performance, and even stack leakage. Therefore, ensuring structural and mechanical integrity is very important in stack assembly design, especially for high power stacks with hundreds of unicells. In this paper, the authors presented numeric analysis for a 300 kW stack with 550 unicells, and analyzed the local vibration from the stack global modes based on finite element analysis (FEA), further evaluated the vibration responses, such as deformed shape and directions, then modified the stack structurally by applying the reinforcement bars, and finally confirmed the robustness of the reinforced stack. It is demonstrated that with proper design, a single stack with hundreds of unicells can be produced for vehicle applications.
Design and Dynamic-Static Characteristics Analysis of Electric Fuel Pump Boost Valve
Authors: Si Guolei , Li Binjie , Li Mengru , Zhou Caibo , Lu Liang , Zhang Zize
Published: June 2024

In response to the challenges of significant power loss and the difficulty in quickly blocking fuel reverse backflow in one-way valves used in electric fuel systems for aerospace engines, this paper proposes a pump boost valve with a main valve spool designed as a baffle structure and equipped with a backflow damping mechanism. The aim of this boost valve is to achieve flow distribution between the main and auxiliary fuel circuits during engine startup, thereby reducing ineffective power loss. The baffle spool design is implemented to block reverse fuel backflow, while the backflow damping mechanism is incorporated to regulate the dynamic and static characteristics of the boost valve. Based on the proposed design, the working principle is analysed, and a dynamic model is established using AMESim for the modelling and simulation study of the boost valve's dynamic and static characteristics. Comparative experiments are conducted between the newly designed boost valve and traditional boost valves, and the accuracy of the simulation model is validated through experimental verification. The experimental results confirm that the newly designed boost valve outperforms traditional valves in terms of reducing power loss and effectively blocking fuel reverse backflow. Additionally, through the analysis of parameters such as spring stiffness, spool diameter, and backflow damping hole, this study optimises the static and dynamic characteristics of the electric fuel pump. By optimizing these structural parameters, the performance of the electric fuel pump is improved, leading to enhanced stability and responsiveness.
Modelling and Finite Element Simulation of Ball-End Milling for Nickel-Based Superalloy Inconel 718
Authors: Zhang Yaoman , Zheng Jin
Published: June 2024

Comprehensive exploration of ball-end milling processes is presented in this paper, with a primary focus on the modelling of milling forces and the execution of finite element analysis during the machining of Inconel 718, a material known for its challenging machinability. A detailed milling force model, considering various parameters such as cutting speeds, feed rates, and depths of cut, has been developed, providing valuable insights into the optimization of machining parameters. Temperature and stress distributions within the tool during milling, particularly in the context of difficult-to-machine materials like Inconel 718, were investigated through finite element analysis. Critical temperature profiles at the tool tip, rake face, and flank face, which have an impact on tool wear and lifespan, were identified through the temperature field analysis. Notably, a maximum tool tip temperature of 682 °C was observed during the machining of Inconel 718. Challenges posed by difficult materials were unveiled through the stress field analysis, aiding in stress mitigation and enhancing the understanding of machining processes. In conclusion, a significant contribution is made by this paper to the understanding of ball-end milling processes.
Ultimate Strength Test and Numerical Simulation Analysis of Typical Cabin Made of a Novel Steel
Authors: Luan Chen , Lou Pengyu , Wang Hongfu , Wan Qi
Published: June 2024

A novel steel was proposed to apply to a ship, thereby enabling ships to safely complete their missions. But it is different in the ultimate bearing capacity between the novel material and traditional low-alloy high-carbon steels. There is little research on it. In this paper, the ultimate strength and the destruction mode of the typical cabin made of the novel steel under the hazardous condition are successfully obtained through a four-point bending test. Numerical simulation of the typical cabin at its limit state is verified by the test. Based on the numerical simulation method, theoretical initial deformation and ideal constitutive relation are introduced, which contributes to more conservative prediction for the ultimate strength of the ship made of the novel steel. This paper has guiding significance for subsequent tests and provides technical support for the structure design of the ship made of the novel steel.
Research of the Flow Field Characteristics of Flake Graphite in the Fan Shaped Nozzle of Premixed Water Jet
Authors: Dong Xing , Guo Chenhao , Chen Jifeng , Song Haorong
Published: June 2024

Graphite is an important strategic resource, in order to explore the flow performance of flake graphite in the flow field of the premixed water jet fan nozzle, numerical simulation of nozzle flow field was carried out by FLUENT software. According to the jet characteristics, the Euler model is selected to simulate the two-phase flow law of water and flake graphite, and standard k-ε turbulence model is selected as the turbulence model, the influence of different inlet pressure on the flow field distribution of flake graphite was analyzed. The results show that the axial velocity distribution of flake graphite flow field under different inlet pressures is similar, and the distribution cloud chart has significant plane symmetry, the jet plane diffuses outward at a certain angle. With the increase of target distance, the jet section changes from a flat structure to a symmetrical “groove” structure with high ends and low middle, the axial velocity of flake graphite flow field has secondary acceleration in the internal flow field and primary acceleration in the outward flow field, the maximum axial velocity appears near the nozzle outlet.
A Study on the Parameters Matching of Dynamics System Electric Bulldozer
Authors: Tian Congfeng , Tan Piqiang , Wang Wenpu , Hu Bin , Wang Zhaoliang , Song Jinbao , Xi Hanxiao
Published: June 2024

In this paper, the parameter matching of dynamics system electric bulldozer was proposed. Firstly, Structure and parameters of the electric bulldozer were introduced. Secondly, the speed and power of the motor were calculated. Finally, power battery parameter was calculated. The results show the peak torque of the drive motor is 800 N·m, the peak power is 100 kW, the maximum rotational speed is 3000 rpm, the rated rotational speed is 1200 rpm and discharge power of the power battery are 235kw.
Intelligent Construction Machinery SLAM with Stereo Vision and Inertia Fusion
Authors: Lin Tianliang , He Zhongyuan , Wu Jiangdong , Chen Qihuai , Fu Shengjie
Published: June 2024

Positioning technology is the foundation of intelligent construction machinery, the current mainstream positioning solution is simultaneous localization and mapping (SLAM) technology, which is mainly divided into lidar SLAM and visual SLAM. Due to the high cost of lidar, it is easy to degrade or even fail in scenes with a single environmental texture; while the cost of vision sensors is low and has a wealth of environmental texture information acquisition capabilities, which can effectively avoid degradation problems. In order to reduce the localization cost of intelligent construction machinery and improve the positioning accuracy, based on the VINS-Fusion stereo visual-inertial tightly coupled system framework, an improved Random Sampling Consensus (RANSAC) algorithm is used to reduce feature mismatch, and the Huber kernel function is used to IMU residuals and visual residuals are constrained to improve the effect of the SLAM system. Compared with the mainstream VINS-Fusion algorithm, the positioning root mean square error of this method on the EuRoC dataset is reduced by an average of 12.41%, which improves the positioning accuracy; simultaneously, the experimental results in the actual scene show that the motion trajectory of the algorithm, it is closer to the real trajectory than VINS-Fusion, which verifies the effectiveness of the method.
Design and Application of Hydraulic Inverted Pendulum
Authors: Ding Guyue , Bian Yongming , Yang Meng
Published: June 2024

This paper briefly describes the designing process of a hydraulic inverted pendulum including hardware and software design. First, the mechanical structure, including the components of the platform will be introduced. Second, the electrical system including controllers for receiving signals from sensors which measure the variables important for controlling inverted pendulum is about to be shown. Afterwards, the paper will present a mathematical model of the whole platform, then shows up an open loop simulation established by AMESim and Simulink in order to analysis its dynamic characteristic. By comparing the simulation result and reality, the rationality of mathematical model is finally verified.
Standard Components Query System Based on Logical Filtering and Semantic Retrieval
Authors: Huang Ziyan , Bian Yongming , Yang Meng
Published: June 2024

The establishment of a robust standard components database is essential in various industries to streamline product development and ensure quality. This paper presents a system for querying standard components data, leveraging the power of logical filtering and semantic retrieval. The structured approach of this system includes a well-defined database structure, logical filtering capabilities at different data levels, and advanced semantic retrieval techniques. The outputs of the system demonstrate its effectiveness in handling user queries, analysing unstructured data, and providing meaningful feedback based on logical filtering outcomes. This research contributes to the efficient utilization of standard components data through an innovative and powerful digital query system.
Energy Management Control Strategy of Series Hydraulic Hybrid Vehicle
Authors: Gong Jie , Zuo Jinyi
Published: June 2024

Aiming at a series hydraulic hybrid vehicle, the mathematical model and Matlab/Simulink simulation model of the vehicle are established, and the energy management strategy based on rules is put forward. The simulation results show that the control strategy not only realizes four working modes of hydraulic hybrid vehicle, but also improves its fuel economy by 11.9%. It is found that the volume of accumulator and the working pressure range of accumulator are two important parameters that affect the fuel economy of hydraulic hybrid vehicle. Under the condition of a certain accumulator volume, increasing the working pressure range of the accumulator can not only increase the energy storage of the accumulator, but also reduce the idling times of the engine and further improve the fuel economy of the vehicle.
Research on Leveling Strategy of Suspension System of Roadway Heavy-Load Transport Vehicle
Authors: Dai Jianjun , Zhang Hao , Li Wenlei , Guo Rui , Zhao Jingyi
Published: June 2024

As a transport device for underground equipment, the roadway heavy-load transport vehicle needs to ensure its safety and stability during loading and transportation. In order to reduce the overturning risk and improve the stability during transportation, the improved position error leveling method is proposed, and the effectiveness of the scheme is verified by simulation analysis and actual results.
Research on Wading Mobility of a Certain Type of Special Vehicle Based on MPS Method
Authors: Hao Yiyang , Zhou Yunbo , Zhang Ming
Published: June 2024

In order to study the wading mobility of a certain type of special vehicle, a high-precision dynamic model of the special vehicle is built. The vehicle dynamic model is verified by in-situ acceleration test and traction test. Through the dam-break experiment and wet road traction test, the feasibility and reliability of calculating the water impact pressure, buoyancy and solving the fluid–solid coupling problem based on the moving particle semi-implicit algorithm (MPS) are verified. Then, based on the MPS algorithm, a multi-body dynamics-fluid analysis simulation model is built to simulate and analyze the vehicle mobility under the static water wading condition and the water flow lateral impact condition. The relationship between the maximum speed of the vehicle at different water depths and gears under the static water wading condition the and the relationship between the lateral offset of the vehicle and the flow velocity and the deflection angle of the vehicle entering the water in the lateral impact condition are obtained.
Exploring oak processionary caterpillar induced lepidopterism (part 2): ex vivo bio-assays unmask the role of TRPV1
Authors: Seldeslachts Andrea , Undheim Eivind Andreas Baste , Vriens Joris , Tytgat Jan , Peigneur Steve
Published: June 2024

As human skin comes into contact with the tiny hairs or setae of the oak processionary caterpillar, Thaumetopoea processionea, a silent yet intense chemical confrontation occurs. The result is a mix of issues: skin rashes and an intense itching that typically lasts days and weeks after the contact. This discomfort poses a significant health threat not only to humans but also to animals. In Western Europe, the alarming increase in outbreaks extends beyond areas near infested trees due to the dispersion of the setae. Predictions indicate a sustained rise in outbreaks, fueled by global changes favoring the caterpillar’s survival and distribution. Currently, the absence of an efficient treatment persists due to significant gaps in our comprehension of the pathophysiology associated with this envenomation. Here, we explored the interaction between the venom extract derived from the setae of T. processionea and voltage- and ligand-gated ion channels and receptors. By conducting electrophysiological analyses, we discovered ex vivo evidence highlighting the significant role of TPTX1-Tp1, a peptide toxin from T. processionea, in modulating TRPV1. TPTX1-Tp1 is a secapin-like peptide and demonstrates a unique ability to modulate TRPV1 channels in the presence of capsaicin, leading to cell depolarization, itch and inflammatory responses. This discovery opens new avenues for developing a topical medication, suggesting the incorporation of a TRPV1 blocker as a potential solution for the local effects caused by T. processionea.
Insertion Algorithms for Gelfand $$S_n$$-Graphs
Authors: Marberg Eric , Zhang Yifeng
Published: June 2024

The two tableaux assigned by the Robinson–Schensted correspondence are equal if and only if the input permutation is an involution, so the RS algorithm restricts to a bijection between involutions in the symmetric group and standard tableaux. Beissinger found a concise way of formulating this restricted map, which involves adding an extra cell at the end of a row after a Schensted insertion process. We show that by changing this algorithm slightly to add cells at the end of columns rather than rows, one obtains a different bijection from involutions to standard tableaux. Both maps have an interesting connection to representation theory. Specifically, our insertion algorithms classify the molecules (and conjecturally the cells) in the pair of W-graphs associated with the unique equivalence class of perfect models for a generic symmetric group.
Analytical examination of shuttle-based storage and retrieval systems with multiple-capacity lifts
Authors: Eder Michael
Published: June 2024

The unbroken trend towards e-commerce and the ever-increasing demands on storage technology present the providers of storage systems with ever greater challenges. One way to meet these requirements is to significantly enhance warehouses’ handling systems. Multiple capacity lifts in tier-captive single-aisle shuttle-based storage and retrieval systems (SBS/RS) are a method to raise the throughput performance of such systems. Therefore, a straightforward calculation approach is presented based on a cycle time model combined with a time-continuous single open Markovian queue with limited capacity. A comparison of the invented approach to a discrete-event simulation (DES) is made to validate it. Finally, a numerical example of the influences of the different handling capacities and their usage in the design process of SBS/RS is depicted. The result is that with double the handling capacity, the throughput increases by about $$50\%$$

50
%

. Another result is sorting the stops within one handling cycle, which leads to a significantly higher throughput.
Characterization of biotinylated human ACE2 and SARS-CoV-2 Omicron BA.4/5 spike protein reference materials
Authors: Stocks Bradley B. , Thibeault Marie-Pier , L’Abbé Denis , Umer Muhammad , Liu Yali , Stuible Matthew , Durocher Yves , Melanson Jeremy E.
Published: June 2024

Accurate diagnostic and serology assays are required for the continued management of the COVID-19 pandemic yet spike protein mutations and intellectual property concerns with antigens and antibodies used in various test kits render comparability assessments difficult. As the use of common, well-characterized reagents can help address this lack of standardization, the National Research Council Canada has produced two protein reference materials (RMs) for use in SARS-CoV-2 serology assays: biotinylated human angiotensin-converting enzyme 2 RM, ACE2-1, and SARS-CoV-2 Omicron BA.4/5 spike protein RM, OMIC-1. Reference values were assigned through a combination of amino acid analysis via isotope dilution liquid chromatography tandem mass spectrometry following acid hydrolysis, and ultraviolet–visible (UV–Vis) spectrophotometry at 280 nm. Vial-to-vial homogeneity was established using UV–Vis measurements, and protein oligomeric status, monitored by size exclusion liquid chromatography (LC-SEC), was used to evaluate transportation, storage, and freeze–thaw stabilities. The molar protein concentration in ACE2-1 was 25.3 ± 1.7 µmol L−1 (k = 2, 95% CI) and consisted almost exclusively (98%) of monomeric ACE2, while OMIC-1 contained 5.4 ± 0.5 µmol L−1 (k = 2) spike protein in a mostly (82%) trimeric form. Glycoprotein molar mass determination by LC-SEC with multi-angle light scattering detection facilitated calculation of corresponding mass concentrations. To confirm protein functionality, the binding of OMIC-1 to immobilized ACE2-1 was investigated with surface plasmon resonance and the resulting dissociation constant, KD ~ 4.4 nM, was consistent with literature values.

Graphical Abstract
Metaplastic neuromodulation via transcranial direct current stimulation has no effect on corticospinal excitability and neuromuscular fatigue
Authors: Boda Madison R. , Otieno Lavender A. , Smith Ashleigh E. , Goldsworthy Mitchell R. , Sidhu Simranjit K.
Published: June 2024

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation tool with potential for managing neuromuscular fatigue, possibly due to alterations in corticospinal excitability. However, inconsistencies in intra- and inter- individual variability responsiveness to tDCS limit its clinical use. Emerging evidence suggests harnessing homeostatic metaplasticity induced via tDCS may reduce variability and boost its outcomes, yet little is known regarding its influence on neuromuscular fatigue in healthy adults. We explored whether cathodal tDCS (ctDCS) prior to exercise combined with anodal tDCS (atDCS) could augment corticospinal excitability and attenuate neuromuscular fatigue. 15 young healthy adults (6 males, 22 ± 4 years) participated in four pseudo-randomised neuromodulation sessions: sham stimulation prior and during exercise, sham stimulation prior and atDCS during exercise, ctDCS prior and atDCS during exercise, ctDCS prior and sham stimulation during exercise. The exercise constituted an intermittent maximal voluntary contraction (MVC) of the right first dorsal interosseous (FDI) for 10 min. Neuromuscular fatigue was quantified as an attenuation in MVC force, while motor evoked potential (MEP) amplitude provided an assessment of corticospinal excitability. MEP amplitude increased during the fatiguing exercise, whilst across time, force decreased. There were no differences in MEP amplitudes or force between neuromodulation sessions. These outcomes highlight the ambiguity of harnessing metaplasticity to ameliorate neuromuscular fatigue in young healthy individuals.
Importance of complex sponges as habitat and feeding substrata for coral reef fishes
Authors: Coppock Amy G. , Kingsford Michael J. , Jones Geoffrey P.
Published: June 2024

Coral reef fishes are usually assumed to be most strongly associated with reef-building corals. However, sponges can be a significant structural component of coral reef ecosystems and their framework can enhance the local abundance and biodiversity of fish assemblages. Little is known regarding the range of fish species using complex sponges as either shelter or feeding substrata. Here we use a combination of stationary video cameras and focal animal sampling to document fish species positively associated with complex sponges in Kimbe Bay, Papua New Guinea. Stationary cameras identified 45 fish species using the sponges for either shelter, feeding substrata or as sites for ambush predation. A guild of 10 individual fish species from five families (Blenniidae, Chaetodontidae, Gobiidae, Labridae and Pomacentridae) were observed to quantify sponge and other habitat use and compared with habitat availability to determine the level of sponge selectivity. One species, Pleurosicya elongata (the Slender Spongegoby), lived in obligate association with Ianthella basta (Elephant Ear sponge), and there was a positive relationship between sponge size and number of resident fish, however this was not significant for all life stages. Five other fish species appeared to preferentially select sponges as habitat (Amblyglyphidodon aureus, Chaetodon kleinii, Coradion chrysozonus, Escenius prooculis and Pomacentrus nigromanus), while for others, sponge use appeared incidental. When selectivity indices were calculated for specific sponge species it was apparent that some fishes exhibited preferences for particular sponge species or growth forms. These results suggest more fish species may be reliant on sponges than is widely appreciated.
Intramedullary headless screw fixation for fractures of the proximal phalanges of the hand: a three-year follow-up
Authors: Nietlispach Viviane , Besmens Inga S. , Medina Gontier Julie , Labèr Raffael , Frauenfelder Thomas , Calcagni Maurizio
Published: June 2024

Objective

The objective of this study was to evaluate the long-term outcomes of trans-articular intramedullary fixation using cannulated headless screws for proximal phalanx fractures in the hand.

Background

Various surgical techniques have been described for the fixation of proximal phalanx fractures, with Kirschner wires, plates, and screws being commonly used. The objective of this study was to evaluate the long-term outcomes of trans-articular intramedullary fixation using cannulated headless screws for proximal phalanx fractures in the hand. Methods Eight patients, with nine proximal phalanx fractures, treated with intramedullary screw fixation, were included for a follow-up visit three years post-surgery. Subjective and objective outcome measures were assessed using the Michigan Hand Questionnaire (MHQ), active range of motion (aROM), grip strength, conventional X-rays, and digital tomosynthesis images.

Methods

Eight patients, with nine proximal phalanx fractures, treated with intramedullary screw fixation, were included for a follow-up visit three years post-surgery. Subjective and objective outcome measures were assessed using the Michigan Hand Questionnaire (MHQ), active range of motion (aROM), grip strength, conventional X-rays, and digital tomosynthesis images.

Results

We observed a mean MHQ score of 83%, a total aROM of 216.4°, and a Jamar grip strength of 29.9 kg in the injured hand. Digital tomosynthesis revealed complete fracture consolidation in all cases. Joint arthrosis was detected in only one case, attributed to a misplaced screw.

Conclusions

Our findings indicate favorable long-term clinical outcomes, including range of motion, grip strength, patient satisfaction, and prevention of joint damage, with the use of intramedullary headless screw fixation.

Level of evidence: Level IV, Therapeutic
Whole pelvis vs. hemi pelvis elective nodal radiotherapy in patients with PSMA-positive nodal recurrence after radical prostatectomy - a retrospective multi-institutional propensity score analysis
Authors: Trapp Christian , Aebersold Daniel M. , Belka Claus , Casuscelli Jozefina , Emmett Louise , Eze Chukwuka , Fanti Stefano , Farolfi Andrea , Fendler Wolfgang , Grosu Anca-Ligia , Guckenberger Matthias , Hruby George , Kirste Simon , Koerber Stefan A. , Kroeze Stephanie , Peeken Jan C. , Rogowski Paul , Scharl Sophia , Shelan Mohamed , Spohn Simon K. B. , Strouthos Iosif , Unterrainer Lena , Vogel Marco , Wiegel Thomas , Zamboglou Constantinos , Schmidt-Hegemann Nina-Sophie
Published: June 2024

Purpose

Despite growing evidence for bilateral pelvic radiotherapy (whole pelvis RT, WPRT) there is almost no data on unilateral RT (hemi pelvis RT, HPRT) in patients with nodal recurrent prostate cancer after prostatectomy. Nevertheless, in clinical practice HPRT is sometimes used with the intention to reduce side effects compared to WPRT. Prostate-specific membrane antigen positron emission tomography / computed tomography (PSMA-PET/CT) is currently the best imaging modality in this clinical situation. This analysis compares PSMA-PET/CT based WPRT and HPRT.

Methods

A propensity score matching was performed in a multi-institutional retrospective dataset of 273 patients treated with pelvic RT due to nodal recurrence (214 WPRT, 59 HPRT). In total, 102 patients (51 in each group) were included in the final analysis. Biochemical recurrence-free survival (BRFS) defined as prostate specific antigen (PSA) < post-RT nadir + 0.2ng/ml, metastasis-free survival (MFS) and nodal recurrence-free survival (NRFS) were calculated using the Kaplan-Meier method and compared using the log rank test.

Results

Median follow-up was 29 months. After propensity matching, both groups were mostly well balanced. However, in the WPRT group there were still significantly more patients with additional local recurrences and biochemical persistence after prostatectomy. There were no significant differences between both groups in BRFS (p = .97), MFS (p = .43) and NRFS (p = .43). After two years, BRFS, MFS and NRFS were 61%, 86% and 88% in the WPRT group and 57%, 90% and 82% in the HPRT group, respectively. Application of a boost to lymph node metastases, a higher RT dose to the lymphatic pathways (> 50 Gy EQD2α/β=1.5 Gy) and concomitant androgen deprivation therapy (ADT) were significantly associated with longer BRFS in uni- and multivariate analysis.

Conclusions

Overall, this analysis presents the outcome of HPRT in nodal recurrent prostate cancer patients and shows that it can result in a similar oncologic outcome compared to WPRT. Nevertheless, patients in the WPRT may have been at a higher risk for progression due to some persistent imbalances between the groups. Therefore, further research should prospectively evaluate which subgroups of patients are suitable for HPRT and if HPRT leads to a clinically significant reduction in toxicity.
Safety and Effectiveness of Irreversible Electroporation in Lymph Node Metastases
Authors: Narayanan Govindarajan , Mahendra Ashwin M. , Gentile Nicole T. , Schiro Brian J. , Gandhi Ripal T. , Peña Constantino S. , Dijkstra Madelon
Published: June 2024

Purpose

Demonstrating the safety and efficacy of percutaneous irreversible electroporation (IRE) for the treatment of lymph node metastases.

Materials and Methods

An IRB-approved, single-center retrospective review was performed on patients with lymph node metastases gastrointestinal, and genitourinary primary cancers. Primary objective safety was evaluated by assessing complications graded according to the Clavien-Dindo Classification, and efficacy was determined by tumor response on follow-up imaging and local progression-free survival (LPFS). Secondary outcome measures were technical success (complete ablation with an adequate ablative margin > 5 mm), length of hospital stay and distant progression-free survival (DPFS).

Results

Nineteen patients underwent percutaneous IRE between June 2018 and February 2023 for lymph node metastases, close to critical structures, such as vasculature, bowel, or nerves. The technical success was achieved in all cases. Complications occurred in four patients (21.1%), including two self-limiting grade 1 hematomas, a grade 1 abdominal pain, and grade 2 nerve pain treated with medication. Seventeen patients were hospitalized overnight, one patient stayed two nights and another patient stayed fourteen nights. Median follow-up was 25.5 months. Median time to local progression was 24.1 months (95% CI: 0–52.8) with 1-, 2-, and 5-year LPFS of 57.9%, 57.9% and 20.7%, respectively. Median time to distant progression was 4.3 months (95% CI: 0.3–8.3) with 1-, 2-, and 5-year DPFS of 31.6%, 13.2% and 13.2%, respectively.

Conclusion

IRE is a safe and effective minimally-invasive treatment for lymph node metastases in locations, where temperature dependent ablation may be contraindicated. Care should be taken when employing IRE near nerves.

Graphical Abstract
Same same, but different: exploring the enigmatic role of the pituitary adenylate cyclase-activating polypeptide (PACAP) in invertebrate physiology
Authors: Pirger Zsolt , Urbán Péter , Gálik Bence , Kiss Bence , Tapodi Antal , Schmidt János , Tóth Gábor K. , Koene Joris M. , Kemenes György , Reglődi Dóra , Kiss Tibor , Fodor István
Published: June 2024

Evidence has been accumulating that elements of the vertebrate pituitary adenylate cyclase-activating polypeptide (PACAP) system are missing in non-chordate genomes, which is at odds with the partial sequence-, immunohistochemical-, and physiological data in the literature. Multilevel experiments were performed on the great pond snail (Lymnaea stagnalis) to explore the role of PACAP in invertebrates. Screening of neuronal transcriptome and genome data did not reveal homologs to the elements of vertebrate PACAP system. Despite this, immunohistochemical investigations with an anti-human PAC1 receptor antibody yielded a positive signal in the neuronal elements in the heart. Although Western blotting of proteins extracted from the nervous system found a relevant band for PACAP-38, immunoprecipitation and mass spectrometric analyses revealed no corresponding peptide fragments. Similarly to the effects reported in vertebrates, PACAP-38 significantly increased cAMP synthesis in the heart and had a positive ionotropic effect on heart preparations. Moreover, it significantly modulated the effects of serotonin and acetylcholine. Homologs to members of Cluster B receptors, which have shared common evolutionary origin with the vertebrate PACAP receptors, PTHRs, and GCGRs, were identified and shown not to be expressed in the heart, which does not support a potential role in the mediation of PACAP-induced effects. Our findings support the notion that the PACAP system emerged after the protostome-deuterostome divergence. Using antibodies against vertebrate proteins is again highlighted to have little/no value in invertebrate studies. The physiological effects of vertebrate PACAP peptides in protostomes, no matter how similar they are to those in vertebrates, should be considered non-specific.
An alternative approach of TUNEL assay to specifically characterize DNA fragmentation in cell model systems
Authors: Naselli Flores , Cardinale Paola Sofia , Volpes Sara , Martino Chiara , Cruciata Ilenia , Valenti Rossella , Luparello Claudio , Caradonna Fabio , Chiarelli Roberto
Published: June 2024

DNA damage is one of the most important effects induced by chemical agents. We report a comparative analysis of DNA fragmentation on three different cell lines using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, generally applied to detect apoptosis. Our approach combines cytogenetic techniques and investigation in detached cellular structures, recovered from the culture medium with the aim to compare the DNA fragmentation of three different cell line even beyond the cells adherent to substrate. Consequently, we detect any fragmentation points on single chromosomes, whole nuclei and other cellular structures. Cells were exposed to resveratrol (RSV) and doxorubicin (Doxo), in single and combined treatments. Control and treated astrocytes showed DNA damage in condensed nuclei and detached structures. Caco-2 cells showed fragmented DNA only after Doxo-treatment, while controls showed fragmented chromosomes, indicating DNA damage in replicating cells. MDA-MB-231 cells showed nuclear condensation and DNA fragmentation above all after RSV-treatment and related to detached structures. This model proved to perform a grading of genomic instability (GI). Astrocytes show a hybrid level of GI. Caco-2 cells showed fragmented metaphase chromosomes, proving that the DNA damage was transmitted to the daughter cells probably due to an absence of DNA repair mechanisms. Instead, MDA–MB-231 cells showed few or no fragmented metaphase, suggesting a probable activation of DNA repair mechanisms. By applying this alternative approach of TUNEL test, we obtained data that can more specifically characterize DNA fragmentation for a suitable application in various fields.
Development of autonomic heart rate modulations during childhood and adolescence
Authors: Helánová Kateřina , Šišáková Martina , Hnatkova Katerina , Novotný Tomáš , Andršová Irena , Malik Marek
Published: June 2024

Autonomic control of heart rate is well known in adult subjects, but limited data are available on the development of the heart rate control during childhood and adolescence. Continuous 12-lead electrocardiograms were recorded in 1045 healthy children and adolescents (550 females) aged 4 to 19 years during postural manoeuvres involving repeated 10-min supine, unsupported sitting, and unsupported standing positions. In each position, heart rate was measured, and heart rate variability indices were evaluated (SDNN, RMSSD, and high (HF) and low (LF) frequency components were obtained). Quasi-normalized HF frequency components were defined as qnHF = HF/(HF + LF). These measurements were, among others, related to age using linear regressions. In supine position, heart rate decreases per year of age were significant in both sexes but lower in females than in males. In standing position, these decreases per year of age were substantially lowered. RMSSD and qnHF indices were independent of age in supine position but significantly decreased with age in sitting and standing positions. Correspondingly, LF/HF proportions showed steep increases with age in sitting and standing positions but not in the supine position. The study suggests that baseline supine parasympathetic influence shows little developmental changes during childhood and adolescence but that in young children, sympathetic branch is less responsive to vagal influence. While vagal influences modulate cardiac periods in young and older children equally, they are less able to suppress the sympathetic influence in younger children.
Peri-implant phenotype, calprotectin and MMP-8 levels in cases diagnosed with peri-implant disease
Authors: Önder Yasemin Beliz , Alpaslan Nazli Zeynep
Published: June 2024

Objectives

The purpose of this prospective cohort study is to evaluate the effect of peri-implant phenotype (PPh) on the severity of peri-implant diseases and the results of non-surgical mechanical treatment (NSMT), along with calprotectin (CLP) and MMP-8(matrix metalloproteinase-8) levels.

Materials and methods

77 implants from 39 patients were included. The implants were categorized Group-1(peri-implant mucositis), Group-2(peri-implantitis).Baseline (0. Month-PrT) clinical parameters (PD, GI, PI, BOP, CAL) and radiographic bone loss were documented, and peri-implant crevicular fluid (PICF) samples were collected. Various intruments and methodologies were employed to assess PPh components (mucosa thickness, supracrestal tissue height, keratinized mucosa) and peri-implant attached mucosa (AM). NSMT was applied to diseased implant sites. All clinical parameters were reassessed again by taking PICF samples at the 6th month-after treatment (PT). In PICF samples obtained from both groups, MMP-8 and CLP levels were evaluated using the ELISA test.

Results

PrT-PD,PrT-GI,PrT-CAL and PrT-BOP percentage values in Group-2 were significantly higher than Group-1.PrT-PD,PrTPI scores are significantly higher in thin biotype implants. All components of the PPh and AM were significantly lower in thin biotype. Intra-group time-dependent changes of MMP-8 and CLP were significant in both groups (p < 0.05). When the relationship between thin and thick biotype and biochemical parameters was evaluated, the change in PrT-PT didn’t show a significant difference (p > 0.05).

Conclusions

PPh plays a role in influencing the severity of peri-implant diseases. However, the impact of phenotype on NSMT outcomes was similar in both groups.

Clinical relevance

The PPh should be considered when planning implant surgery.
The extracellular matrix protein EMILIN-1 impacts on the microenvironment by hampering gastric cancer development and progression
Authors: Capuano Alessandra , Vescovo Maddalena , Canesi Simone , Pivetta Eliana , Doliana Roberto , Nadin Maria Grazia , Yamamoto Masami , Tsukamoto Tetsuya , Nomura Sachiyo , Pilozzi Emanuela , Palumbo Antonio , Canzonieri Vincenzo , Cannizzaro Renato , Scanziani Eugenio , Baldassarre Gustavo , Mongiat Maurizio , Spessotto Paola
Published: June 2024

Background

The contribution of the tumor microenvironment and extracellular matrix to the aggressive biology of Gastric Cancer (GC) has been recently characterized; however, the role of EMILIN-1 in this context is unknown. EMILIN-1 is an essential structural element for the maintenance of lymphatic vessel (LV) integrity and displays anti-proliferative properties as demonstrated in skin and colon cancer. Given the key role of LVs in GC progression, the aim of this study was to investigate the role of EMILIN-1 in GC mouse models.

Methods

We used the syngeneic YTN16 cells which were injected subcutaneously and intraperitoneally in genetically modified EMILIN-1 mice. In alternative, carcinogenesis was induced using N-Methyl-N-nitrosourea (MNU). Mouse-derived samples and human biopsies were analyzed by IHC and IF to the possible correlation between EMILIN-1 expression and LV pattern.

Results

Transgenic mice developed tumors earlier compared to WT animals. 20 days post-injection tumors developed in EMILIN-1 mutant mice were larger and displayed a significant increase of lymphangiogenesis. Treatment of transgenic mice with MNU associated with an increased number of tumors, exacerbated aggressive lesions and higher levels of LV abnormalities. A significant correlation between the levels of EMILIN-1 and podoplanin was detected also in human samples, confirming the results obtained with the pre-clinical models.

Conclusions

This study demonstrates for the first time that loss of EMILIN-1 in GC leads to lymphatic dysfunction and proliferative advantages that sustain tumorigenesis, and assess the use of our animal model as a valuable tool to verify the fate of GC upon loss of EMILIN-1.
Predicting EGFR Status After Radical Nephrectomy or Partial Nephrectomy for Renal Cell Carcinoma on CT Using a Self-attention-based Model: Variable Vision Transformer (vViT)
Authors: Usuzaki Takuma , Inamori Ryusei , Ishikuro Mami , Obara Taku , Takaya Eichi , Homma Noriyasu , Takase Kei
Published: June 2024

Objective

To assess the effectiveness of the vViT model for predicting postoperative renal function decline by leveraging clinical data, medical images, and image-derived features; and to identify the most dominant factor influencing this prediction.

Materials and Methods

We developed two models, eGFR10 and eGFR20, to identify patients with a postoperative reduction in eGFR of more than 10 and more than 20, respectively, among renal cell carcinoma patients. The eGFR10 model was trained on 75 patients and tested on 27, while the eGFR20 model was trained on 77 patients and tested on 24. The vViT model inputs included class token, patient characteristics (age, sex, BMI), comorbidities (peripheral vascular disease, diabetes, liver disease), habits (smoking, alcohol), surgical details (ischemia time, blood loss, type and procedure of surgery, approach, operative time), radiomics, and tumor and kidney imaging. We used permutation feature importance to evaluate each sector's contribution. The performance of vViT was compared with CNN models, including VGG16, ResNet50, and DenseNet121, using McNemar and DeLong tests.

Results

The eGFR10 model achieved an accuracy of 0.741 and an AUC-ROC of 0.692, while the eGFR20 model attained an accuracy of 0.792 and an AUC-ROC of 0.812. The surgical and radiomics sectors were the most influential in both models. The vViT had higher accuracy and AUC-ROC than VGG16 and ResNet50, and higher AUC-ROC than DenseNet121 (p < 0.05). Specifically, the vViT did not have a statistically different AUC-ROC compared to VGG16 (p = 1.0) and ResNet50 (p = 0.7) but had a statistically different AUC-ROC compared to DenseNet121 (p = 0.87) for the eGFR10 model. For the eGFR20 model, the vViT did not have a statistically different AUC-ROC compared to VGG16 (p = 0.72), ResNet50 (p = 0.88), and DenseNet121 (p = 0.64).

Conclusion

The vViT model, a transformer-based approach for multimodal data, shows promise for preoperative CT-based prediction of eGFR status in patients with renal cell carcinoma.