bluuebunny/crossref_metadata_2025 huggingface dataset:
The study on the influence of different damage introduction methods on the damage characteristics of aircraft composites
Authors: Zhang Yao
Published: December 2023

Composite materials have advantages incomparable to traditional metal materials. However, they are more sensitive to impact damage and their mechanical properties decrease significantly after impact damage. Therefore, it is of great significance to study the energy absorption, mechanical response and damage mechanism of materials in different ways. To study the influence of different punch diameter sizes on the material damage characteristics, three kinds of punch diameters of 12.7 mm, 16 mm and 25.4 mm are selected to carry out the quasistatic indentation test and drop hammer impact damage test on the test pieces respectively. The material damage caused by different punch sizes under two damage introduction methods is analyzed. Damage introduction was carried out on the test piece with the same layering through two methods: quasi-static indentation and drop hammer impact. The damage depth, damage area and residual strength were compared after damage introduction. The difference between quasistatic indentation and drop hammer impact damage introduction was verified by comparing the damage characteristics to each other. The results show that with the increase of punch diameter size, the damage area decreases and the residual strength of the material increases. In addition, the test results of different punch diameter sizes under the two damage introduction methods have the same change trend, which proves that the impact of punch size on the material damage characteristics has no obvious relationship with the damage introduction method. Quasi-static indentation and drop hammer impact damage have no significant difference in the residual strength of materials after damage, which verifies the equivalence of static indentation and damage introduction.
Flexible Adaptive Integrated Compensation Strategy for Voltage Sag
Authors: Li Baojuan , Shang Fangbin , Wang Renzheng , Wu Xiaojie , Fan Di
Published: December 2023

A dynamic voltage restorer (DVR) is often used for voltage compensation to reduce or eliminate the harm of voltage sag. The existing combined compensation strategy does not consider the specific process of voltage sag, so it cannot adapt to the change according to the drop depth and eliminate the phase abrupt change. In this paper, a flexible, adaptive combination compensation strategy is proposed, which adopts the appropriate compensation strategy according to the actual voltage change process, sets the transition period to avoid phase jump, and adopts the full voltage compensation strategy to fully recover the phase at the end of the voltage dip, to realize the adaptive, flexible compensation of voltage. The simulation results show that the compensation strategy varies with the voltage drop depth. Both the intermediate phase fluctuation and the energy consumption are smaller. The final compensation is complete.
Control Strategy of Three-level Active Neutral Point Clamped Grid Connected Inverters in Unbalanced Power Grid
Authors: Chen Yuwei , Guo Kunli , Bai Yang
Published: December 2023

Traditional phase-locked loops in three-level active neutral point-clamped inverter grid-connected systems for photovoltaic power generation exhibit a deficiency in the decoupling of positive and negative sequences under unbalanced power grid conditions. To address this issue, this study proposes the implementation of the fourth-order generalized integrator into the phase-locked loop to facilitate positive and negative sequence decoupling. Initially, a 3L-ANPC inverter grid connection system is established. However, under unbalanced grid voltage conditions, the PLL effect of the Decoupled Double Synchronous Reference Frame Phase-Locked Loop is found to be suboptimal, leading to considerable fluctuations and distortions in the output frequency signal. To address these complications, we propose an optimized phase-locked loop structure. In this improved design, the PLL first utilizes the FOGI to filter out multiple harmonics in the grid voltage prior to decoupling the positive and negative sequence voltage. This process effectively mitigates the effect on the PLL, thereby enabling rapid and precise tracking of the grid voltage. Simulation analysis is conducted by using Matlab/Simulink to substantiate the effectiveness of the proposed PLL, demonstrating its ability to reliably lock onto the frequency and phase of the fundamental voltage under conditions of unbalanced power grid voltage.
Estimation of Battery State of Charge Based on Electrochemical Impedance Spectroscopy and Machine Learning
Authors: Guo Dongliang , Guo Pengyu , Sun Lei
Published: December 2023

With the increasing application of lithium-ion batteries in energy storage (ES) and electric vehicles (EV), the operation state and the safety early warning are particularly important. Due to the complexity of lithium-ion batteries, predicting the state of charge (SOC) of batteries is still a great challenge. In this paper, an electrochemical impedance spectroscopy (EIS) based on the SOC estimation method was proposed. The EIS of different SOC under 25℃ was measured, and the variation characteristics of EIS were summarized from the aspects of amplitude and phase by using the full band information. Finally, the linear system and BP neural network model were constructed by selecting the characteristic parameters at a specific frequency. The results demonstrate that the prediction effect of the BP neural network is better, and the error is found to be less than 3%.
A Sympathetic Inrush Identification Method Based on the Time-Frequency Energy
Authors: Peng Fang , Gao Houlei
Published: December 2023

Sympathetic inrush is a phenomenon caused by the energization of the neighboring unloaded transformer. It may cause current differential protection to operate in the wrong way. Due to the lack of a special and continuous identification method, this paper studies the inherent feature of the two transformers during sympathetic inrush. Then a substation-area current signal based on the feature is constructed and its characteristics are analyzed. The time-frequency energy of the current signal is extracted based on the synchrosqueezed wavelet transform (SWT) since the SWT can process the transient signals accurately. The extracted energy is taken as the basis of the identification criterion. The simulation results conducted by PSCAD/EMTDC software prove the accuracy and effectiveness of the proposed method.
Optimized Transfer Learning Based Short-term Electrical Load Interval Prediction
Authors: Bai Qinyi , Huang Dongbin , Xiao Ling
Published: December 2023

Electrical load forecasting is an essential foundation for power reliable and economical operation of the power grid. Most forecasting models regard the prediction results as deterministic variables, which ignores the randomness and volatility of the power load. At the same time, insufficient historical load data often lead to undertrained models, which affects the accuracy of capturing uncertain information. Therefore, we proposed an optimized transfer learning-based method for short-term load-interval prediction. A deep learning quantile regression model would be constructed by source domain data in the method, and the weights of the source model would be optimized to avoid negative transfer. Then, the target model is constructed by parameter transfer based on key layers and is tuned with hyperparameters by target domain data. From the experimental discussion, it is known that the model with an optimized transfer learning strategy can accurately quantify the fluctuation range of future power load.
Research on Networking of 10 kV Substation Management Information Area
Authors: Xiao Suchao , Wang Nan , Wang Shixin , Shen Xiangming
Published: December 2023

At present, the substation network management information area, as an essential part of the substation network communication, is an important transmission channel to realize the intelligent auxiliary control of the substation network. Establishing a stable and reliable substation management information area network has become an essential part of upgrading the substation network. Firstly, this paper designs a Gigabit-Capable PON, and an industrial Ethernet networking scheme, based on certain city data. Secondly, based on the availability of single-device operation, a calculation model algorithm for reliability analysis is innovatively proposed to realize the comparison of networking solutions. Thirdly, regarding the economy, the concept of unit incremental investment reliability index is applied to two groups of networking solutions comparison for the first time. Finally, a networking scheme and suggestions for the substation network management information area are proposed.
Topological Singularity Pair in Nonreciprocal Non-Hermitian Lossy-dielectric Gyromagnetic Metasurface
Authors: Jiang Yimin , Wong Wai Chun , Fung Kin Hung , Yu Siu Fung
Published: December 2023

The transmission properties of a nonreciprocal non-Hermitian metasurface composed of lossy dielectric and gyromagnetic materials are studied with closed-form analytical solutions. It is found that a pair of opposite topological singularities of isolation ratio exist in a two-dimensional (2D) parameter space, and their evolution with parameter adjustment is preliminarily studied. These results provide clues for the design of optical devices. Further study of the mechanism of this singular behavior may reveal the complex systematic effect of non-Hermiticity and non-reciprocity on optical performance.
A WSN clustering routing method based on an improved WOA-optimized K-means clustering algorithm
Authors: Jiang Zihao , Chen Renwen , Liu Hao , Zhang Junyi , Li Shanan
Published: December 2023

To address the problem of transmission energy consumption and premature node death in wireless sensor networks (WSN), a novel routing strategy by IWOA that optimizes the K-means (KM) is proposed. WOA is improved by using it to optimize the KM algorithm, and more evenly distributed and suitable cluster centers are selected as the initial cluster heads (CH). In the CH election process, a CH election function is established, and the optimal CH under the influence of multiple factors is obtained. The simulation results have verified the feasibility of the proposed scheme in this paper.
Collaborative Scheduling Algorithm for Dependent Tasks based on Multi-Agent RL in VEC Environment
Authors: Xu Pengfei , Ding Xu , Zheng Xiang , Zhang Bixun , Lyu Qingzhou , Liang Tao , Shi Lei
Published: December 2023

To address the problem of limited computing power of vehicles, Vehicle Edge Computing (VEC) allows vehicles to schedule tasks to edge nodes with sufficient resources. In this paper, we propose a multi-agent reinforcement learning (MARL) approach to solve the multi-task scheduling problem in a dynamic VEC environment. First, we model the cooperative scheduling problem of dependent tasks in the VEC environment, considering the task priority and edge node load balancing in the task scheduling process. We define the optimization objective as minimizing the task processing delay and find it is an NP-hard problem. Then, we design a distributed algorithm SCMA based on MARL. The algorithm enables vehicles to find the optimal scheduling strategy by cooperating and sharing resources with each other. Finally, we use SUMO to simulate the road network topology and generate vehicle traffic trajectories. We construct heterogeneous vehicular applications for simulation experiments using the DAG generator. Compared with existing algorithms, the simulation results validate the superiority of the SCMA algorithm.
A Fast Gap Detection Algorithm Based on Machine Vision
Authors: Li Pengxin , Gao Quanqin , Chen Yuepeng , Sun Haiyang , Cai Qingyu , Tang Xiaoan
Published: December 2023

In order to be able to quickly locate the position of the gap of an industrial device in the industrial inspection process, a fast gap detection algorithm based on machine vision is proposed by using the feature of a high gray level difference between the image gap and the background in machine vision. First, nonlinear equalization preprocessing is adopted, and then multiple one-dimensional functions are composed based on the sum of the gray values of the horizontal axis as well as the differentiation, and then the proximity position averaging operation is done after obtaining the positional information through the extreme value and the most value operation. The algorithm transforms the two-dimensional image into a combination of multiple one-dimensional functions with related features, and finally accurate position information is obtained by analysing and fusing the one-dimensional functions. Multiple discriminative bases are used for the same data source to ensure the accuracy of the results. Experiments show that the method proposed is faster and less error-prone, has higher accuracy and detection efficiency, and meets the needs of industrial real-time detection, compared with the traditional Hough transform algorithm and the LSD detection algorithm.
Research on 5G Network Slicing Algorithm Based on the Smart Grid
Authors: Teng Wanyi , Yang Xu
Published: December 2023

To address the problem of network-slicing resource allocation in the smart grid, this paper puts forward a hierarchical network-slicing resource scheduling strategy for the smart grid based on priority and network utility, which is a study of the 5G net slice resource allocation (the max algorithm of utility). It is divided into two layers, which are the user layer and the slice allocation layer. By adopting different resource allocation methods to better meet the service and the experience quality of power users in different slices, the simulation results playing the strategy are better than the other number of resource allocation schemes.
Sputtered vanadium carbon nitride (VCN) thin films: a potential electrode for supercapacitors
Authors: Prasath G Vijaya , Vivekanandan J , Selvamurugan M , Usha K S , Sakthivel P , Babu G Anandha , Ravi G
Published: December 2023

The preparation of efficient thin film-based electrode materials is a vital prerequisite for practical energy storage devices. Herein, we have prepared unique vanadium carbon nitride (VCN) thin films on FTO substrates by pulsed DC magnetron sputtering technique for competent supercapacitor electrodes. XRD analysis confirmed the crystalline nature of VCN thin films. SEM and AFM revealed a smooth morphology with an average grain size of 30 nm. Raman spectra showed two broad peaks around 1346 and 1589 cm−1, belonging to the D-band and G-band of VCN. The surface electronic states of VCN were investigated by XPS analysis, which confirmed the formation of pure VCN films without any impurities. The electrochemical performance of the thin film electrode was evaluated using cyclic voltammetry (CV), Galvanostatic charge–discharge (GCD), and Electrochemical impedance analysis (EIS). The electrochemical results showed the VCN thin films exhibited super capacitive behaviours. The maximum specific capacitance (Cs) value of 78.2 F g−1 was obtained from GCD studies. A variation in charge transfer resistance is detected from the EIS study, which arises due to the partial oxidation of the active nitride component. The VCN electrode showed good cycling stability, retaining 87% of its capacitance at a current density of 5 A g−1 even after 2000 cycles. The sputtered VCN films have been demonstrated as potential thin film electrodes for electrochemical supercapacitors for practical energy storage devices.
Observationally constrained mass balance box model analysis of aerosol mitigation potential using fan powered filters
Authors: Wang Shuo , Cohen Jason Blake , Wang Xinying , Chen Weina , Deng Weizhi , Tiwari Pravash , Yang Yuanjian , Lolli Simone
Published: December 2023

Indoor air pollution contributes significantly as a world-wide environmental issue, impacting health and livelihood. To quantify benefits of filtration on indoor air quality, it is essential to understand the relationships between the various factors impacting the concentrations of indoor air pollutants. This work uses a mass-conserving 2-box model, high-frequency observations of aerosol number concentration, and a home-made, low-cost, 3-layer non-woven fabric filter, powered by a standard ventilation fan to quantify the effectiveness aerosol reduction in multiple indoor environments. The data shows that aerosol loading is effectively reduced under both steady-state and extreme event conditions, although there are significant and important differences between simultaneous observations both indoor and outside. To obtain a proper accounting, the following must be considered: the usage or not of the fan filter, whether windows are opened or closed, the state of outdoor air is pollution, and the strength and duration of indoor emissions. The experiments are applied in residential indoor environments in four cities in eastern (Xuzhou), central (Zhoukou), and southern (Zhuhai and Shunde) China. Photographic evidence of the altered fan filter state under both conditions show that while usually dark/black aerosols dominate, there are conditions when yellow aerosols also dominate. The observations are based on multiple, independent, continuous low-cost sensors which have been calibrated against a GRIMM-180 over the number concentration range from 0.3 to 1.0 microns, and yield a removal rate due to the fan-filter of 46%, 80%, 81%, and 36% respectively across the four cities. A corresponding rate to return from an extreme event to steady-state, is computed outdoors and indoors respectively from: 14.−44. minutes, 6.6–21. minutes, 16.−33. minutes, and 24.−58. minutes. The most important factors contributing to the removal efficiency and decay gradient are observed as keeping windows closed and reducing leakiness, the apartment/classroom size, and the outdoor air pollution loading.
Computational phase transition signature in Gibbs sampling
Authors: Philathong Hariphan , Akshay Vishwanathan , Zacharov Igor , Biamonte Jacob
Published: December 2023

Gibbs sampling is fundamental to a wide range of computer algorithms. Such algorithms are set to be replaced by physics based processors—be it quantum or stochastic annealing devices—which embed problem instances and evolve a physical system into a low-energy ensemble to recover a probability distribution. At a critical constraint to variable ratio, satisfiability (SAT) problem instances exhibit a SAT-UNSAT transition (frustrated to frustration free). Algorithms require increasing computational resources from this critical point. This is a so called, algorithmic or computational phase transition and has extensively been studied. In this paper we consider the complexity in sampling and recovering ground states from resultant distributions of a physics based processor. In particular, we first consider the ideal Gibbs distributions at some fixed inverse temperature and observe that the success probability in sampling and recovering ground states decrease for instances starting at the critical density. Furthermore, simulating the Gibbs distribution, we employ Ising spin dynamics, which play a crucial role in understanding of non-equilibrium statistical physics, to find their steady states of 2-SAT Hamiltonians. We observe that beyond the critical density, the probability of sampling ground states decreases. Our results apply to several contemporary devices and provide a means to experimentally probe a signature of the computational phase transition.
Bark wings are related to the primary vascular system: the case of Piptadenia gonoacantha (Leguminosae)
Authors: Teixeira Felippe A , Gerolamo Caian S , Junior Amilcar W S , Pace Marcelo R
Published: December 2023

Bark wings are projections commonly interpreted as plant protective structures against herbivory. Their location in stems has been typically thought to be random, something that here we dispute, using Piptadenia gonoacantha as a case study. We collected stem samples from several specimens in different developmental stages from natural populations in the Brazilian Atlantic rainforest. These stems were studied in detail under light microscopy to determine the formation of bark wings and their possible correlation with other anatomical features. Stems of P. gonoacantha are deeply lobed during primary growth, with each lobe containing a large vascular bundle, alternating with smaller vascular bundles in the interlobes. On top of these lobes, prickles develop, being composed of epidermal tissue and the cortex beneath. Some of the eight lobes merge and a phellogen is installed on top of them, which starts to produce a large sheath of phellem, which will become the conspicuous bark wings of Piptadenia. The phellogen switches on and off, leaving marks resembling growth rings. The bark wings in Piptadenia have very specific positioning, always in the front of five to eight major vascular bundles, indicating that bark wings appear always in very precise locations.
Perioperative outcomes of bi-pigtail catheter drainage strategy versus conventional chest tube after uniportal video-assisted thoracic lung surgery
Authors: Song Liwei , Chen Xingshi , Zhu Li , Qian Gang , Xu Yanhui , Song Zuodong , Li Jiantao , Chen Tianxiang , Huang Jia , Luo Qingquan , Cheng Xinghua , Yang Yunhai
Published: December 2023

OBJECTIVES

Chest tube (CT) drainage is a main cause of postoperative pain in lung surgery. Here, we introduced a novel drainage strategy with bi-pigtail catheters (PCs) and conducted a randomized controlled trial to compare with conventional CT drainage after uniportal video-assisted thoracic surgery lung surgery.

METHODS

A single-centre, prospective, open-labelled, randomized controlled trial (ChiCTR2000035337) was conducted with a preplanned sample size of 396. The primary outcome was the numerical pain rating scale (NPRS) on the first postoperative day. Secondary outcomes included other indicators of postoperative pain, drainage volume, duration of drainage, postoperative hospital stay, incidence of postoperative complications, CT reinsertion and medical costs.

RESULTS

A total number of 396 patients were randomized between August 2020 and January 2021, 387 of whom were included in the final analysis. The baseline and clinical characteristics of the patients were well balanced between 2 groups. The NPRS on the first postoperative day was significantly lower in the PC group than in the CT group (2.40 ± 1.27 vs 3.02 ± 1.39, p < 0.001), as well as the second/third-day NPRS, the incidence of sudden severe pain (9/192, 4.7% vs 34/195, 17.4%, P < 0.001) and pain requiring intervention (19/192, 9.9% vs 46/195, 23.6%, P < 0.001). In addition, the medical cost in the PC group was lower (US$7809 ± 1646 vs US$8205 ± 1815, P = 0.025). Univariable and multivariable analyses revealed that the drainage strategy was the only factor influencing the incidence of pain requiring intervention.

CONCLUSIONS

The drainage strategy with bi-PCs in patients undergoing uniportal video-assisted thoracic surgery lung surgery alleviates postoperative pain with adequate safety and efficacy.
Direct Seeding for Conifer Regeneration in the Pacific Northwest: A Past, Present, and Future of Operational Practices
Authors: Downer Rebecca , Manteuffel-Ross Tiffani , Tymon Lydia , Aghai Matthew
Published: December 2023

United States Pacific Northwest (PNW) forests are important ecological, cultural, and recreational landscapes. Direct seeding to aid forest regeneration in the PNW region was developed to reduce reforestation costs and timelines. These practices were largely discontinued in the 1970s due to poor establishment resulting from issues of seed predation, a lack of targeting favorable site conditions, seed distribution issues, and improvements to nursery seedling production. A recent renewed interest in direct seeding research has resulted from the growing geographic extent of postdisturbance areas requiring reforestation. This interest is also supported by the increasing recognition of the logistical impossibility of satisfying reforestation demand via planted seedlings. This historical review highlights the timeline of direct seeding research and practice in the PNW. It describes the main obstacles to its widespread use and opportunities for improvement. These opportunities include upscaling seed collection efforts, increasing distribution precision of seeding methods, upgrading seed quality evaluations, and mitigating seed predation and desiccation.

Study Implications: The availability of seedlings is increasingly limited due to the rising demand for reforestation as a result of more frequent and severe wildfires. Further research into direct seeding as an artificial regeneration strategy for trees is necessary to operationally increase reforestation abilities and thus supplement natural regeneration and seedling planting. This study summarizes findings from prior direct seeding studies in the Pacific Northwest region and identifies (1) improving seed collection efforts, (2) refining seed quality assessments, (3) standardizing seed dispersal methods, and (4) improving seedling establishment by targeting favorable site conditions and predation mitigation as key future research priorities.
Detection and Quantification of Extraterrestrial Platinum Group Element Alloy Micronuggets from Archean Impactite Deposits by Low-Voltage Scanning Electron Microscopy/Energy-Dispersive X-ray Spectrometry
Authors: Salge Tobias , Mohr-Westheide Tanja
Published: December 2023

Rare, heterogeneously composed platinum group element alloy micronuggets (PGNs) occur in primitive meteorites, micrometeorites, and terrestrial impactite deposits. To gain insight into the nature of these phases, we developed a workflow for the characterization of PGNs using modern scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry at a low accelerating voltage of 6 kV. Automated feature analysis—a combination of morphological image analysis and elemental analysis with stage control—allowed us to detect PGNs down to 200 nm over a relatively large analysis area of 53 mm2 with a conventional silicon drift detector (SDD). Hyperspectral imaging with a high-sensitivity, annular SDD can be performed at low beam current (∼100 pA) which improves the SEM image resolution and minimizes hydrocarbon contamination. The severe overlapping peaks of the platinum group element L and M line families at 2–3 keV and the Fe and Ni L line families at <1 keV can be resolved by peak deconvolution. Quantitative elemental analysis can be performed at a spatial resolution of <80 nm; however, the results are affected by background subtraction errors for the Fe L line family. Furthermore, the inaccuracy of the matrix correction coefficients may influence standards-based quantification with pure element reference samples.
False-Positive Human Immunodeficiency Virus Nucleic Acid Amplification Test After Chimeric Antigen Receptor T-Cell Therapy With Ciltacabtagene Autoleucel
Authors: Keri Vishakh C , Topulli Mary Vito , Deol Abhinav , Uberti Joseph , Salimnia Hossein , Chandrasekar Pranatharthi H
Published: December 2023

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a novel therapeutic option for hematologic malignancies. Human immunodeficiency virus (HIV) nucleic acid amplification tests (NAATs) amplifying 5′ long terminal repeat and gag genes cross-react with lentiviral vector-based CAR T-cell products. Cross-reactivity between CAR T-cell products and HIV NAATs may lead to false-positive test results.
The Role of Soil Abundance of TxtAB in Potato Common Scab Disease Severity
Authors: Shelley Brett A. , Pandey Binod , Sarwar Arslan , Douches David , Collins Paul , Qu Xinshun , Pasche Julie , Clarke Christopher R.
Published: December 2023

Common scab is an economically costly soilborne disease of potato endemic in many potato-growing regions. The disease is caused by species of Streptomyces bacteria that produce the phytotoxin thaxtomin A. The primary disease management tool available to growers is planting resistant cultivars, but no cultivar is fully resistant to common scab, and partially resistant cultivars are often not the preferred choice of growers because of agronomic or market considerations. Therefore, growers would benefit from knowledge of the presence and severity of common scab infestations in field soils to make informed planting decisions. We implemented a quantitative PCR diagnostic assay to enable field detection and quantification of all strains of Streptomyces that cause common scab in the United States through amplification of thaxtomin A biosynthetic genes. Greenhouse trials confirmed that pathogen abundance was highly correlated with disease severity for five distinct phytopathogenic Streptomyces species, although the degree of disease severity was dependent on the pathogen species. Correlations between the abundance of the thaxtomin biosynthetic genes from field soil with disease on tubers at field sites across four U.S. states and across 2 years were not as strong as correlations observed in greenhouse assays. We also developed an effective droplet digital PCR diagnostic assay that also has potential for field quantification of thaxtomin biosynthetic genes. Further improvement of the PCR assays and added modeling of other environmental factors that impact disease outcome, such as soil composition, can aid growers in making informed planting decisions.
Multicenter, Randomized, Placebo-controlled Crossover Trial Evaluating Topical Lidocaine for Mechanical Cervical Pain
Authors: Cohen Steven P. , Larkin Thomas M. , Weitzner Aidan S. , Dolomisiewicz Edward , Wang Eric J. , Hsu Annie , Anderson-White Mirinda , Smith Marin S. , Zhao Zirong
Published: December 2023

Background

There are few efficacious treatments for mechanical neck pain, with controlled trials suggesting efficacy for muscle relaxants and topical nonsteroidal anti-inflammatory drugs. Although studies evaluating topical lidocaine for back pain have been disappointing, the more superficial location of the cervical musculature suggests a possible role for topical local anesthetics.

Methods

This study was a randomized, double-blind, placebo-controlled crossover trial performed at four U.S. military, Veterans Administration, academic, and private practice sites, in which 76 patients were randomized to receive either placebo followed by lidocaine patch for 4-week intervals (group 1) or a lidocaine-then-placebo patch sequence. The primary outcome measure was mean reduction in average neck pain, with a positive categorical outcome designated as a reduction of at least 2 points in average neck pain coupled with at least a 5-point score of 7 points on the Patient Global Impression of Change scale at the 4-week endpoint.

Results

For the primary outcome, the median reduction in average neck pain score was −1.0 (interquartile range, −2.0, 0.0) for the lidocaine phase versus −0.5 (interquartile range, −2.0, 0.0) for placebo treatment (P = 0.17). During lidocaine treatment, 27.7% of patients experienced a positive outcome versus 14.9% during the placebo phase (P = 0.073). There were no significant differences between treatments for secondary outcomes, although a carryover effect on pain pressure threshold was observed for the lidocaine phase (P = 0.015). A total of 27.5% of patients in the lidocaine group and 20.5% in the placebo group experienced minor reactions, the most common of which was pruritis (P = 0.36).

Conclusions

The differences favoring lidocaine were small and nonsignificant, but the trend toward superiority of lidocaine suggests more aggressive phenotyping and applying formulations with greater penetrance may provide clinically meaningful benefit.

Editor’s Perspective

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What This Article Tells Us That Is New
Astrocyte PERK and IRE1 Signaling Contributes to Morphine Tolerance and Hyperalgesia through Upregulation of Lipocalin-2 and NLRP3 Inflammasome in the Rodent Spinal Cord
Authors: Wang Bing , Wang Li-Na , Wu Bin , Guo Ran , Zhang Li , Zhang Jiang-Tao , Wang Zhi-Hong , Wu Feng , Feng Yu , Liu Hong , Jin Xiao-Hong , Miao Xiu-Hua , Liu Tong
Published: December 2023

Background

Endoplasmic reticulum stress plays a crucial role in the pathogenesis of neuroinflammation and chronic pain. This study hypothesized that PRKR-like endoplasmic reticulum kinase (PERK) and inositol-requiring enzyme type 1 (IRE1) regulate lipocalin-2 (LCN2) and Nod-like receptor family pyrin domain containing 3 (NLRP3) expression in astrocytes, thereby contributing to morphine tolerance and hyperalgesia.

Methods

The study was performed in Sprague–Dawley rats and C57/Bl6 mice of both sexes. The expression of LCN2 and NLRP3 was assessed by Western blotting. The tail-flick, von Frey, and Hargreaves tests were used to evaluate nociceptive behaviors. Chromatin immunoprecipitation was conducted to analyze the binding of activating transcription factor 4 (ATF4) to the promoters of LCN2 and TXNIP. Whole-cell patch-clamp recordings were used to evaluate neuronal excitability.

Results

Pharmacologic inhibition of PERK and IRE1 attenuated the development of morphine tolerance and hyperalgesia in male (tail latency on day 7, 8.0 ± 1.13 s in the morphine + GSK2656157 [10 μg] group vs. 5.8 ± 0.65 s in the morphine group; P = 0.04; n = 6 rats/group) and female (tail latency on day 7, 6.0 ± 0.84 s in the morphine + GSK2656157 [10 μg] group vs. 3.1 ± 1.09 s in the morphine group; P = 0.0005; n = 6 rats/group) rats. Activation of PERK and IRE1 upregulated expression of LCN2 and NLRP3 in vivo and in vitro. Chromatin immunoprecipitation analysis showed that ATF4 directly bound to the promoters of the LCN2 and TXNIP. Lipocalin-2 induced neuronal hyperexcitability in the spinal cord and dorsal root ganglia via melanocortin-4 receptor.

Conclusions

Astrocyte endoplasmic reticulum stress sensors PERK and IRE1 facilitated morphine tolerance and hyperalgesia through upregulation of LCN2 and NLRP3 in the spinal cord.

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What We Already Know about This Topic

What This Article Tells Us That Is New
Cryptococcal Infection Presenting as a Pleural Effusion in a Liver Transplant Recipient
Authors: Al-Kaabneh Basil , Alpizar-Rivas Rodolfo , Chuang Sally , Gupta Purba
Published: December 2023

We report a rare case of a liver transplant recipient who experienced acute respiratory failure early posttransplantation because of cryptococcal pleural effusion. Although cryptococcal disease presenting solely as pleural effusion has been reported in the literature, it is not widely described in liver transplant recipients. Cryptococcal disease usually manifests late in the posttransplant period, whereas our patient was diagnosed with the infection early posttransplant. Diagnosis was made by pleural fluid culture. The initial serum cryptococcal antigen testing was negative. This case demonstrates the potential of subclinical or latent infections in patients with cirrhosis and liver transplant recipients and the importance of considering pleural fluid culture in the diagnostic evaluation of pleural effusions in cirrhotic patients.
Empyema Necessitans Following Bacille Calmette-Guérin Administration for Urothelial Carcinoma
Authors: Amar Maisam , Weber Gabriel , Yassin Rabah , Salah Ola , Mishan Pninit Shaked , Brudenski Maya , Shehade Shereen , Najjar-Debbiny Ronza
Published: December 2023

Background

Bacille Calmette-Guérin wash for urothelial carcinoma is a very common adjuvant treatment with a low potential for serious systemic adverse events. We present a case of a rare serious complication, empyema necessitans, following treatment with BCG.

Case Presentation

A 77-year-old patient with urothelial cancer treated with adjuvant BCG wash developed empyema due to Mycobacterium bovis related to his previous BCG exposure, which progressed to empyema necessitans treated with antituberculosis medications in conjugant with multiple thoracic drainages. Despite treatment, the patient's condition deteriorated slowly leading to death.

Conclusion

Rare adverse events of common treatments should be considered when evaluating a patient, as BCG wash could potentially lead to empyema necessitans.
Gallbladder perforation in acute acalculous vs. calculous cholecystitis: a retrospective comparative cohort study with 10-year single-center experience
Authors: Lee Kyong Joo , Park Se Woo , Park Da Hae , Cha Hye Won , Choi Ana , Koh Dong Hee , Lee Jin , Lee Jung Min , Park Chan Hyuk
Published: December 2023

Background:

Gallstones are a well-known risk factor for acute cholecystitis. However, their role as a risk factor for gallbladder perforation (GBP) remains unclear. Therefore, this study aimed to determine the effect of gallstones on the development of GBP.

Materials and methods:

This large-scale retrospective cohort study enroled consecutive patients who underwent cholecystectomy for acute cholecystitis. The primary endpoint was the role of gallstones as a risk factor for developing GBP. Secondary endpoints included the clinical characteristics of GBP, other risk factors for GBP, differences in clinical outcomes between patients with acalculous cholecystitis (AC) and calculous cholecystitis (CC), and the influence of cholecystectomy timing.

Results:

A total of 4497 patients were included in this study. The incidence of GBP was significantly higher in the AC group compared to the CC group (5.6% vs. 1.0%, P<0.001). However, there were no differences in ICU admission and hospital stay durations. The incidence of overall complications was significantly higher in the AC group than in the CC group (2.2% vs. 1.0%, P<0.001). Patients with AC had a higher risk of developing GBP than those with CC (odds ratio, 5.00; 95% CI, 2.94–8.33). In addition, older age (≥60 years), male sex, comorbidities, poor performance status, and concomitant acute cholangitis were associated with the development of GBP. Furthermore, the incidence of GBP was significantly higher in the delayed cholecystectomy group than in the early cholecystectomy group (2.0% vs. 0.9%, P<0.001).

Conclusions:

AC is a significant risk factor for GBP. Furthermore, early cholecystectomy can significantly reduce GBP-related morbidity and mortality.
Portal venous blood flow velocity is a factor associated with portal venous thrombosis after partial splenic artery embolization in hepatic cirrhosis patients
Authors: Huang Jiaming , Liu Haifeng
Published: December 2023

Objective:

To investigate risk factors for portal venous thrombosis (PVT) after partial splenic artery embolization (PSE) in hepatic cirrhosis patients.

Methods:

The authors retrospectively analyzed 151 hepatic cirrhosis patients with hypersplenism who underwent partial splenic artery embolization between January 2020 and December 2021. The patients were divided into a PVT group and a non-PVT group according to whether they had PVT after PSE. Univariate analyses were performed to select risk factors for PVT after PSE, and multivariate analysis was used to analyze variates with a value of P less than 0.1 in univariate analysis.

Results:

There were 151 patients enroled in the study, with 22 patients in the PVT group and 129 patients in the non-PVT group. There was no significant difference in terms of age, sex, smoking, hypertension, diabetes, Child–Pugh between two groups. White blood cell (WBC) and platelet counts after PSE were significantly higher than those before PSE in both the PVT group and non-PVT group. Univariate analysis showed that portal venous blood flow velocity, ligation of oesophageal varices and WBC after PSE were found to have a P value less than 0.1. Multivariate analysis showed that portal venous blood flow velocity was a factor associated with PVT after PSE.

Conclusion:

Portal venous blood flow velocity was a factor associated with PVT after PSE. Portal venous blood flow velocity should be considered before patients undergo PSE.
Experiences and Unmet Needs of Adolescent and Young Adult Survivors of a Brain Tumor (Aged 15–39 Years)
Authors: Law Kate , Salam Iram , McCabe Martin G. , van der Veer Sabine N. , Gibson Faith , Yorke Janelle
Published: December 2023

Background

Brain tumors account for 15% of all adolescent and young adult cancers, and survivors are at risk of ongoing late effects that can severely impact their ability to reach independence. Despite follow-up initiatives advocating a personalized approach, survivors continue to experience ongoing sequelae. A better understanding of the survivorship experience is required to ensure services are able to deliver personalized support.

Objective

The aim of this systematic search and meta-ethnography was to identify and synthesize qualitative studies to better understand the experiences, perspectives, and needs of adolescent and young adult brain tumor survivors.

Methods

Five databases were searched using predefined criteria, studies were independently screened by two researchers, and those meeting inclusion criteria were synthesized.

Results

Twenty-seven studies were synthesized, generating 2 main themes, each with subthemes: (1) individual factors impacting resilience, namely, positive coping styles, managing emotions, and family functioning, and (2) cancer-related factors that challenge the individual, namely, living with societal expectations and barriers to coping.

Conclusion

The conceptual framework illustrates the challenges and resilience of survivors along the continuum from adolescence to adulthood, reflecting the needs of this age group in 1 model, despite it being a time of rapid growth. The lack of awareness of potential physical and emotional late effects challenges individual resilience, which is further challenged when significant milestones cannot be reached.

Implications for Practice

There is a role for follow-up services to identify and address unmet needs, provide better information to equip survivors to manage late effects, and support families, particularly those who underwent more intensive treatment.
Retinal Photograph-based Deep Learning System for Detection of Thyroid-Associated Ophthalmopathy
Authors: Jiang Xue , Dong Li , Luo Lihua , Zhang Kai , Li Dongmei
Published: December 2023

Background:

The diagnosis of thyroid-associated ophthalmopathy (TAO) usually requires a comprehensive examination, including clinical symptoms, radiological examinations, and blood tests. Therefore, cost-effective and noninvasive methods for the detection of TAO are needed. This study aimed to establish a deep learning-based system to detect TAO based on retinal photographs.

Materials and methods:

The multicenter observational study included retinal photographs taken from TAO patients and normal participants in 2 hospitals in China. Forty-five-degree retinal photographs, centered on the midpoint between the optic disc and the macula, were captured by trained ophthalmologists. The authors first trained a convolutional neural network model to identify TAO using data collected from one hospital. After internal validation, the model was further evaluated in another hospital as an external validation data set.

Results:

The study included 1182 retinal photographs of 708 participants for model development, and 365 retinal photographs (189 participants) were obtained as the external validation data set. In the internal validation, the area under the receiver operator curve was 0.900 (95% CI: 0.889–0.910) and the accuracy was 0.860 (95% CI: 0.849–0.869). In the external data set, the model reached an area under the curve of 0.747 (95% CI: 0.728–0.763) and achieved an accuracy of 0.709 (95% CI: 0.690–0.724).

Conclusions:

Deep learning-based systems may be promising for identifying TAO in normal subjects using retinal fundus photographs. It may serve as a cost-effective and noninvasive method to detect TAO in the future.
Associated Risk Factors for Extended Operative Time Following Cranial Vault Remodeling for Craniosynostosis: Analysis of the 2012 to 2021 NSQIP-Pediatric Database
Authors: Serrato Paul , Hengartner Astrid C. , Sayeed Sumaiya , Prassinos Alexandre J. , Alperovich Michael , DiLuna Michael , Elsamadicy Aladine A.
Published: December 2023

Study Design:

Retrospective cohort study.

Objectives:

The aim of this study was to identify the factors associated with extended operative time (EOT) for pediatric patients with craniosynostosis undergoing cranial vault remodeling (CVR).

Methods:

A retrospective cohort study was performed using the 2012 to 2021 American College of Surgeons National Surgical Quality Improvement Program Pediatric–-Pediatric database. Pediatric patients below 2 years old with craniosynostosis who underwent CVR were identified using Current Procedural Terminology and International Classification of Diseases-9/10 codes. Patients were dichotomized according to whether they encountered an EOT, which was defined as operative time greater than the 75th percentile for the entire cohort (246 min). Patient demographics, comorbidities, intraoperative variables, postoperative adverse events, and health care resource utilization were assessed. Multivariate logistic regression analysis was utilized to identify predictors of EOT and length of stay.

Results:

In the cohort of 9817 patients undergoing CVR, 24.3% experienced EOT. The EOT cohort was significantly older and less likely to be non-Hispanic White. Patient comorbidities and surgical adverse events were more frequent among the EOT cohort, including proportions of postoperative surgical site infections. Independent predictors for EOT included age, racial identity, weight, and a higher American Society of Anesthesiologists classification. EOT was found to be an independent predictor for prolonged hospitalization EOT [adjusted odds ratios: 0.78 (0.44–1.13), P<0.001].

Conclusions:

This study demonstrates that age, race, and comorbidities contribute to EOT after CVR for craniosynostosis. EOT is independently associated with a longer length of stay. Additional investigations to further understand the risk factors and impacts of extended EOT are warranted to improve patient outcomes.
SOS1 inhibition enhances the efficacy of and delays resistance to G12C inhibitors in lung adenocarcinoma
Authors: Daley Brianna R , Sealover Nancy E , Sheffels Erin , Hughes Jacob M. , Gerlach Daniel , Hofmann Marco H , Kostyrko Kaja , Mair Barbara , Linke Amanda , Beckley Zaria , Frank Andrew , Dalgard Clifton , Kortum Robert L
Published: December 2023

Clinical effectiveness of KRAS G12C inhibitors (G12Cis) is limited both by intrinsic and acquired resistance, necessitating the development of combination approaches. We found that targeting proximal receptor tyrosine kinase (RTK) signaling using the SOS1 inhibitor (SOS1i) BI-3406 both enhanced the potency of and delayed resistance to G12Ci treatment, but the extent of SOS1i effectiveness was modulated by both SOS2 expression and the specific mutational landscape. SOS1i enhanced the efficacy of G12Ci and limited rebound RTK/ERK signaling to overcome intrinsic/adaptive resistance, but this effect was modulated by SOS2 protein levels. Survival of drug-tolerant persister (DTP) cells within the heterogeneous tumor population and/or acquired mutations that reactivate RTK/RAS signaling can lead to outgrowth of tumor initiating cells (TICs) that drive therapeutic resistance. G12Ci drug tolerant persister cells showed a 2-3-fold enrichment of TICs, suggesting that these could be a sanctuary population of G12Ci resistant cells. SOS1i re-sensitized DTPs to G12Ci and inhibited G12C-induced TIC enrichment. Co-mutation of the tumor suppressorKEAP1limits the clinical effectiveness of G12Cis, andKEAP1andSTK11deletion increased TIC frequency and accelerated the development of acquired resistance to G12Ciin situ. SOS1i both delayed acquired G12Ci resistance and limited the total number of resistant colonies regardless ofKEAP1andSTK11mutational status. These data suggest that SOS1i could be an effective strategy to both enhance G12Ci efficacy and prevent G12Ci resistance regardless of co-mutations.

Significance

The SOS1 inhibitor BI-3406 both inhibits intrinsic/adaptive resistance and targets drug tolerant persister cells to limit the development of acquired resistance to clinical KRASG12Cinhibitors in lung adenocarcinoma cells.