bluuebunny/crossref_metadata_2025 huggingface dataset:
Near wake of the X-Rotor vertical-axis wind turbine
Authors: Bensason David , Sciacchitano Andrea , Ferreira Carlos
Published: May 2023

In the present study, the near wake of a novel vertical-axis wind turbine known as the X-Rotor is experimentally investigated. Particle image velocimetry is used to measure the phase-locked flowfield at several streamwise locations within the rotor’s volume of rotation. The results show a clear impact of coned blades on the streamwise and axial induction fields as well as the local presence of vorticity structures. A notable counteraction of the average expansion of the wake in the axial direction is observed stemming from the shed and tip vorticity of the coned blades. As a result, an axial contraction and radial expansion in the wake can be observed across several phase and cross-stream combinations as well as a consistent asymmetry in streamwise flow. These results encourage the development and validation of numerical models that can account for the three-dimensional induction field of the X-Rotor as well as a further study into the far wake and farm-level installation of vertical-axis wind turbines.
Full-scale validation of optimal axial induction control of a row of turbines at Lillgrund wind farm
Authors: Bossanyi Ervin , Larsen Gunner C. , Pedersen Mads M.
Published: May 2023

We present a full-scale validation study of an optimal power open-loop wind farm control schedule (WFCS) using a full row of turbines (Row-A) at the Lillgrund offshore wind farm as the demonstration case. The derived WFCS is conditioned on the ambient wind speed and wind direction. The WFCS’s are developed using the DNV and DTU numerical models LongSim and Fuga. Prior to implementation, the developed optimal controllers are tested by comparing LongSim results, based on Fuga optimized input, with Fuga optimized results and vice versa. These models are very different in their nature — Fuga being a linearized RANS CFD solver, and LongSim being based on a range of engineering wake models and allowing for unsteady wind farm flow modelling — but nevertheless the overall computed Row-A power gains are reasonably similar. This gives confidence to the developed WFCS’s, even though the two models predict significantly different distributions of the power gains over wind speeds and directions. Based on the numerical analysis, simplified WFCS’s for implementation in the Row-A turbines are developed and tested against the more detailed optimized controller. The test predicts only a small reduction of performance enhancement of the simplified controller compared to the detailed controller, and on this basis it is decided to use the simplified controller for the full-scale turbine implementation. The test, toggling between base control and optimal control in 50-minute successive time slots, has been running since 09-05-2022 and is still ongoing. A huge amount of data is needed to obtain robust statistics for the comparison of measured and numerical data.
Nonlinear Dynamical Analysis of Composite Boring Bar with Nano-carbon Materials
Authors: Zhang Jinfeng , Jia Junlei , Feng Chao , Zhong Peisi
Published: May 2023

Preventing resonance in boring bar vibration is the key to achieve high quality and efficiency. In this paper, using the three-dimensional nonlinear dynamic model of boring process, the cutter bar is simplified as a rotating non planar bending axis, starting from the constitutive relationship and stress displacement relationship of composite materials. Based on Hamilton principle, the nonlinear motion differential equation of cutting process is established. The nonlinear partial differential equations of bending vibration are discretized by Galerkin method. Using the multi-scale method, the frequency response functions of the system in the primary resonance and super resonance are obtained. Using this model, the effects of the length diameter ratio of nano-carbon materials and the content of nano-carbon materials on the vibration frequency response of the boring bar are studied. The results show that the steady vibration amplitude of the cutter bar can be reduced by adding nano-carbon materials to the fiber reinforced polymer composite (FRP) beam.
Flap-lag flutter of high-speed rotating blade section of wind turbine
Authors: Liu Haixiu , Zhang Wenhe , Liu Tingrui
Published: May 2023

This study is to investigate the stall flutter of high-speed rotating blade section of small-scale blades subjected to combined flap-lag motion. The work is motivated by destructive flapwise vibrations of small-scale blades. The aeroelastic governing equations combine a spring-mass-damper equivalent of the structure and a nonlinear aerodynamic model suitable for pure pitching motion. The nonlinear resulting equations are solved by linearization and time-marching approach. The stall flutter stability characteristics are investigated, with flutter suppression discussed.
Study of the Ejection Process of Cold Ejection System with Flexible Cylinder by Corpuscular Method
Authors: Yang Baosheng , Su ZhengYu , Yang Lina , Jiang Yi , Zhao Zhen
Published: May 2023

Cold ejection is widely used in the realm of ejection, but conventional ejection systems can’t adapt to the modern war due to obvious infrared characteristics and high energy consumption, so new ejection system is desired. This work demonstrates a new way of flexible ejection, which is based on control method and corpuscular Method. Firstly, a finite element model of the flexible cylinder ejection system is established. Then, the corpuscular method is applied to study the influence of length and cross-section diameters of the cylinder on the dynamic of ejection process. It is found that the length of flexible cylinder will prolong the time of ejection from 0.72s to 1.01s with length increase from 7.2m to 10.4m. However, the diameter decreases the ejection time. Meanwhile, the velocity increases from 14.37m/s to 15.46m/s with cross-section diameter of cylinder increases from 0.60m to 0.75m. And the maximum overload is bigger 25.9 % than minimum.
Simulation of Flexible Dual-mode Surface Acoustic Wave Resonator for Strain Sensor Application
Authors: Huang Shitian , Luo Wenbo , Lv Lu , Yao Shuai , Wu Chuangui , Zhang Wanli
Published: May 2023

Based on the requirement of flexible electronic devices (FED)such as surface acoustic wave (SAW) sensors, finite element models for material analysis and SAW resonator design were established. Dual-mode of Rayleigh and Horizontal Shear mode on 0ºY cut LiNbO3 thin film was discovered. The influence of BCB thickness and PI substrate on resonant mode was analyzed. The flexible SAW resonator owned high sensitivity both in Rayleigh mode and Horizontal shear mode under tensile stress and compressive stress by simulation.
Dynamic Simulation and Research of Land-Based Missile Tilt Launch Platform
Authors: Wen Xianghua , Jiang Yi , Yan Song , Zhu Qizhang , Ren Ruoyu
Published: May 2023

In order to study the influence of the structural factors of the launch device on the missile tilt projectile dynamics, a dynamic model of the missile tilt launch platform was established based on the finite element method. The effects of shock absorber stiffness, angle between shock absorber and horizontal plane and tilt of the launch device were studied on the missile and launch platform’s ejection response characteristics. The research results show that the greater the rigidity of the shock absorber, the smaller the angle between the shock absorber and the horizontal plane, and the smaller the vibration amplitude of the initial disturbance of the missile and the launch cylinder; when the tilt angle of the launch device is within 6 °, the angle change has a smaller impact on the speed of the missile outlet, and there is a sufficient safety distance between the missile and the launch canister during the launch process. The larger the vibration amplitude of the initial disturbance and the launch tube. The research results can provide a theoretical reference for the design and optimization of the tilted launch platform.
Research on requirement fusion of imaging reconnaissance satellites
Authors: Zhao Yulong , Zhang Yuan , Xu Can , Wang Yan
Published: May 2023

Aiming at the problem of how to improve the requirement satisfaction of multi-point target imaging reconnaissance tasks and the utilization efficiency of satellite resources, a multi-point target imaging reconnaissance requirement fusion method based on genetic optimization is proposed in this paper. Firstly, the basic constraints that can be fused between multi-point targets are analysed, and on this basis, a point-target synthetic observation model is constructed. Secondly, considering the constraints of observation time window, observation angle and transition time between synthetic tasks, a genetic algorithm-based multi-point target requirements fusion method is designed. Finally, through the simulation analysis, it is concluded that with the continuous increase of user requirements, the fusion method based on genetic optimization can still achieve better task satisfaction to the user’s imaging requirements, which greatly improves the use efficiency of imaging satellites.
Combustion Surface Calculation Method of Solid Rocket Propellant Based on Parameterized Volume Boolean Operation
Authors: Sun Ruiyang , Jiang Yi
Published: May 2023

In order to solve the problem of long time consuming and low efficiency in solving the complex combustion surface of solid rocket propellant, a combustion surface calculation method based on parameterized volume Boolean operation was proposed. After the solid model of propellant was created by using 3D modeling software, the parameterized burning surface model was used to perform Boolean difference calculation between the obtained burning surface growth entity and the propellant entity. Through Sensitivity Analysis function, the variation range of parameterized value was set, so as to obtain the burning face value under different burning thickness. In this paper, star shaped charge column is selected to calculate the combustion surface, and the feasibility of the method is verified. This method provides a basis for subsequent combustion surface calculation.
A High Isolation Dual-band WiFi MIMO Antenna Design
Authors: Yuan Kang , Nie Qilei , Zhang Songtao , Peng Lihu , Wang Qinghai , Liu Geng
Published: May 2023

In this paper, a dual-band WiFi MIMO antenna with high isolation is designed. The antenna is F-Type structure, and the resonant points of high frequency and low frequency are mainly controlled by two branches of ‘F’. In order to improve the isolation between antennas, multiple symmetrically distributed slots are introduced on the ground, by adjusting the size and spacing of each group of slots, the effect of 2.4GHz & 5G dual-band decoupling is realized. Through HFSS simulation and optimization, antenna in frequency of 2.4-2.5GHz & 5.2-5.825GHz, S11 meet-10db bandwidth requirements, the isolation between the two ports is higher than 25dB, meet the design requirements.
A Game Coordination Optimization Algorithm
Authors: Zhu Yuyu , Wu Qing’e , Xiao Na , Wang Wenjing
Published: May 2023

In order to solve the problems of information flow and traffic jams, this paper proposes a game coordination optimization algorithm, and gives a coordination optimization model for the communication signal area. A game coordination strategy algorithm is studied using multi-agent technology. This model can make all local area networks and routing ports fully cooperate, so that the communication signals of a certain area can be coordinated and optimized. At the same time, the application of the game coordination optimization algorithm in power grid intelligent communication, control and resource optimization is given. By comparing the communication effect under different coordination probabilities, the simulation results show that the communication effect under high coordination probability has obvious advantages such as high fidelity, low distortion, fast communication speed, and small communication volume. The development of these studies can in turn accelerate the application of game and agent algorithms in various fields.
Application and Implementation of Artificial Intelligence Technology for Intelligent Vehicle
Authors: Guo Yong , Wu Shikai , Wang Yu , Wen ChongBin , Luo Le , Fu Qiang
Published: May 2023

With the development of artificial intelligence (AI) and the advancement of industrial technology, electric vehicles have become the main tools for people’s travel mobility. In order to cope with the faster rhythms of life and to meet people’s aspirations to live a better life, the integration of AI technology and automobiles is becoming closer and more popular. In this study, the transplantation of TensorFlow and Keras architecture on the embedded platform is implemented. An intelligent tracking car is designed and completed. It takes one i.MX RT1064 as the core processor, two electromagnetic rods as the tracking sensors, a steering gear and a motor as the motion control system, and has the application of neural network algorithm in the training and operation stages. The application of convolutional neural networks to the electromagnetic tracking of intelligent car is realized. Through the research of this smart car model, it helps to deeply understand the key technologies and automotive automation control systems of smart car manufacturing, and lay a solid foundation for designing practical smart cars in the future
Experimental and simulation research on the electrical characteristics of 1553B bus system
Authors: Feng Shuai , Wang Lei , Wang Yan , Hu Yusang , Cai Biao , Yu Dan
Published: May 2023

An experimental system of 1553B bus is build, and several key parameters of the system are measured. A simulation method for the electrical characteristics of 1553B system using Matlab/Simulink is proposed. The experimental results and the simulation results are compared, and the comparison shows the effectiveness and correctness of the simulation method. Then, the electrical characteristics of 1553B bus system with different structural configurations are simulated, and qualitative suggestions for the design of the 1553B bus system are given.
Mechanical and microstructure evaluation of novel hybrid TiB2/B4C aluminium metal matrix composite
Authors: Senthilnathan T , Balachandar K
Published: May 2023

In the current study, a novel approach that integrated in situ and ex situ reinforcement techniques was used to develop a hybrid AA7475 aluminium metal matrix composite (MMC). The primary objective of this study was to explore the viability of producing in situ TiB2 particles and adding ex situ B4C particles as reinforcements in the same melt of the aluminium alloy AA7475, with the intention of using these ceramic fillers to improve the mechanical properties of bare AA7475. For in situ particle synthesis, salts such as K2TiF6 and KBF4 were used and for ex situ, B4C particles are utilized. The aluminium MMC was prepared using stir casting method and characterized using ASTM standards. For comparison, composite with only in situ TiB2 particles and composite with only ex situ B4C particles were also fabricated. According to the results, the highest tensile strength of 156.57 MPa was achieved for the hybrid composite made using 5wt% of B4C and TiB2. Similarly, the highest hardness of 144.67 HV was observed for the same. However, the presence of both TiB2 and B4C improved the hardness together. The microstructure shows highly refined phases of the matrix and also the formation of precipitates and reinforcements clearly. The EDAX and XRD confirm the intermetallics formation and dispersion of particles within the matrix material. This aluminium composite with improved properties could be used in automotive, aircraft and in defense sectors where lightweight and high strength materials are required.
Community structure of soil mites under different crops and its response to environmental factors in the buffer zone of Shibing Karst World Natural Heritage
Authors: Yin Xiumei , Gong Tong , Liu Wenjun , Chen Hu , Fei Yifan
Published: May 2023

To reveal the differences in the community structure of soil mites under different crop environments in the buffer zone of the Shibing Karst World Natural Heritage Site, soil mites from corn fields (CF), pear tree lands (PL), tobacco fields (TF), grape fields (GF), and plum gardens (PG) were collected in the buffer zone in January 2022. Through the identification of mite specimens and data analysis, differences in the number of families, genera, individuals, individual density, diversity, similarity of communities, ecological groups of oribatid mites, and responses to environmental factors of soil mites under different crop environments were determined. The results showed that: (1) A total of 6941 soil mites were captured in the study area, belonging to 130 genera, 75 families, and 3 orders. The number of soil mite genera (CF and TF > PL > PG > GF) and number of soil mite individuals (PG > PL > GF > TF > CF) showed characteristics of differential distribution and surface soil aggregation in the five habitats. (2) Scheloribates, Protorobotritia, and Tectocepheus were the dominant genera in the study area. Lohmannia, Scheloribates, and Tectocepheus, representative species that indicate a good soil environment, were distributed in the sample plots of CF, PL, and PG to varying degrees, indicating that the ecological environment of these three crops was healthy. (3) The diversity index of PG was the highest, and similarity analysis of the five habitats revealed that they were at a medium level of similarity. (4) The ecological groups of oribatid mites in the different crop environments were dominated by the overall (O) type, which is a combination of Macropylina, Gymnonota, and Poronota. (5) The community structure of soil mites was sensitive to bulk density (BD), natural water content (NWC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available potassium (AK), and soil organic matter (SOM). Based on the above results, there were differences in the community structures of soil mites under different crop environments in the study area. The identification of the dominant mite genera can preliminarily indicate the environmental conditions of different crops, and a special correlation exists between the community structure of mites and environmental factors. Studying the community structure of mites in different crop environments in the Shibing Karst World Natural Heritage Site buffer zone is important in ensuring the ecological protection and sustainable development of the buffer zone. Furthermore, the results of this study support the role of the buffer zone as an ecological protection barrier for the heritage site.
Birth Weight in Consecutive Pregnancies and Maternal Cardiovascular Disease Mortality Among Spontaneous and Iatrogenic Term Births: A Population-Based Cohort Study
Authors: Sima Yeneabeba Tilahun , Skjaerven Rolv , Kvalvik Liv Grimstvedt , Morken Nils-Halvdan , Klungsøyr Kari , Mannseth Janne , Sørbye Linn Marie
Published: May 2023

Knowledge on the association between offspring birth weight and long-term risk of maternal cardiovascular disease (CVD) mortality is often based on firstborn infants without consideration of women’s consecutive births. We studied long-term CVD mortality according to offspring birth weight patterns among women with spontaneous and iatrogenic term deliveries in Norway (1967–2020). We constructed birth weight quartiles (Qs) by combining standardized birth weight with gestational age in quartiles (Q1, Q2/Q3, and Q4) for the women’s first 2 births. Mortality was estimated using Cox regression and expressed as hazard ratios (HRs) with 95% confidence intervals (CIs). Changes in offspring birth weight quartiles were associated with long-term maternal CVD mortality. Compared with women who had 2 term infants in Q2/Q3, women with a first offspring in Q2/Q3 and a second in Q1 had higher mortality risk (HR = 1.33, 95% CI: 1.18, 1.50), while risk was lower if the second offspring was in Q4 (HR = 0.78, 95% CI: 0.67, 0.91). The risk increase associated with having a first infant in Q1 was eliminated if the second offspring was in Q4 (HR = 0.99, 95% CI: 0.75, 1.31). These patterns were similar for women with iatrogenic and spontaneous deliveries. Inclusion of information from subsequent births revealed heterogeneity in maternal CVD mortality which was not captured when using only information based on the first offspring.
NTpred: a robust and precise machine learning framework forin silicoidentification of Tyrosine nitration sites in protein sequences
Authors: Datta Sourajyoti , Nabeel Asim Muhammad , Dengel Andreas , Ahmed Sheraz
Published: May 2023

Post-translational modifications (PTMs) either enhance a protein’s activity in various sub-cellular processes, or degrade their activity which leads toward failure of intracellular processes. Tyrosine nitration (NT) modification degrades protein’s activity that initiates and propagates various diseases including neurodegenerative, cardiovascular, autoimmune diseases and carcinogenesis. Identification of NT modification supports development of novel therapies and drug discoveries for associated diseases. Identification of NT modification in biochemical labs is expensive, time consuming and error-prone. To supplement this process, several computational approaches have been proposed. However these approaches fail to precisely identify NT modification, due to the extraction of irrelevant, redundant and less discriminative features from protein sequences. This paper presents the NTpred framework that is competent in extracting comprehensive features from raw protein sequences using four different sequence encoders. To reap the benefits of different encoders, it generates four additional feature spaces by fusing different combinations of individual encodings. Furthermore, it eradicates irrelevant and redundant features from eight different feature spaces through a Recursive Feature Elimination process. Selected features of four individual encodings and four feature fusion vectors are used to train eight different Gradient Boosted Tree classifiers. The probability scores from the trained classifiers are utilized to generate a new probabilistic feature space, which is used to train a Logistic Regression classifier. On the BD1 benchmark dataset, the proposed framework outperforms the existing best-performing predictor in 5-fold cross validation and independent test evaluation with combined improvement of 13.7% in MCC and 20.1% in AUC. Similarly, on the BD2 benchmark dataset, the proposed framework outperforms the existing best-performing predictor with combined improvement of 5.3% in MCC and 1.0% in AUC. NTpred is publicly available for further experimentation and predictive use at: https://sds_genetic_analysis.opendfki.de/PredNTS/.
Accelerated nanopore basecalling with SLOW5 data format
Authors: Samarakoon Hiruna , Ferguson James M , Gamaarachchi Hasindu , Deveson Ira W
Published: May 2023

Motivation

Nanopore sequencing is emerging as a key pillar in the genomic technology landscape but computational constraints limiting its scalability remain to be overcome. The translation of raw current signal data into DNA or RNA sequence reads, known as ‘basecalling’, is a major friction in any nanopore sequencing workflow. Here, we exploit the advantages of the recently developed signal data format ‘SLOW5’ to streamline and accelerate nanopore basecalling on high-performance computing (HPC) and cloud environments.

Results

SLOW5 permits highly efficient sequential data access, eliminating a potential analysis bottleneck. To take advantage of this, we introduce Buttery-eel, an open-source wrapper for Oxford Nanopore’s Guppy basecaller that enables SLOW5 data access, resulting in performance improvements that are essential for scalable, affordable basecalling.

Availability and implementation

Buttery-eel is available at https://github.com/Psy-Fer/buttery-eel.
3DMolMS: prediction of tandem mass spectra from 3D molecular conformations
Authors: Hong Yuhui , Li Sujun , Welch Christopher J , Tichy Shane , Ye Yuzhen , Tang Haixu
Published: May 2023

Motivation

Tandem mass spectrometry is an essential technology for characterizing chemical compounds at high sensitivity and throughput, and is commonly adopted in many fields. However, computational methods for automated compound identification from their MS/MS spectra are still limited, especially for novel compounds that have not been previously characterized. In recent years, in silico methods were proposed to predict the MS/MS spectra of compounds, which can then be used to expand the reference spectral libraries for compound identification. However, these methods did not consider the compounds’ 3D conformations, and thus neglected critical structural information.

Results

We present the 3D Molecular Network for Mass Spectra Prediction (3DMolMS), a deep neural network model to predict the MS/MS spectra of compounds from their 3D conformations. We evaluated the model on the experimental spectra collected in several spectral libraries. The results showed that 3DMolMS predicted the spectra with the average cosine similarity of 0.691 and 0.478 with the experimental MS/MS spectra acquired in positive and negative ion modes, respectively. Furthermore, 3DMolMS model can be generalized to the prediction of MS/MS spectra acquired by different labs on different instruments through minor fine-tuning on a small set of spectra. Finally, we demonstrate that the molecular representation learned by 3DMolMS from MS/MS spectra prediction can be adapted to enhance the prediction of chemical properties such as the elution time in the liquid chromatography and the collisional cross section measured by ion mobility spectrometry, both of which are often used to improve compound identification.

Availability and implementation

The codes of 3DMolMS are available at https://github.com/JosieHong/3DMolMS and the web service is at https://spectrumprediction.gnps2.org.
NHGNN-DTA: a node-adaptive hybrid graph neural network for interpretable drug–target binding affinity prediction
Authors: He Haohuai , Chen Guanxing , Chen Calvin Yu-Chian
Published: May 2023

Motivation

Large-scale prediction of drug–target affinity (DTA) plays an important role in drug discovery. In recent years, machine learning algorithms have made great progress in DTA prediction by utilizing sequence or structural information of both drugs and proteins. However, sequence-based algorithms ignore the structural information of molecules and proteins, while graph-based algorithms are insufficient in feature extraction and information interaction.

Results

In this article, we propose NHGNN-DTA, a node-adaptive hybrid neural network for interpretable DTA prediction. It can adaptively acquire feature representations of drugs and proteins and allow information to interact at the graph level, effectively combining the advantages of both sequence-based and graph-based approaches. Experimental results have shown that NHGNN-DTA achieved new state-of-the-art performance. It achieved the mean squared error (MSE) of 0.196 on the Davis dataset (below 0.2 for the first time) and 0.124 on the KIBA dataset (3% improvement). Meanwhile, in the case of cold start scenario, NHGNN-DTA proved to be more robust and more effective with unseen inputs than baseline methods. Furthermore, the multi-head self-attention mechanism endows the model with interpretability, providing new exploratory insights for drug discovery. The case study on Omicron variants of SARS-CoV-2 illustrates the efficient utilization of drug repurposing in COVID-19.

Availability and implementation

The source code and data are available at https://github.com/hehh77/NHGNN-DTA.
Intraoperative bowel perfusion assessment methods and their effects on anastomotic leak rates: meta-analysis
Authors: Renna Maxwell S , Grzeda Mariusz T , Bailey James , Hainsworth Alison , Ourselin Sebastien , Ebner Michael , Vercauteren Tom , Schizas Alexis , Shapey Jonathan
Published: May 2023

Background

Anastomotic leak is one of the most feared complications of colorectal surgery, and probably linked to poor blood supply to the anastomotic site. Several technologies have been described for intraoperative assessment of bowel perfusion. This systematic review and meta-analysis aimed to evaluate the most frequently used bowel perfusion assessment modalities in elective colorectal procedures, and to assess their associated risk of anastomotic leak. Technologies included indocyanine green fluorescence angiography, diffuse reflectance spectroscopy, laser speckle contrast imaging, and hyperspectral imaging.

Methods

The review was preregistered with PROSPERO (CRD42021297299). A comprehensive literature search was performed using Embase, MEDLINE, Cochrane Library, Scopus, and Web of Science. The final search was undertaken on 29 July 2022. Data were extracted by two reviewers and the MINORS criteria were applied to assess the risk of bias.

Results

Some 66 eligible studies involving 11 560 participants were included. Indocyanine green fluorescence angiography was most used with 10 789 participants, followed by diffuse reflectance spectroscopy with 321, hyperspectral imaging with 265, and laser speckle contrast imaging with 185. In the meta-analysis, the total pooled effect of an intervention on anastomotic leak was 0.05 (95 per cent c.i. 0.04 to 0.07) in comparison with 0.10 (0.08 to 0.12) without. Use of indocyanine green fluorescence angiography, hyperspectral imaging, or laser speckle contrast imaging was associated with a significant reduction in anastomotic leak.

Conclusion

Bowel perfusion assessment reduced the incidence of anastomotic leak, with intraoperative indocyanine green fluorescence angiography, hyperspectral imaging, and laser speckle contrast imaging all demonstrating comparable results.
Localized adaptive waveform inversion: regularizations for Gabor deconvolution and 3-D field data application
Authors: Yong Peng , Brossier Romain , Métivier Ludovic , Virieux Jean
Published: May 2023

Recently, we have developed a localized adaptive waveform inversion (LAWI) method to tackle the cycle-skipping issue in velocity reconstruction through seismic waveform inversion. The LAWI method employs a local matching filter, computed using Gabor deconvolution, to measure the instantaneous time-shift between observed and calculated data. Unlike the adaptive waveform inversion (AWI) approach, the LAWI method can take the non-stationarity between observed and calculated data into account. In this work, we investigate two types of regularization based on prior information about the expected filter, which could be a minimum-norm filter or a delta-shape filter, with regard to their effects on the robustness and resolution of inversion. We demonstrate on synthetic data the advantages and disadvantages of these two types of prior information, where the delta-type LAWI may handle multiple observed phases not initially predicted by the starting velocity model. Therefore, we apply the delta-type LAWI to a high-quality 3-D field data set in the North Sea, eliminating the need for data-windowing tuning, which can be tedious and time-consuming for 3-D data. Under different workflows with varying reliable initial models and frequency bands of the pressure data considered, we show that the LAWI approach is robust, effective and efficient for reconstructing the P-wave velocity, while other approaches such as AWI and graph-space optimal-transport method may require meticulous data-tuning strategies to converge to the correct model. Well logs and data fits, primarily from early arrivals, give us confidence that this LAWI approach could be applied to various acquisitions and subsurface targets, thanks to its phase-driven principle.
Checkmate: Chess Artifacts and Artworks Made and Played in Extremis
Authors: Perry Rachel , Jackl Klara , Lochekhina Galina
Published: May 2023

A game of war, chess was played and pictured in a time of war by men and women, Jews and non-Jews in hiding, in the ghettos, and even behind the barbed wire of the transit, concentration, and extermination camps across Nazi-occupied Europe. Throughout the Second World War, instead of “throwing the game” and giving up, victims of National Socialism devised ingenious ways to improvise chess sets out of found materials and detritus—carved wood, folded paper, etched tin, and modeled bread. They also drew and painted chess games to document and allegorize their lives in extremis. Through a close reading of chess artifacts and artworks, this article reveals how access to materials and time, status within camp hierarchies, ethnic and national identities, and wartime experiences impacted the various ways these groups used the game of chess under difficult playing conditions. Insisting upon the central role of creativity and play, it argues that both material artifacts and artwork inform our knowledge of how individuals living under Nazi oppression thought and felt.
Molecular ecology of highest priority critically important antibiotic resistant Escherichia coli from mammals housed at an urban zoo
Authors: Sealey Jordan E , Saunders Richard , Horspool Teresa , Barrows Michelle G , Avison Matthew B
Published: May 2023

Objectives

Zoos are environments where species of highly valued animals are kept largely separated from others and the wider world. We report the molecular ecology of critically important antibiotic resistant (ABR) Escherichia coli carried by 28 mammalian species housed in a zoo located in an urban residential district.

Methods

Over 3 months we collected 167 faecal samples from captive mammals and processed for E. coli resistant to third-generation cephalosporins (3GC-R) and fluoroquinolones (FQ-R). Isolates were sequenced using Illumina.

Results

We identified high rates of faecal sample-level positivity, with 50%, 57% and 36% of mammalian species excreting 3GC-R, FQ-R or dual 3GC-R/FQ-R E. coli, respectively. Isolates represented multiple ST and ABR mechanisms; CTX-M-15 and CMY-2 dominated for 3GC-R, and target-site mutation caused 75% of FQ-R. We identified multiple examples of ABR E. coli transmission between mammalian species in separate enclosures, and a variant of the epidemic plasmid pCT within the zoo. There was no evidence for ABR E. coli leaving the zoo, based on comparative analysis with E. coli from humans, cattle and dogs isolated from the 50 × 50 km region in which the zoo is located. Amoxicillin/clavulanate was the most widely used antibiotic in the zoo, and we identified four widely disseminated amoxicillin/clavulanate resistance mechanisms, including a previously unreported inhibitor-resistant TEM, and the carbapenemase OXA-181.

Conclusions

We conclude that the zoo studied here is a ‘melting pot’ for the selection and circulation of 3GC-R and FQ-R E. coli, but these circulating E. coli appear captive within the zoo.
Differential response to antibiotic therapy in staphylococcal infective endocarditis: contribution of an ex vivo model
Authors: Lalanne Sébastien , Cattoir Vincent , Guerin François , Verdier Marie-Clémence , Revest Matthieu
Published: May 2023

Objectives

Staphylococcal infective endocarditis (IE) remains a hard-to-treat infection with high mortality. Both the evaluation of new innovative therapies and research on alternative models mimicking human IE are therefore urgently needed to improve the prognosis of patients with diagnosed IE. Dalbavancin is a novel anti-staphylococcal lipoglycopeptide but there are limited data supporting its efficacy on biofilm infections. This antibiotic could be an alternative to current therapies for the medical treatment of IE but it needs to be further evaluated.

Methods

Here we developed an original ex vivo model of Staphylococcus aureus IE on human heart valves and assessed biofilm formation on them. After validating the model, the efficacy of two antistaphylococcal antibiotics, vancomycin and dalbavancin, was compared by measuring and visualizing their respective ability to inhibit and eradicate late-formed biofilm.

Results

Determination of the minimum biofilm inhibitory (MbIC) and eradicating (MbEC) concentrations in our ex vivo model identified dalbavancin as a promising drug with much lower MbIC and MBEC than vancomycin (respectively <0.01 versus 28 mg/L and 0.03 versus 32 mg/L).

Conclusions

These data highlight a strong bactericidal effect of dalbavancin, particularly on an infected heart valve compared with vancomycin. Dalbavancin could be a realistic alternative treatment for the management of staphylococcal IE.
Impact of a prospective audit and feedback antimicrobial stewardship programme on carbapenem consumption: a quasi-experimental study (IPANEMA study)
Authors: Ronda Mar , Padullés Ariadna , Grau Imma , Tubau Fe , Satorra Pau , Shaw Evelyn , Vigués Francesc , Carratalà Jordi
Published: May 2023

Objectives

To test the hypothesis that a prospective audit and feedback (PAF) intervention combined with electronic tools will reduce carbapenem use without negatively affecting patient outcomes.

Methods

A quasi-experimental, pre-intervention and intervention study was performed conducted in the urology department of a university hospital. The intervention involved implementing a PAF within an antimicrobial stewardship programme with the aid of an electronic tool. The primary outcome was carbapenem use, assessed by DDD/100 patient-days (PD). Secondary outcomes included evaluating the effect of the intervention on overall antibiotic use measured by DDD/100 PD and days of therapy (DOT)/100 PD, as well as patient safety. The chi-squared test or t-test was used, and the Poisson model was employed to assess the association between the intervention and outcomes.

Results

A 9% decrease in carbapenem DDD/100 PD was observed during the intervention period (IR = 0.91; 95% CI = 0.85–0.97, P = 0.007). The proportion of patients who received carbapenem treatment dropped from 17.8% to 16.5% [incidence ratio (IR) = 0.95; 95% CI = 0.86–2.05, P = 0.31]. Carbapenem DOT/100 PD decreased from 12.4 to 11.0 (IR = 0.89; 95% CI = 0.83–0.94, P < 0.001). Overall antibiotic DDD/100 PD decreased by 3% (IR = 0.97; 95% CI = 0.94–0.99, P = 0.001) and DOT/100 PD by 7% (IR = 0.93; 95% CI = 0.91–0.95, P < 0.001). The incidence of infections caused by carbapenemase-producing microorganisms, Enterococcus faecium bacteraemia and Clostridioides difficile-associated diarrhoea episodes was similar in the pre-intervention and intervention periods. ESBL incidence rate decreased, but the differences were not statistically significant (3.94/1000 PD versus 2.88/1000 PD, P = 0.111). Length of hospital stay, in-hospital all-cause mortality, and 30 day readmission incidence remained unchanged.

Conclusions

The implementation of PAF combined with an electronic tool was an effective and safe intervention for reducing carbapenem use.
High-level in vitro resistance to gentamicin acquired in a stepwise manner in Neisseria gonorrhoeae
Authors: Golparian Daniel , Jacobsson Susanne , Holley Concerta L , Shafer William M , Unemo Magnus
Published: May 2023

Objectives

Gentamicin is used in several alternative treatments for gonorrhoea. Verified clinical Neisseria gonorrhoeae isolates with gentamicin resistance are mainly lacking and understanding the mechanisms for gonococcal gentamicin resistance is imperative. We selected gentamicin resistance in gonococci in vitro, identified the novel gentamicin-resistance mutations, and examined the biofitness of a high-level gentamicin-resistant mutant.

Methods

Low- and high-level gentamicin resistance was selected in WHO X (gentamicin MIC = 4 mg/L) on gentamicin-gradient agar plates. Selected mutants were whole-genome sequenced. Potential gentamicin-resistance fusA mutations were transformed into WT strains to verify their impact on gentamicin MICs. The biofitness of high-level gentamicin-resistant mutants was examined using a competitive assay in a hollow-fibre infection model.

Results

WHO X mutants with gentamicin MICs of up to 128 mg/L were selected. Primarily selected fusA mutations were further investigated, and fusAR635L and fusAM520I + R635L were particularly interesting. Different mutations in fusA and ubiM were found in low-level gentamicin-resistant mutants, while fusAM520I was associated with high-level gentamicin resistance. Protein structure predictions showed that fusAM520I is located in domain IV of the elongation factor-G (EF-G). The high-level gentamicin-resistant WHO X mutant was outcompeted by the gentamicin-susceptible WHO X parental strain, suggesting lower biofitness.

Conclusions

We describe the first high-level gentamicin-resistant gonococcal isolate (MIC = 128 mg/L), which was selected in vitro through experimental evolution. The most substantial increases of the gentamicin MICs were caused by mutations in fusA (G1560A and G1904T encoding EF-G M520I and R635L, respectively) and ubiM (D186N). The high-level gentamicin-resistant N. gonorrhoeae mutant showed impaired biofitness.
A Comprehensive Quality Evaluation of Cimicifugae Rhizoma Using UPLC–Q-Orbitrap-MS/MS Coupled with Multivariate Chemometric Methods
Authors: Ma Zi Cheng , Liu Mei Qi , Liu Guo Qiang , Zhou Zhen Yu , Ren Xiao Liang , Sun Lili , Wang Meng
Published: May 2023

Background

Cimicifugae Rhizoma, known in Chinese as Shengma, is a common medicinal material in traditional Chinese medicine (TCM), mainly used for treating wind-heat headaches, sore throat, uterine prolapse, and other diseases.

Objectives

An approach using a combination of ultra-performance liquid chromatography (UPLC), MS, and multivariate chemometric methods was designed to assess the quality of Cimicifugae Rhizoma.

Methods

All materials were crushed into powder and the powdered sample was dissolved in 70% aqueous methanol for sonication. Chemometric methods, including hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least-squares discriminant analysis (OPLS-DA), were adopted to classify and perform a comprehensive visualization study of Cimicifugae Rhizoma. The unsupervised recognition models of HCA and PCA obtained a preliminary classification and provided a basis for classification. In addition, we constructed a supervised OPLS-DA model and established a prediction set to further validate the explanatory power of the model for the variables and unknown samples.

Results

Exploratory research found that the samples were divided into two groups, and the differences were related to appearance traits. The correct classification of the prediction set also demonstrated a strong predictive ability of the models for new samples. Subsequently, six chemical makers were characterized by UPLC–Q-Orbitrap-MS/MS, and the content of four components was determined. The results of the content determination revealed the distribution of representative chemical markers caffeic acid, ferulic acid, isoferulic acid, and cimifugin in two classes of samples.

Conclusions

This strategy can provide a reference for assessing the quality of Cimicifugae Rhizoma, which is significant for the clinical practice and QC of Cimicifugae Rhizoma.

Highlights

The HCA, PCA and OPLS-DA models visually classify Cimicifugae Rhizoma by appearance traits and obtain the chemical markers that influence the classification. The training and prediction sets were built to demonstrate the accuracy of the classification. Advanced UPLC-Q-Orbitrap-MS/MS technology provides powerful elucidation of critical chemical markers.
Comparison of Diagnostic Sensitivity and Procedure-Related Pain of Concurrent Ultrasound-guided Fine-needle Aspiration and Core-needle Biopsy of Axillary Lymph Nodes in Patients with Suspected or Known Breast Cancer
Authors: Winkler Nicole , Buxton Jace , Freer Phoebe , Raps Evan , Barraza Gonzalo , Boucher Ken , Riegert Joanna , Factor, Rachel
Published: May 2023

Objective

Conflicting data exist on the diagnostic sensitivity of core-needle biopsy (CNB) compared to fine-needle aspiration (FNA) in the evaluation of axillary lymph node metastasis from breast cancer. Our purpose was to evaluate the sensitivity of CNB and FNA using subsequent axillary surgery as the gold standard and to compare the patients’ subjective pain levels for each biopsy method.

Methods

This IRB-approved prospective study enrolled 140 patients from February 2014 to May 2019 with known or suspected breast cancer. Patients underwent both US-guided FNA and 14-gauge CNB of the same node with clip placement and rated their pain level using a verbal numerical rating scale of 0 to 10. The diagnostic sensitivities were determined by pathology of the surgically excised lymph node using the McNemar test of correlated proportions. Changes in pain scores for CNB and FNA were determined using the Wilcoxon rank sum test.

Results

A total of 94 patients had confirmatory excision of the biopsied node with nodal metastasis detected in 71.3% (67/94). The sensitivity of CNB for detection of nodal metastasis was 95.5% (64/67), while the sensitivity of FNA was 67.2% (45/67) (P < 0.05). Overall pain score ratings for CNB increased by 0.6 from baseline on an 11-point numerical rating scale, while overall pain score rating for FNA decreased by 0.2 from baseline (P < 0.05).

Conclusion

Our study demonstrates that 14-gauge CNB has superior sensitivity for detection of axillary nodal metastases and mildly increased pain compared with 25-gauge FNA in patients with breast cancer.
The Impact of Increased Access to Telemedicine
Authors: Zeltzer Dan , Einav Liran , Rashba Joseph , Balicer Ran D
Published: May 2023

We estimate the impact of increased access to telemedicine following widespread adoption during the March–April 2020 COVID-19 lockdown period. We focus on the post-lockdown period, which was characterized by near-complete reopening. Using a difference-in-differences framework, we compare primary care episodes before and after the lockdown between patients with high and low access to telemedicine, as defined by their primary care physician adoption. Our results show that access to telemedicine leads to slightly more primary care visits but lower spending. Visits involve fewer prescriptions and more follow-ups, but we find no evidence of missed diagnoses or adverse outcomes. Results suggest that telemedicine does not compromise care quality or raise costs.
NAA10 overexpression dictates distinct epigenetic, genetic, and clinicopathological characteristics in adult gliomas
Authors: Le Minh-Khang , Vuong Huy Gia , Nguyen Thao T T , Kondo Tetsuo
Published: May 2023

NAA10 is a novel biomarker of cancer progression. The oncogenic and biological mechanisms of NAA10 in human malignancies are controversial and remain to be elucidated. Herein, we investigated the biological and clinicopathological implications of NAA10 gene expression in adult gliomas. We collected data from The Human Cancer Genome Atlas (TCGA) database, including patients from TCGA-GBM and TCGA-LGG projects. In total, there were 666 patients from the 2 projects (513 and 153 from TCGA-LGG and TCGA-GBM, respectively). Different analyses (pathway, DNA methylation, and survival analyses) require further specific case eliminations. Based on NAA10 expression, we divided 666 tumors into 2 subgroups: NAA10-high and NAA10-low glioma. There were higher activities of cell proliferation, metabolic reprogramming, DNA repair, angiogenesis, epithelial-mesenchymal transition, TNF-α, IL6/JAK/STAT6, mTORC1 signaling, and MYC targets in NAA10-high glioma, while P53, TGF-β, Wnt, and Hedgehog pathways were highly expressed by NAA10-low gliomas. t-distributed stochastic neighbors embedding dimension reduction of DNA methylation also showed a high distribution of NAA10-high gliomas in distinct clusters. Survival analyses showed that high NAA10 expression was an independent prognostic factor. NAA10 expression dictated epigenetic, genetic, and clinicopathological differences in adult glioma. Further studies are required to investigate the detailed NAA10 oncogenic mechanisms and to validate NAA10 immunohistochemistry.