Processing Software Research Articles

FindGSEP: Estimating genome size of polyploid species using k-mer frequencies.

estimating genome size using k-mer frequencies, which plays a fundamental role in designing genome sequencing and analysis projects, has remained challenging for polyploid species, i.e., ploidy p > 2. To address this, we introduce findGSEP, which is designed based on iterative curve fitting of k-mer frequencies. Precisely, it firstly disentangles up to p normal distributions by analyzing k-mer frequencies in whole genome sequencing of the focal species. Secondly, it computes the sizes of genomic regions related to 1∼p (homologous) chromosome(s) using each respective curve fitting, from which it infers the full polyploid and average haploid genome size. findGSEP can handle any level of ploidy p, and infer more accurate genome size than other well-known tools, as shown by tests using simulated and real genomic sequencing data of various species including octoploids. findGSEP was implemented as a web server, which is freely available at http://146.56.237.198:3838/findGSEP/. Also, findGSEP was implemented as an R package for parallel processing of multiple samples. Source code and tutorial on its installation and usage is available at https://github.com/sperfu/findGSEP. Supplementary data are available at Bioinformatics online.

Structures of Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus virions reveal species-specific tegument and envelope features.

Discovered in 1964, Epstein-Barr virus (EBV) is the first identified human oncogenic virus and the founding member of the gammaherpesvirus subfamily. In 1994, another cancer-causing virus was discovered in lesions of AIDS patients and later named Kaposi's sarcoma-associated herpesvirus (KSHV), the second human gammaherpesvirus. Despite the historical importance of EBV and KSHV, technical difficulties with isolating large quantities of these viruses and the pleiomorphic nature of their envelope and tegument layers have limited structural characterization of their virions. In this study, we employed the latest technologies in cryogenic electron microscopy (cryoEM) and tomography (cryoET) supplemented with an artificial intelligence-powered data processing software package to reconstruct 3D structures of the EBV and KSHV virions. We uncovered unique properties of the envelope glycoproteins and tegument layers of both EBV and KSHV. Comparison of these features with their non-tumorigenic counterparts provides insights into their relevance during infection.

Evaluating the feasibility of upper arm ECG for cardiac monitoring

Abstract Background Ambulatory electrocardiogram (ECG) monitoring is essential for detecting paroxysmal cardiac events and tracking long-term physiological parameters. However, traditional Holter devices are cumbersome, restrict movement, and can cause skin irritation, resulting in sub-optimal patient compliance during extended monitoring periods. Wearable devices utilizing non-conventional form factors are emerging as promising non-intrusive alternatives for ECG monitoring. Purpose To determine the optimal location for single-lead ECG acquisition on the upper arm and assess the feasibility of using dry electrode armbands for cardiac monitoring when coupled with robust ECG processing software. Methods Stationary ECGs from 20 healthy adult participants were recorded across a two-phase data collection protocol and processed with clinically validated ECG software. In the first phase, the average signal amplitudes of wet-electrode ECGs obtained from 30 different configurations across the mid-brachial and proximal-brachial regions of the upper arm were assessed. In the second, the performance of two proprietary dry-electrode armbands, featuring either a single-point or three-point electrode strap, were evaluated on the optimal upper arm configuration using QRS detection and heart rate (HR) metrics. Comparative analysis was performed throughout using data simultaneously acquired on a gold standard Holter device in modified lead III (MLIII) configuration. Performance metrics were calculated relative to manually generated signal annotations. Results Wet-electrode-acquired ECGs from the proximal-brachial region exhibited significantly higher average signal amplitudes (0.12 ± 0.06 mV) compared to those from the mid-brachial region (0.05 ± 0.04 mV) of the upper arm (p < 0.05). The optimal configuration (A-F), positioned at the lateral and medial extents of the proximal-brachial region, demonstrated comparable average signal amplitudes (0.16 ± 0.07 mV, 0.16 ± 0.06 mV, 0.19 ± 0.08 mV) for single-point dry, three-point dry, and wet-electrode setups, respectively. Upon processing with ECG software, data from optimal dry-electrode configurations showed excellent average QRS sensitivity and specificity of 98.2% and 98.9% for the one-point strap, and 98.9% and 99.8% for the three-point strap, respectively. HR metrics from the optimized dry-electrode setups were comparable in accuracy to those derived from the reference Holter device, with the average HR error being similar across the three-point dry electrode strap (0.57% ± 0.28%), one-point dry electrode strap (1.16% ± 1.46%), and Holter device (0.74% ± 1.50%). Conclusion(s) Optimized upper arm single-lead ECG with dry electrodes can yield signals with sufficient amplitude and quality for automated ECG analysis. Coupled with robust ECG signal processing software, the cardiac metrics obtained from the optimized upper arm setups exhibited comparable performance to those derived from medical Holter data.

Serial changes in left and right ventricular global longitudinal strain in symptomatic obstructive hypertrophic cardiomyopathy treated with mavacamten: insights from VALOR-HCM trial

Abstract Background In severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM), the VALOR-HCM phase 3 randomized, double-blind, placebo-controlled clinical trial demonstrated that mavacamten, reduces the need for septal reduction therapy with sustained improvement in left ventricular outflow tract gradients and symptoms. As a cardiac myosin inhibitor, mavacamten’s mechanism of action reduces myocardial hypercontractility. Global longitudinal strain (GLS), a measure of regional myocardial function, is a more sensitive marker of systolic function and can complement left ventricular ejection fraction (LVEF). Objective We sought to assess serial changes in LV and right ventricular (RV)-GLS in patients enrolled in the VALOR-HCM study. Methods VALOR-HCM included 112 symptomatic obstructive HCM patients (mean 60 years, 51% male, LVEF 68%). Patients assigned to mavacamten at baseline continued the drug for 56 weeks (n=56) and those assigned to placebo crossed over to mavacamten (n=52) from week 16-56 (40-week exposure). LV and RV-GLS assessment was performed according to the current American and European guideline recommendations using a vendor-neutral post processing software. Non-foreshortened apical (4, 3 and 2-chamber) views were used to obtain peak value of LV-GLS. For RV-GLS, RV focused 4-chamber view was used to calculate RV 4-chamber and free wall strain. A more negative strain value is favorable. Results Serial changes in LVEF, average LV-GLS, and RV-GLS (4-chamber and free wall) from baseline to week 56 are shown in the Figure. Despite preserved LVEF at baseline, average baseline LV-GLS was abnormal. There were significant and continued improvements in LV-GLS in the total group from baseline to week 56. 12 patients had transient reduction in LVEF (<50%) requiring temporary drug interruption (permanent discontinuation in 3). The LV-GLS in this subgroup was worse at baseline compared to the total study population, with no significant worsening from baseline through week 56. In the overall population, excluding these 12 patients, LV-GLS demonstrated an improvement sustained through week 56. Both free wall and 4-chamber RV-GLS were abnormal at baseline and remained unchanged from baseline to week 56. Conclusions In the VALOR-HCM trial, despite hypercontractile LVEF at baseline, average baseline LV-GLS was worse than normal reference values. Treatment with mavacamten resulted in an improvement in LV-GLS from baseline through Week 56 (with no significant worsening of LV-GLS in the subgroup who experienced any reduction in LVEF <50%), suggesting a favorable long-term impact on regional LV systolic function due to the reduction of cardiac hypercontractility. Additionally, there was no significant detrimental impact on RV systolic function on serial GLS assessment.Serial changes in LV and RV GLS in VALOR

Serial changes in left atrial strain in symptomatic obstructive hypertrophic cardiomyopathy treated with mavacamten: insights from VALOR-HCM trial

Abstract Background In severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM), the VALOR-HCM phase 3 randomized, double-blind, placebo-controlled clinical trial demonstrated that mavacamten, a cardiac myosin inhibitor, reduces the eligibility for septal reduction therapy with sustained improvement in left ventricular (LV) outflow tract gradients and symptoms. Mavacamten also resulted in favorable cardiac remodeling, including improvement in left atrial volume index (LAVI), LV diastolic function, and biomarkers (NT-proBNP and troponin T). However, the impact of mavacamten on LA function is not known. Objective We sought to assess serial changes in LA strain measures in patients enrolled in the VALOR-HCM trial. Methods VALOR-HCM included 112 symptomatic obstructive HCM patients (mean age 60 years, 51% male). Patients assigned to mavacamten at baseline (n=56) continued therapy for 56 weeks and those assigned to placebo crossed over to mavacamten (n=52) from week 16-56 (40-week exposure). Echocardiographic LA strain assessment was performed according to the current American and European guideline recommendations, using a vendor-neutral post processing software. For assessment of LA strain components (reservoir, conduit, and contraction), the non-foreshortened apical 4-chamber view was utilized. The zero reference was set at end-diastole. Results Serial changes in LAVI and all components of mean LA strain from baseline to week 56 are shown in the Figure. At baseline, LAVI and all mean LA strain values were worse than reported normal mean thresholds. There was a continued and significant improvement in all 3 LA strain values, from baseline to week 56, along with a significant reduction in LAVI. Improvement in LAVI was seen earlier than improvements in LA strain. There was a significant inverse correlation between change in mean LAVI and LA reservoir strain from baseline to week 56 (r= -0.42, p<0.001). Conclusions In the VALOR-HCM trial, average LAVI and baseline LA strain values were significantly worse than reported normal thresholds. Treatment with mavacamten resulted in an improvement in LAVI and LA strain values from baseline through week 56 suggesting a sustained favorable impact on cardiac remodeling. The advantageous cardiac remodeling associated with long-term treatment with mavacamten may in turn have a favorable impact on the observed high burden of atrial tachyarrhythmias in HCM.Serial changes in LA strain in VALOR-HCM

Diabetes worsens the adverse association between myocardial diffuse fibrosis and left ventricular strain

Abstract Background Heart failure is a common cardiovascular complication to diabetes. Increased fibrosis of the myocardium has been suggested to be a mechanism, however, no convincing clinical evidence has so far been presented. A better understanding of how myocardial tissue characteristics influence functional aberration in diabetes could aid diagnosis, risk assessment and guide treatment. Native T1 is a CMR marker of diffuse fibrosis with diagnostic and prognostic value (1,2), and feature tracking (CMR-FT) strain is a sensitive measure of myocardial systolic function. In this study, we evaluated the association of CMR markers of fibrosis with markers of systolic function in individuals with and without diabetes. Purpose To understand the relationship between native T1 and myocardial strain and how diabetes may affect this. Methods Participants from the UK Biobank population imaging study were included. Left ventricular global longitudinal strain (GLS) was derived using a semi-automated batch processing software tool. Native T1 was derived from segmentation of the entire short axis slice using an automated quality control tool, excluding scans with predicted dice score of <0.7. Multivariable linear models were used with the strain metrics as the outcome variable and native T1 and diabetes as the exposure variables. These models were adjusted for age, sex, BMI, ethnicity, smoking and alcohol status, prevalent hypertension hypercholesterolaemia and coronary artery disease. The effect of interaction between diabetes and native T1 on GLS was examined by introducing an interaction term. Results In total 41,533 participants were included, of which 1957 had diabetes – see Table 1 for baseline characteristics. The average GLS measured for those with diabetes was -17% and was -18% for those without. The average native T1 in those with diabetes was 935ms and 933ms for those without on the background of greater prevalence of cardiovascular risk factors in those with diabetes. In model adjusted for all relevant co-variates, individuals with diabetes had worse GLS measured compared to those without diabetes (β-coefficient: 0.51, p value <0.001). Increasing fibrosis (native T1) was associated with worsening GLS (β-coefficient: 0.005, p value <0.001) in all participants. However, in those with diabetes, increasing native T1 was associated with a greater decline in GLS compared to those without diabetes (interaction term β-coefficient: 0.005, p value <0.001), with a relative impairment seen within normal ranges for native T1 - see Figure 1. Conclusion(s) This is the largest study of its kind to demonstrate a dose dependent relationship between increasing native T1, representing potential myocardial fibrosis, and myocardial strain, representing cardiac dysfunction. Our findings indicate that increased fibrosis alone does not explain the higher risk of HF in diabetes, other mechanisms, perhaps intracellular, might be at play.

A new free radical scavenger, resorcimoline, prevents ischaemia/reperfusion injury in the heart

Abstract Introduction Ischaemic heart disease remains the leading cause of death worldwide. Early coronary revascularisation is the most important treatment. Recent findings have revealed that reactive oxygen species (ROS) can lead to tissue damage following coronary artery revascularisation, known as ischaemia-reperfusion injury. In this study, we focused on resorcimoline, a new free radical scavenger that was generated during the synthesis of dimethylresveratrol and dimethylpiceatannol. Last year, we reported the scavenging activity in vitro against multiple ROS, confirmed by the electron spin resonance spectrometry (Ref. 1). Purpose This study aimed to assess the potential of resorcimoline as a novel therapeutic treatment for reducing the degree of infarction caused by myocardial ischaemia, by eliminating ROS generated during myocardial ischaemia-reperfusion. Methods Nine-to-eleven-week-old male Wistar rats were subjected to acute myocardial ischaemia induced by ligation of the left anterior descending coronary artery for 30 minutes, followed by reperfusion for 24 hours. Rats received intravenous injections of resorcimoline at 6 mg/kg before coronary ligation or saline as a control (n = 9 vs. n = 8). The heart sections were double-stained with Evans blue 1% and triphenyltetrazolium chloride 1% to assess infarct area and area-at-risk. For immunohistochemical study, the other ischaemia/reperfusion models were treated with resorcimoline and saline (n = 7 vs. n = 7) as above, and the middle parts of the hearts were embedded in optimal cutting temperature compound and quickly frozen. In the H＆E-stained section, the infarct border zone was defined as a 2-mm band surrounding the necrosis area. Troponin I levels in serum were measured using ELISA. Primary cultured cardiomyocytes were treated with 10 μM angiotensin II for 3.5 hours and then exposed to resorcimoline for 30 minutes at an increasing dosage. A cellular ROS assay kit was used to assess the levels of ROS in the cardiomyocytes and the number of cells was counted with DAPI stain using an image processing software. Results Infarct size in resorcimoline-treated animals was significantly smaller than in control animals (41.8±19.4% vs. 60.8±12.9%, p=0.03, Fig. 1A) and area-at-risk was not significantly different (58.0±27.8% vs. 51.9±18.5%, p=0.61). Apoptotic cells in the border zone were significantly reduced in resorcimoline-treated animals (32.0±11.7% vs. 55.1±16.9%, p=0.01, Fig. 1B). Troponin I levels in resorcimoline-treated animals were significantly lower than in control animals (4524±3596 vs. 7856±4653, p=0.04, Fig. 1C). resorcimoline significantly reduced angiotensin II-induced ROS in cardiomyocytes in a concentration-dependent manner (Fig. 2A,B). Conclusion This novel compound, resorcimoline, can reduce infarct size induced by coronary ischaemia-reperfusion injury by reducing the ROS damage to myocardiocytes in the border zone and cellular ROS levels in cardiomyocytes.

ScatterX： A software for fast processing of high-throughput small-angle scattering data

Abstract Scattering experiments become increasingly popular in modern scientific research, including the areas of materials, biology, chemistry, physics, etc. Besides, various types of scattering facilities have been developed recently, such as lab-based X-ray scattering equipment, national synchrotron facilities and large neutron facilities. These above-mentioned trends bring up fast-increasing data amounts of scattering data, as well as different scattering types (X-ray, neutron, laser and even microwaves). This struggles with data analysis software of the last generation, where data are usually analyzed assuming certain first-principle models and given data formats. To help researchers process and analyze scattering data more efficiently, we developed a general and model-free scattering data analysis software based on matrix operation, which has the unique advantage of high throughput scattering data processing, analysis and visualization. To maximize generality and efficiency, data processing is performed based on a three-dimensional matrix, where scattering curves are saved as matrices or vectors, rather than the traditional definition of paired values. It can not only realize image batch processing, background subtraction and correction, but also analyze data according to scattering theory and model, such as radius of gyration, fractal dimension and other physical quantities. In the aspect of visualization, the software allows the modify the color maps of two-dimensional scattering images and the gradual color variation of one-dimensional curves to suit efficient data communications. In all, this new software can work as a standalone platform for researchers to process, analyze and visualize scattering data from different research facilities without considering different file types or formats. All codes in this manuscript are open-sourced and can be easily implemented in matrix-based software, such as MATLAB, Python and Igor.

An Ultrawide Bandwidth Digital Backend System Based on PFB Algorithm for QTT

For the planning of the QiTai radio Telescope ultrawide bandwidth low-frequency pulsar receiving system, we designed and implemented a Field-Programmable Gate Array (FPGA)+CPU/GPU hybrid architecture digital backend system based on the Polyphase FilterBank (PFB) channeling algorithm. We used the FPGA signal acquisition and processing platform to implement ultrawide bandwidth signal sampling and designed the PFB algorithm to realize the digital channelization of multiple analog bandwidth signals. We also developed data encapsulation and multichannel parallel distribution firmware algorithms and realized the real-time parallel transmission of high-speed astronomical data streams based on the VLBI Data Interchange Format. We developed the Ultra Wide bandwidth Low-frequency pulsar data process PIPEline, which realized the real-time processing and data packaging of massive pulsar signals. Using the L-band (964–1732 MHz bandwidth) receiving system of the Nanshan 26 m radio telescope, we conducted a systematic test on the designed digital backend system and obtained high-quality observation data. By using the professional pulsar data processing software DSPSR to process the observation data, we obtained high signal-to-noise ratio pulse profiles.

An ecosystem of interconnected technologies to increase efficiencies in blood establishments: The example of the Blood and Tissue Bank of Aragón, Spain.

Blood establishments face environmental, financial, demographic and societal challenges that may impair sustainable blood supply to patients. This study presents the technologies (devices and software) assembled in a global ecosystem implemented by the Blood and Tissue Bank of Aragón (BTBA), Spain, over the last decade to overcome these challenges. Descriptive yearly activity data (2013-2023) of BTBA were retrospectively collected to evaluate the impact of different technologies on blood processing efficiency, focusing on the production of blood components (red blood cell concentrates [RCCs], platelet concentrates [PCs]) and plasma. Operator satisfaction about the technologies introduced in daily routine work was also monitored. Between 2013 and 2023, the annual production decreased by 16.0% for RCCs and increased by 13.3% for PCs. From 2020, all PCs were treated with pathogen reduction technology, and no inventory stock-out was reported. The lowest PC expiry rate (0.2%) was observed after the implementation of the software for blood processing and PC stock management. The deployment of this software also improved plasma recovery: on average, an extra plasma volume of 9 mL was collected per donation in 2023 compared to 2015. A survey confirmed staff satisfaction. The progressive implementation of automated and software-based solutions was key to increasing efficiencies in BTBA. This enabled the optimization of blood processing by maximizing productivity, enhancing traceability, reducing overproduction and wastage and increasing the yield of recovered plasma, while ensuring blood product safety and staff satisfaction.

Competencies of Using Computers in Teaching: An Evaluative Study on Students of the Faculty of Education, Sohag University

This study aimed to assess the competencies of Sohag University’s Faculty of Education students in computer-based teaching competencies, employing a descriptive-analytical approach and a questionnaire covering eight core areas: the role of computers in education, information technology skills, integration of computers in teaching, use of the internet and email for instruction, operation of Windows OS, utilization of presentation software, spreadsheets, and word processing tools. A cognitive achievement test was also developed to measure students’ knowledge in these areas, with a sample comprising 235 students from both scientific and literary disciplines. The findings revealed varied student perceptions regarding the impact of their academic studies on developing computer-based teaching skills, with statistically significant differences (p ≤ 0.01) favoring scientific students over literary students in both their questionnaire responses and test performance. Additionally, students generally exhibited low competency scores on the test, highlighting the need for enhanced focus on practical skill development. A positive correlation (r = 0.26) was also identified between literary students' questionnaire responses and their test performance, statistically significant at the 0.01 level, underscoring the importance of bridging the gap between theoretical knowledge and practical application.

7-axis synchronization-integrated on-the-fly laser texturing system of freeform surface: Design and development

Abstract While laser surface texturing (LST) is a promising manufacturing technique for surface functionalization, simultaneously realizing high precision and high efficiency in the LST of complex curved surface is challenging, due to continuously varied geometries of laser-matter incidence. In the present work, we propose a novel manufacturing system of 7-axis on-the-fly LST for complex curved surface, based on the integrated synchronization of 5-axis linkage motion platform with 2-axis galvanometer. Specifically, the algorithm for decomposing spatial texture trajectory on curved surface into low-frequency and high-frequency parts is established, based on which the kinematic model of synchronized 7-axis system is developed to derive the motion of each axis in both 5-axis linkage motion platform and 2-axis galvanometer simultaneously. Subsequently, the synchronized 7-axis LST system is experimentally realized, including the setup of mechanical stages integrated with optical path, the configuration of numerical control unit, and the development of processing software. Finally, case study of 7-axis on-the-fly LST of freeform aluminum surface is performed, and the advantages in terms of processing efficiency and texturing accuracy over 5-axis linkage LST are demonstrated. The correlation of reduced following errors between mechanical stages with the promoted performance of curved surface texturing by the 7-axis on-the-fly LST is further analyzed. Current work provides a feasible solution for establishing the manufacturing system for high performance LST of complex curved surface.

A Database-based Automatic Cartography Method

Abstract. At present, GIS data, which contains a large amount of semantic information, has become the main data source for map cartography. In this paper, based on the existing multi-scale database, we study a database-based automatic cartography method to meet the needs of multi-scale map cartography, and replace the traditional process by the intelligent processing of software to shorten the cycle of cartography, improve the productivity of map cartography, and at the same time, reduce the error rate caused by manual work, and improve the overall quality of map production.

Assessment of natural and anthropogenic impacts of the Irganay Hydroelectric Power Station reservoir zone on eco‐ and geosystems using remote sensing data, Dagestan, Russia

Aim. The research and mapping of natural object dynamics using aerial and satellite imagery is one of the long‐established and actively developing fields of remote sensing and geographic research. The current phase is characterised by the wide availability of remote sensing data processing software, which offers almost unlimited possibilities for transforming and integrating datasets from different periods.Material and Methods. For the effective use of archival maps in studying territorial dynamics, two interconnected factors are critical: the date of the map’s creation and the positional accuracy of the mapped objects. The materials used in this study were TM/Landsat satellite images from the periods 2002–2017 and 2006–2014.Results. Reservoirs with a surface area of up to 60–70 km² and a volume of up to 250 million m³ increase absolute air humidity by 10–15 %. In areas with a hot climate, the impact of a reservoir on air humidity is even more pronounced.Conclusions. The anticipated significant changes in the microclimate are expected to affect the structure of agricultural production in the Irganay valley and in the villages of Maidanskoye, Untsukul, and Gimry, particularly through changes in precipitation distribution during the growing season.

Gcxgclab: An R Package for Two-Dimensional Gas Chromatography Preprocessing and Analysis.

Comprehensive two-dimensional gas chromatography (GC×GC) is an established technique capable of chromatographically separating thousands of analytes in complex matrices. When coupled with highly sensitive detectors such as a high-resolution mass spectrometer, these instruments produce large multidimensional data sets. A prevailing challenge for GC×GC users is efficient data handling and analysis. Although commercial software packages exist for GC×GC data analysis, these platforms are typically optimized for low-throughput qualitative data interpretation utilizing desktop computer systems. Additionally, commercial GC×GC data processing packages offer little flexibility to explore custom or novel data processing concepts. In this work, an open-source R package, called "gcxgclab", was developed as an alternative data processing package for GC×GC users and offers data preprocessing and analysis functions including baseline correction, smoothing, phase shift, peak detection, peak alignment, extracted ion chromatogram, mass spectra extraction, mass defect analysis, and targeted and nontargeted analysis. This package was designed to be customizable and allows for batch data processing on desktops or high-performance computing systems to increase the throughput. gcxgclab is available for free on the Comprehensive R Archive Network (CRAN) at https://cran.r-project.org/web/packages/gcxgclab/index.html.

Enhancing mechanical properties of 2024-Aluminium Alloy Matrix Composite strengthened by Y2O3 ceramic particles

The development of high-strength, low-weight composite materials has been a high-priority demand in the structural, aerospace, automotive, renewable energy, and sports equipment sectors. Micro-particle size Yttrium oxide (Y2O3) has been utilized to enhance the microstructure and mechanical characteristics of the 2024-Al alloy. The stir-casting technique is employed to prepare 2024-Al alloy and aluminum matrix composites (AMCs) with different Y2O3 weight fractions (1 %, 2 %, and 3 %). Scanning electron microscope ESM with EDS analysis and optical microscope imaging have been used to assess the development in the microstructure of AMCs. Furthermore, optical microscope images have been analyzed by using image processing software, ImageJ to evaluate development in microstructure grain size. Vickers' micro-hardness, tensile strength, elongation, and wear-resistant tests were conducted to assess the mechanical properties of AMCs. AMC image analysis results demonstrated a significant reduction in microstructure grain size. The highest reduction in grain size was recorded when adding 2 wt. % of Y2O3, which was approximately 22.5 % smaller than that of the plain alloy. Other mechanical test results demonstrated an increase in the hardness and tensile strength of AMCs compared with the plain alloy by approximately 58 % and 116 %, respectively, upon the addition of 2 wt. % of Y2O3, also tensile test shows increasing of AMCs elongation at failure point with increasing Y2O3 content, 132 % upon adding 3 wt. %. Finally, wear tests show a decrease in the AMC wear rate with an increasing Y2O3 weight fraction compared to the plain alloy.

Sentiment analysis of letters of recommendation for a U.S. pain medicine fellowship from 2020 to 2023.

Letters of recommendation (LORs) are an important part of pain medicine fellowship applications that may be subject to implicit bias by the letter's author. This study evaluated letters of recommendation for applications to pain medicine fellowships in the United States to characterize biases and differences among applicants over four application cycles. This was a retrospective single-site cohort study. De-identified LORs were collected from 2020 to 2023 from one institution. The Valence Aware Dictionary and sEntiment Reasoner (VADER) natural language processing package scored positive LOR sentiment. In addition, the deep learning tool, Empath, scored LORs for 15 sentiments. Wilcoxon rank-sum and one-way ANOVA tests compared scores between applicant demographics: gender, race, medical school type, residency specialty, and chief resident status, as well as letter writers' academic position. Nine hundred and sixty-four applications were studied over four application cycles. Program directors wrote fewer words (p = 0.020) and less positively (p < 0.001) compared to department chairs and letter writers with neither position. Department chairs wrote with less "negative emotion" compared to both program directors and writers with neither position (p < 0.001). Anesthesiologist applicants received more letters highlighting "achievement" (p < 0.001) while PM&R applicants submitted letters with less "negative emotion" (p < 0.001) compared to other specialties. Chief residents' letters scored higher in "leader" sentiment (p < 0.001) and lower in "negative emotion" (p < 0.001). Linguistic content did not favor certain genders or races over others. However, disparities in LORs do exist depending on an applicant's specialty and chief resident status, as well as the academic status of the letter writer.

Sample size for assessing a diagnostic accuracy of AI-based software in radiology

Introduction. Determining the minimum sample size for solving various tasks is an extremely important and at the same time unexplored problem. There are many methods, but most of them are not applicable for AI-based software validation.Aim: To consider a methodology for determining a balance of classes “norm”/ “abnormality” and propose a statistical approach to determine the data amount necessary for testing AI-based software (validation).Material and Methods. The results of AI-based software were analyzed using dataset of mammograms. Mammograms were classified by the presence of breast cancer (“abnormality”) and the absence of breast cancer (“norm”). The general set contains 123,301 unique studies. The original balance of classes in the study was “norm” 89.3%/“abnormality” 10.7%. As the results of AI-based software (ML-algorithm), a probability of the presence of pathology in the entire study was taken. The following values were used as empirical data (GT): 0 – in case of Bi-RADS classes 1 or 2 diagnosed by a doctor, and 1 – in case of Bi-RADS classes 3, 4, 5. Each data sample is transferred to AI-based software for processing. Quality metrics are calculated based on its results: AUC ROC. All the described actions were repeated 10,000 times for all the studied balances of “norm”/”abnormality”. Based on the results of AUC ROC calculations, mean values were calculated for different random data series with the same balances. Mean AUC ROC values were subjected to analysis.Results. A maximum value of the coefficient of variation of AUC ROC values for 10% “abnormality” share is achieved at the number of studies equal to 190; for the 20% share, it is 80 studies; for the 30% share – 120 studies, for the 40% share – 110 studies, and for the 50% share – 70 studies.Conclusion. Summarizing the conducted study results, it can be concluded that when testing AI-based software, it is necessary to consider that the number of studies reflecting the greatest heterogeneity of AUC ROC values (the largest deviation from the mean value) is different for various class balances. If the purpose of validation is to establish the worst-case behavior of AUC ROC values, then for the studied AI-based software, the “abnormality” share should be 10%, and the number of studies 190. If the validation is carried out under conditions of a limited amount of data, then the “abnormality” share should be 50% and the number of studies equal to 70.

Thermal testing of corundum ceramics: pulse heating and optimized data processing algorithms

A review of the types of defects in the production of corundum ceramic tiles and traditional methods of integrity testing of products made of this material is carried out. The integrity of tiles containing artificial defects was investigated by the method of active thermal testing using pulsed optical heating. A scheme of two-way thermal testing with software processing of the initial thermograms using the Parker method is applied. It has been established that the best results in detecting internal defects in ceramic tiles with a thickness of 10 mm during thermal stimulation using xenon lamps are obtained by the method of two-way thermal testing with the construction of thermal conductivity maps.

Comprehensive Dynamic 3-Dimensional Analysis of Tricuspid Valve in Functional Tricuspid Regurgitation: Implications for Prophylactic Tricuspid Valve Intervention

ObjectivesUnderstanding of changes in tricuspid annulus (TA) during secondary or functional tricuspid regurgitation (TR) is currently limited and its surgical management relies on limited 2-dimensional (2D) imaging. The aims of the study were to: 1) track and measure changes in TA using 3-dimensional (3D) echocardiography during complete cardiac cycle in patients with functional TR when compared to no TR, and 2) compare TAPSE derived from 2D and 3D coordinates as a measure of RV function when compared to standard method of fractional area change (FAC). DesignIntraoperative 3D echocardiography data was collected prospectively followed by post processing software analysis to track and reconstruct changes throughout the cardiac cycle. SettingData was collected from 108 patients undergoing left sided heart surgery at two large academic centers – Beth Israel Deaconess Medical Center in Boston, MA and Rhode Island Hospital, Providence, RI between from November 2018 to April 2020. ParticipantsFinal dataset (n=92) included two groups: no significant functional tricuspid regurgitation (NTR) group (n=74), defined as ≤ mild tricuspid regurgitation (TR) and TA < 35 mm, and a significant functional TR (FTR) group (n=18), defined as ≥ moderate TR. Interventions3D TEE datasets were analyzed, and the motion of TA coordinates was tracked during complete cardiac cycle in 2D and 3D planes using post-processing and software analysis. Computational modeling of TA motion was performed using computer-aided design. In further analysis, reconstructed and 3D printed models of TV were developed for the two groups. Measurements and Main ResultsPatients in FTR group had larger TA size during the cardiac cycle with less overall excursion and reduced annular dynamism. 3D motion of TA for lateral (L), anterolateral (AL) and posterolateral (PL) coordinates was lower in FTR group compared to NTR group [(18±6.8 vs 13.6±8.5, p=0.02), (15.2±5.5 vs 11.3±6.0, p=0.009) and (17.6±6.6 vs 12.3±5.2, p=0.002) respectively]. TAPSE derived from 3D planes was more accurate for RV function assessment (AUC 0.704, p = 0.011) than 2D TAPSE (AUC 0.625, p = 0.129). Finally, in the FTR group, the anteroseptal-posterolateral (AS-PL) diameter was consistently larger during all phases of cardiac cycle, in comparison with septo-lateral (S-L) diameter. Conclusion3D echocardiographic assessment of TA helps better understand its geometry and dynamism in functional TR, and is more accurate than 2D measurements for RV function assessment.