Search Results (646)

Leaf area is a critical trait in plant physiology and agronomy, yet conventional measurement approaches such as those using ImageJ remain labor-intensive, user-dependent, and difficult to scale for high-throughput phenotyping. To address these limitations, we developed a fully automated, open-source Python tool for quantifying citrus leaf area from scanned images using multi-mask HSV segmentation, contour-hierarchy filtering, and batch calibration. The tool was validated against ImageJ across 11 citrus cultivars (n = 412 leaves), representing a broad range of leaf sizes and morphologies. Agreement between methods was near perfect, with correlation coefficients exceeding 0.997, mean bias within ±0.14 cm², and error rates below 2.5%. Bland–Altman analysis confirmed narrow limits of agreement (±0.3 cm²) while scatter plots showed robust performance across both small and large leaves. Importantly, the Python tool successfully handled challenging imaging conditions, including low-contrast leaves and edge-aligned specimens, where ImageJ required manual intervention. Processing efficiency was markedly improved, with the full dataset analyzed in 7 s compared with over 3 h using ImageJ, representing a >1600-fold speed increase. By eliminating manual thresholding and reducing user variability, this tool provides a reliable, efficient, and accessible framework for high-throughput leaf area quantification, advancing reproducibility and scalability in digital phenotyping. Full article

Background/Objectives: Frailty is increasingly recognised as an important contributor to outcomes following cardiac surgery. There are various measures of frailty described, but many include subjective assessments impacting reliability and reproducibility of measurement. A potential biomarker: advanced glycation end products (AGEs) have been suggested to closely correlate with frailty. This may offer the opportunity to objectively measure frailty and have potential use in preoperative risk assessment. The objective and aim of this narrative review is to assess the association between AGEs and outcomes following surgery, in order to evaluate the use of AGEs for preoperative risk assessment. Methods: This review involved searching five databases including the following: MEDLINE (through Ovid), Embase, Cochrane, ClinicalTrials.gov, and a specified Google Scholar search for studies published between database inception and 20 February 2025. The 1142 identified articles were then subjected to various inclusion and exclusion criteria. This exclusion criteria included all articles that were not in the English language, studies involving patients under 18 years of age, and studies that were incomplete or for whom the data was not yet available. This left 11 articles for which a ‘related articles’ search was performed on Google Scholar on 6 March 2025, as per the PRISMA-S extension guidelines, to obtain all relevant articles available. In the end, data analysis was conducted on 13 articles with a total of 2402 participants. These were categorised by type of surgery before analysis was performed for each surgical category. The quality of evidence was assessed using ROBINS-I tool and a risk of bias table has been provided. This study was provided no external sources of funding. Results: Four out of the five studies in cardiac surgery showed a statistically significant association between AGE levels and post-operative complications and outcomes. This association was also seen across thoracic and general surgery. Association was demonstrated with various post-operative complications as well as mortality. These relationships are supported by various pathophysiological mechanisms, including the ability of AGEs to induce oxidative stress, activate inflammatory mediators, and cause endothelial dysfunction. Conclusions: There is a body of evidence supporting the association between AGEs level and cardiac surgical outcomes. This objective measure of frailty could have significant utility in preoperative risk assessment and offer the opportunity to identify patients who will benefit from undergoing prehabilitation. Full article

Human mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMG-CoA synthase, mHS) synthase is a key enzyme in ketogenesis and is located mainly in the liver, but also in the colon, skeletal muscle, heart, pancreas, and testes. It is an inner mitochondrial membrane-associated protein. Mutations in the HMGCS2 gene, which encodes this enzyme, lead to “mHS deficiency,” a rare, autosomal recessive, inherited metabolic disorder. To date, about 100 patients with this disorder have been described. The disorder usually appears during the first year of life, often after a period of starvation or an intercurrent illness. A total of 77 different DNA mutations has been described that are considered responsible for mHS deficiency, although the mechanisms leading to loss of function are not fully understood. To study how the different missense variants affect the enzymatic activity of the protein on an atomic scale, we used molecular dynamics computational simulation techniques for variants whose activity could be measured “in vitro.” The study included a total of 46 molecular dynamics trajectories of enzyme–substrate/product interaction simulations, each 500 ns long (23 microseconds total). Currently, the atomic and biophysical effects of the mHS variants on their catalyzed reactions have not been studied in detail experimentally. To our knowledge, molecular dynamics simulations are one of the most promising tools for understanding the molecular basis of the phenotypic consequences of these variants. In the present work, molecular dynamics simulations reliably reproduce most experimental enzyme activity measurements, supporting their future application to the study of new mHS mutations. Full article

Accurate assessment of protein content in Foods for Special Medical Purposes (FSMPs) is critical for patients with chronic kidney disease, who require tightly regulated protein intake. This study aimed to develop and apply a rapid, low-volume, and reproducible microchip-based gel electrophoresis method for analyzing total nitrogen (TN) content and electrophoretic profiles in FSMPs. Products of different consistencies (powder, liquid, yoghurt-like) were tested to evaluate the influence of common additives (e.g., milk proteins, stabilizers, sweeteners) on TN levels and protein patterns. The results revealed considerable variation in fractions among brands, largely attributable to additive composition. Notably, TN levels often exceeded the declared protein content, potentially leading to unintended nitrogen overconsumption in clinical settings. Statistical analysis identified significant TN differences between infant and adult FSMPs in liquid formulations, while powdered forms showed no such distinction. These findings highlight the clinical importance of precise analytical monitoring, as discrepancies between measured TN and labeled protein content could compromise dietary management in vulnerable populations. The proposed method provides a reliable tool for FSMP quality control and supports safer nutritional planning in therapeutic diets. Full article

The HYPEX^® process is a novel method for conditioning spent ion exchange resins from nuclear power plants, aiming to reduce final waste volume and carbon emissions by stabilizing the resins in metakaolin-based geopolymers. This study addresses the challenge posed by the natural variability of commercial metakaolin and defines a testing strategy to ensure consistent performance of the final matrix. The reactivity of two batches of metakaolin, characterized by comparable chemical composition and BET surface area, was evaluated by monitoring temperature evolution during geopolymerization at varying water-to-solid ratios. The resulting geopolymers were tested for compressive strength, water permeability, and strontium leachability to assess correlations between precursor properties and final matrix performance. Despite similar compositions, the two batches showed marked differences in compressive strength that could be linked to early thermal behavior. These findings demonstrate that conventional precursor characterization is insufficient to guarantee reproducibility and that thermal profiling is useful to predict mechanical performance. The results suggest the implementation of thermal response monitoring as a quality control tool to ensure the reliability of geopolymer wasteforms in nuclear applications. A simplified analytical model for the thermal evolution during geopolymerization was also developed, matching qualitatively the measured evolution, to suggest scale-up rules from laboratory specimens to full-scale drums, which should be achieved while preserving the thermal evolution. Full article

Background: Left atrial strain, particularly reservoir strain, has emerged as a sensitive marker of left atrial function and an early indicator of diastolic dysfunction and cardiovascular risk. However, automated left atrial strain analysis is not universally available, particularly in resource-limited settings. In this study, we propose a manual method for calculating biplane left atrial reservoir strain and validate its agreement with automated software in patients with atrial fibrillation and in sinus rhythm. Methods: Echocardiography examinations from 30 patients with atrial fibrillation and 30 patients in sinus rhythm were analyzed. Left atrial reservoir strain was calculated using both an automatic speckle tracking imaging-based algorithm and a manual point-by-point method based on atrial wall delineation. Agreement between methods was assessed using Pearson correlation, Bland–Altman analysis, and intraclass correlation coefficient. Results: Strong correlation and excellent agreement were observed between the two methods in both groups. Pearson correlation coefficients were r = 0.95 (p < 0.0001) in the atrial fibrillation group and r = 0.94 (p < 0.0001) in the sinus rhythm group. Bland–Altman analysis showed narrow limits of agreement, particularly in the atrial fibrillation group. The intraclass correlation coefficient was 0.95 in atrial fibrillation and 0.92 in sinus rhythm, indicating excellent reliability. The standard error of measurement and minimal detectable change were low in both groups. Conclusions: Manual measurement of left atrial reservoir strain is feasible, reproducible, and demonstrates excellent agreement with automated software. It may serve as a reliable alternative in clinical scenarios where automated tools are unavailable. Full article

This study was designed to investigate the variability of renal ultrasound measurements, focusing on the impact of physician experience and patient position. Background: Since decreased kidney length is considered an indicator for chronic renal disease, understanding measurement repeatability and reproducibility is crucial for establishing effective diagnostic guidelines. Methods: Fifty healthy young adults underwent renal ultrasound scans performed by three examiners with varying levels of experience (12 years, 5 years, and 4 weeks). Renal length was measured at the level of the hilum in three patient positions: supine, lateral decubitus, and prone, using a 2–6 MHz convex probe (GE Logiq S8). Results: This study found that examiner experience significantly affected the results of sonographic measurements. However, the Interclass Correlation Coefficient analysis for all examiners demonstrated good reliability in most positions, with the highest values observed for the prone position. Measurements in the lateral decubitus position showed highest values, especially for the most experience examiner. The less experienced sonographers produced more variable results. Conclusions: Standardized patient positioning improves the accuracy and reproducibility of renal ultrasound measurements. The prone position offers a balance of reliability and practicality, especially for less experienced operators. Full article

Background/Objectives: Spinal diffusion tensor imaging (sDTI) remains a challenging method for the selective evaluation of key anatomical structures, like pyramidal tracts (PTs) and dorsal columns (DCs), and for reliably quantifying diffusion metrics such as fractional anisotropy (FA), radial diffusivity (RD), mean diffusivity (MD), and axial diffusivity (AD). This prospective, single-center study aimed to assess the reproducibility, robustness, and reliability of an optimized axial sDTI protocol, specifically intended for long fiber tracts. Methods: We developed an optimized Stejskal–Tanner sequence for high-resolution, axial sDTI of the cervical spinal cord at 3.0 T. Using advanced standardized evaluation and post-processing methods, we estimated DTI values for PTs, DCs, and AHs at the level of the second cervical vertebra. Reliability was evaluated through repeated measurements in 16 healthy volunteers and by comparing results from two 3.0 T scanners (Magnetom Skyra and Magnetom Prisma, Siemens Healthineers, Erlangen, Germany). Reproducibility was assessed using paired t-tests, intraclass correlation coefficients (ICCs), Bland–Altman analysis, and coefficients of variation (CVs). Results: The optimized sDTI protocol demonstrated high consistency for FA between test–retest sessions and across scanners. For the Skyra, the DC region showed the highest reliability (average ICC = 0.858) followed by the PT region (average ICC = 0.789). On the Prisma, the PT region reached an average ICC of 0.854, with the DC region at 0.758. Pooled inter-scanner data indicated good-to-excellent agreement, particularly in the PT region (average ICC = 0.860). FA CVs remained low (<10%) across all regions and scanners. RD showed good-to-excellent ICC values for PTs and DCs (average ICC for Skyra 0.642 and 0.769 and 0.926 and 0.830 for Prisma, respectively) but showed a higher CV between 14.6 and 19.4% for these two scanners. Conclusions: Improved sDTI offers highly reproducible FA measurements for all metrics with scanner independence, supporting its potential as a robust tool for detecting and monitoring spinal cord pathologies. Full article

This study presents a two-dimensional (2D) hydro-morphodynamic simulation of sediment dynamics in the Gemenc floodplain, a critical ecological zone along Hungary’s Danube River. The 60 km study area has a mean discharge of approximately 2300 m³/s, with peak floods exceeding 8000 m³/s. The objective was to analyze sediment transport, deposition, and flood hydrodynamics to support future floodplain restoration. The HEC-RAS 2D model was calibrated using water levels (Baja station), 2024 flood discharges, suspended sediment measurements, and visual stratigraphy surveys conducted after the event. A roughness sensitivity analysis was conducted to optimize Manning’s n values for various land covers. The hydrodynamic model showed strong agreement with observed hydrographs and discharge distributions across multiple cross-sections, capturing complex bidirectional flow between the main River and side branches. Sediment dynamics during the September 2024 Danube flood were effectively simulated, with SSC calibration showing a decreasing concentration trend, highlighting the floodplain’s function as a sediment trap. Predicted deposition patterns aligned with field-based visual stratigraphy, confirming high sediment accumulation near riverbanks and reduced deposition in distal zones. The model reproduced deposition thickness with acceptable variation, demonstrating spatial reliability and predictive strength. This study underscores the value of 2D modeling for integrating hydrodynamics and sediment transport to inform sustainable floodplain rehabilitation. Full article

Objectives: Strain elastography (SE) is a non-invasive ultrasound-based technique for evaluating tissue elasticity. This study investigated whether SE can reproducibly detect differences in suburethral tissue stiffness between women with stress urinary incontinence (SUI) and continent controls. Methods: In this prospective cohort study, 40 women (20 with SUI, 20 continent controls) underwent introital two-dimensional (2D) ultrasound in the midsagittal plane at rest. SE was performed at three predefined suburethral regions of interest (ROIs): the internal urethral orifice (IUO), midurethra (MU), and external urethral orifice (EUO), with the adipose layer (AL) serving as reference tissue. Group comparisons and reproducibility analyses were conducted. Results: SE enabled reliable in vivo assessment of suburethral elasticity. Women with SUI demonstrated significantly higher tissue elasticity at all three urethral levels compared to controls. The MU level showed the highest diagnostic accuracy (AUC = 0.813; sensitivity = 0.65; specificity = 0.85). Measurement reproducibility was excellent, with intraclass correlation coefficients exceeding 0.95 across all ROIs. Conclusions: SE is a feasible, reproducible imaging modality for assessing suburethral biomechanics in women with SUI. It effectively distinguishes affected individuals from continent controls, particularly at the midurethral level. Standardized protocols and diagnostic thresholds are needed to facilitate clinical integration of SE in the evaluation and management of SUI. Full article

Objective: This study aimed to investigate whether the subjective assessments of strong and weak muscles in the Functional Myodiagnosis muscle test (FMD-MT) can be objectively and reproducibly verified using physically measurable parameters. Additionally, we sought to evaluate the reliability of the manual muscle test in order to reinforce the scientific evidence supporting this accepted, yet not widely adopted, complementary medicine method. Methods: In a crossover observational study, three experienced medical practitioners conducted the FMD-MT of the rectus femoris muscle on 24 healthy participants using a specially designed therapy bench, with all measurements recorded via an oscillogram. The study investigated the force–time integral, joint angle change, additional force load, mean force turning point 1, as well as the interrater reliability and validity of both examiner assessments and instrumental analyses for the two muscle reaction variants: strong and weak. Results: A significant difference between the response pattern of strong and weak muscles was identified for the force–time integral (p = 0.005), the change in joint angle (p < 0.001), and the additional force load (p = 0.001). No difference between strong and weak muscles could be detected regarding the force turning point 1 (p = 0.972). The examiners demonstrated 100% accuracy in identifying weak muscle reactions as weak, and 99.2% accuracy in identifying strong muscle reactions as strong (p = 0.316). The overall intra-class correlation coefficient was 0.984. The oscillogram correctly visualized weak muscle reactions in weak muscles with an accuracy of 81.7%, and strong muscle reactions in strong muscles with an accuracy of 86.7% (p = 0.289). Conclusions: The Functional Myodiagnosis muscle test (FMD-MT) enables a clear and objective differentiation between strong and weak muscles, with statistically significant differences observed in the force–time integral, additional force load, and joint angle changes. Under rigorously standardized testing conditions, the FMD-MT of the rectus femoris muscle demonstrates a validity rate of 99.6% and an excellent reliability (ICC 0.984). Consequently, the FMD muscle test proves to be a reliable, reproducible, and objective diagnostic method. Trial registration: German Register of Clinical Studies U1111-1212-6622. Full article

Four-dimensional (4D) flow MRI has shown promise for the assessment of aortic hemodynamics. However, data analysis traditionally requires manual and time-consuming human input at several stages. This limits reproducibility and affects analysis workflows, such that large-cohort 4D flow studies are lacking. Here, a fully automated artificial intelligence (AI) 4D flow analysis pipeline was developed and evaluated in a cohort of over 350 subjects. The 4D flow MRI analysis pipeline integrated a series of previously developed and validated deep learning networks, which replaced traditionally manual processing tasks (background-phase correction, noise masking, velocity anti-aliasing, aorta 3D segmentation). Hemodynamic parameters (global aortic pulse wave velocity (PWV), peak velocity, flow energetics) were automatically quantified. The pipeline was evaluated in a heterogeneous single-center cohort of 379 subjects (age = 43.5 ± 18.6 years, 118 female) who underwent 4D flow MRI of the thoracic aorta (n = 147 healthy controls, n = 147 patients with a bicuspid aortic valve [BAV], n = 10 with mechanical valve prostheses, n = 75 pediatric patients with hereditary aortic disease). Pipeline performance with BAV and control data was evaluated by comparing to manual analysis performed by two human observers. A fully automated 4D flow pipeline analysis was successfully performed in 365 of 379 patients (96%). Pipeline-based quantification of aortic hemodynamics was closely correlated with manual analysis results (peak velocity: r = 1.00, p < 0.001; PWV: r = 0.99, p < 0.001; flow energetics: r = 0.99, p < 0.001; overall r ≥ 0.99, p < 0.001). Bland–Altman analysis showed close agreement for all hemodynamic parameters (bias 1–3%, limits of agreement 6–22%). Notably, limits of agreement between different human observers’ quantifications were moderate (4–20%). In addition, the pipeline 4D flow analysis closely reproduced hemodynamic differences between age-matched adult BAV patients and controls (median peak velocity: 1.74 m/s [automated] or 1.76 m/s [manual] BAV vs. 1.31 [auto.] vs. 1.29 [manu.] controls, p < 0.005; PWV: 6.4–6.6 m/s all groups, any processing [no significant differences]; kinetic energy: 4.9 μJ [auto.] or 5.0 μJ [manu.] BAV vs. 3.1 μJ [both] control, p < 0.005). This study presents a framework for the complete automation of quantitative 4D flow MRI data processing with a failure rate of less than 5%, offering improved measurement reliability in quantitative 4D flow MRI. Future studies are warranted to reduced failure rates and evaluate pipeline performance across multiple centers. Full article

Aging railroad bridges present complex challenges due to advancing deterioration and outdated design assumptions. This study develops a comprehensive analytical approach for assessing an aging steel truss railroad bridge through finite element (FE) modeling, sensitivity analysis, and model updating, supported by field testing. An initial FE model of the bridge was created based on original drawings and field observations. Field testing using a laser Doppler vibrometer captured the bridge’s dynamic response (vibrations and deflections) under regular train traffic. Key structural parameters (material properties, section properties, support conditions) were identified and varied in a sensitivity analysis to determine their influence on model outputs. A hybrid sensitivity analysis combining log-normal sampling and a genetic algorithm (GA) was employed to explore the parameter space and calibrate the model. The GA optimization tuned the FE model parameters to minimize discrepancies between simulated results and field measurements, focusing on vertical deflections and natural frequencies. The updated FE model showed significantly improved agreement with observed behavior; for example, vertical deflections under a representative train were matched within a few percent, and natural frequencies were accurately reproduced. This validated model provides a more reliable tool for predicting structural performance and fatigue life under various loading scenarios. The results demonstrate that integrating field data, sensitivity analysis, and model updating can greatly enhance the accuracy of structural assessments for aging railroad bridges, supporting more informed maintenance and management decisions. Full article

Objectives: The aim of this study was to evaluate the effectiveness of spectrophotometers for objective tooth color measurement, particularly in bleaching procedures enhanced by digital positioning templates. Methods: Tooth color registration was conducted using both subjective methods with shade guides and objective methods with spectrophotometers. Spectrophotometers were chosen for their ability to provide objective, quantifiable, and reproducible results, crucial for monitoring color modifications accurately. Digital workflows were implemented to enhance the registration process further. These workflows included providing a precise positioning matrix for spectrophotometer sensors and optimizing working models to ensure high-quality therapeutic splints. Results: The use of spectrophotometers demonstrated superior performance in registering tooth color objectively compared to subjective shade guides. Digital workflows significantly improved the precision and efficiency of spectrophotometer measurements through a digital matrix, enhancing the quality of therapeutic splints obtained. Conclusions: Spectrophotometers are recommended for objective and precise tooth color registration, particularly in bleaching procedures. Integrating a digital positioning matrix enhances measurement accuracy and reliability, supporting effective monitoring and treatment outcomes. Full article

Echocardiography is the primary imaging modality for diagnosing cardiac disease in children, with quantitation largely based on nomograms. Over the past decade, significant efforts have been made to address the numerical and methodological limitations of earlier nomograms. As a result, robust and reliable pediatric echocardiographic nomograms are now available for most two-dimensional anatomical measurements, three-dimensional volumes, and strain parameters. These more recent nomograms are based on adequate sample sizes, strict inclusion and exclusion criteria, and rigorous statistical methodologies. They have demonstrated good reproducibility with minimal differences across different authors, establishing them as reliable diagnostic tools. Despite these advances, some limitations persist. Certain ethnic groups remain underrepresented, and data for preterm and low-weight infants are still limited. Most existing nomograms are derived from European and North American populations, with sparse data from Asia and very limited data from Africa and South America. Nomograms for preterm and low-weight infants are few and cover only selected cardiac structures. Although diastolic parameter nomograms are available, the data remain heterogeneous due to challenges in normalizing functional parameters according to age and body size. The accessibility of current nomograms has greatly improved with the development of online calculators and mobile applications. Ideally, integration of nomograms into echocardiographic machines and reporting systems should be pursued. Future studies are needed to develop broader, more comprehensive, and multi-ethnic nomograms, with better representation of preterm and low-weight populations, and to validate new parameters derived from emerging three- and four-dimensional echocardiographic techniques. Full article