Test Method Research Articles

A Day Saved is a Life Saved: Direct Antimicrobial Susceptibility Testing from Positively Flagged Blood Culture Bottles and their Concordance with the Routine Method.

Sepsis is a major health problem worldwide and is associated with high morbidity and mortality with every hour delay in initiation of therapy. A conventional method of blood culture and Antimicrobial Susceptibility Testing (AST) takes around 48-72 hours. Empirical antibiotics need to be administered until the sensitivity report is made available. It has been estimated that 20-50% of the empirical antibiotics are inappropriate, resulting in prolonged hospital stays, adverse effects, and emergence of drug resistance. Additionally, this also puts an extra financial burden on both the patients and healthcare settings. Performing direct Antimicrobial Sensitivity Testing (dAST) is an important tool to reduce turn-around time (TAT) by at least 18-24 hours, thus reducing morbidity and mortality among critically ill patients. Direct AST (dAST) was performed from the positively flagged blood culture bottles received between December, 2021 to May, 2022 from Intensive Care Units (ICUs) on Mueller- Hinton Agar (MHA) using four drops of withdrawn blood. dAST was performed for six drugs: Ceftriaxone-30 μg (CTR), Piperacillin/Tazobactam-100/10 μg (PIT), Meropenem-10 μg (MRP), Ciprofloxacin-5 μg (CIP), Aztreonam-30 μg (AT), and Colistin (CL). The zone of inhibition was interpreted as per CLSI M100 ed32, 2022 guidelines. A parallel conventional method was also performed to examine for categorical agreement and disagreement. Identification was carried out using MALDI-TOF MS from the colonies that appeared on the dAST plate on the subsequent day. A total of 162 positively flagged blood culture bottles were included in the study. The majority of the Gram-negative organisms were from Enterobacterales (n=109), followed by Acinetobacter spp. (n=28) and Pseudomonas aeruginosa (n=25). Out of the 972 isolate-antimicrobial combinations, overall Categorical Agreement (CA) was seen in 936 (96.3%), whereas disagreement was observed in 36 with minor error (mE) in 21 (2.2%), major error (ME) in 7 (0.7%), and very major error (VME) in 8 (0.8%) when compared to the routine method. Categorical agreement (CA) of > 99% was seen in ceftriaxone (CTR) and ciprofloxacin (CIP). In comparison, the lowest CA was observed with meropenem (MRP) at 92%. Colistin dAST was performed using the E-strip method, and the result obtained was highly convincing, with an overall disagreement of only 1.2%. Rapid dAST from positively flagged blood culture bottles proved to significantly reduce the TAT from the time of sample collection to the first availability of antimicrobial susceptibility report with excellent categorical agreement of > 95% using the conventional disc diffusion method. Results obtained were within the acceptance criteria set by U. S. Food and Drug Administration (FDA) guidelines of > 90% categorical agreement for a new method. We were able to obtain excellent concordance for colistin using the E-strip method. Performing dAST not only saves a "day", but its proper implementation would save a "life".

Can artificial intelligence and green finance affect economic cycles?

The COVID-19 recession and the Ukraine-Russia War (URW) crisis have added a new layer of complexity to global economic cycles, necessitating the evolution of economic systems and proactive responses to emerging economic challenges. In this context, the recent article introduces artificial intelligence (AI) as a new driver of economic cycles and analyzes its dynamic role alongside the Belt and Road Initiative (BRI), the Paris Agreement (PA), green finance (GB), and economic shocks (ES) in determining global economic cycles. The article employs novel econometric tools, namely the CAViaR-TVP-VAR model, the Quantile Coherence method, panel Quantile on Quantile Kernel-Based Regularized Least Squares (PQQKRLS), and the Quantile-Quantile Granger causality (QQGC) test for robust findings. The outcomes reveal that AI influences economic cycles in the short run while significantly mitigating these cycles in the medium and long run. Furthermore, the BRI exhibits a positive link with economic cycles during the short and medium run; however, it can contribute to economic stability in the long run by impeding economic fluctuations. Similarly, green finance and the PA show mixed influences across various time horizons, except for the long run, which confirms their negative association with economic cycles. Additionally, ES has a direct link with economic cycles across most periods. The robustness check based on the QQGC test and PQQKRLS method supports the main results. Our results identify AI, BRI, and the PA as new drivers of economic cycles with the potential to counter global economic cycles. Therefore, based on these findings, the study proposes several policy implications tailored to different time horizons.

Automation of Biochemical Assays Using an Open-sourced, Inexpensive Robotic Liquid Handler.

High Throughput Screening is crucial in pharmaceutical companies for efficient testing in drug discovery and development. Our Vaccines Analytical Research and Development Department (V-AR&D) extensively uses Robotic Liquid Handlers in their High Throughput Analytics (HTA) group for assay development and sample screening. However, these instruments are expensive and require extensive training. Opentrons' OT-2 liquid handler offers a more affordable option (< $10,000) with Python programming language and open-source flexibility, reducing training requirements. OT-2 allows broadening of testing capabilities and method transfer without significant capital investments. Two biochemical assays were conducted to assess OT-2′s performance, and it demonstrated accurate pipetting with low covariance compared to Tecan-EVO liquid handlers. Though OT-2 has some limitations such as lack of a crash detection system and limited deck space, it is a cost-effective, medium-throughput, and accurate liquid handling tool suitable for early-stage development and method transfer.

Heat treatment effects on the shear performance and microstructure evolution of W-core SiC fibers

SiC fiber reinforced titanium alloy matrix composites employed in elevated temperature aeroengine components are subjected to complex loading conditions. Investigating the shear performance of SiC fibers after heat treatment can help ensure the load-carrying capability of composites at service temperatures. This study presents a novel double shear testing method for W-core SiC fibers. The shear strength and stiffness of the SiC fibers in as-received and heat-treated conditions were measured. The morphologies of SiC fibers’ shear fracture surfaces and C coatings were thoroughly analyzed. The evolution of the internal microstructure and the composition of reaction layers after heat treatments were investigated. The shear strength of W-core SiC fibers at 95% survival probability reached 588.64MPa after 200 h of heat treatment at 600°Celsius, representing a 55% improvement over both the as-received and 1100°Celsius heat-treated conditions. After heat treatment at 1100°Celsius, the reaction layer between the W core and the SiC sheath thickened exponentially due to extensive elemental diffusion, resulting in the formation of numerous Kirkendall voids. The voids facilitated crack initiation and propagation, leading to a deterioration in fiber shear performance. The insights gained in this study regarding the shear properties of SiC fibers can provide support for predicting the mechanical performance of composites under complex loading conditions.

An Alternative Junction-to-Case Thermal Resistance Test Method for High Power Press-Pack IGBTs

An Alternative Junction-to-Case Thermal Resistance Test Method for High Power Press-Pack IGBTs

The diagnostic performance of the Visitect Advanced Disease point-of-care CD4 platform: a pragmatic mixed-methods multisite validation, costing, and qualitative analysis.

The Visitect CD4 Advanced Disease test (AccuBio, Alva, United Kingdom) is a rapid, semi-quantitative assay that estimates CD4 results above or below 200 cells/μL. We evaluated the performance of the Visitect CD4 assay in semi-urban laboratories in Uganda. We performed a pragmatic laboratory validation of the Visitect CD4 platform in four routine HIV clinics in Uganda, nested within a cluster randomized trial evaluating an enhanced package of screening and treatment for persons with advanced HIV disease (NCT05085171). As part of the clinical trial, samples processed on the Visitect CD4 platform were confirmed using another CD4 testing method. We compared the diagnostic performance of the Visitect CD4 platform against the confirmatory method by evaluating the sensitivity, specificity, positive and negative predictive values. Of 1495 venous blood samples that were processed both by the Visitect CD4 test and another confirmatory CD4 platform at clinics in Kampala, Uganda, specificity was 81% (95% CI, 79%-84%) and the positive predictive value was 69% (95% CI, 66%-73%). There were no samples for which the Visitect test was >200 cells/μL and the confirmatory test was ≤200 cells/μL, resulting in a sensitivity of 100%. Among Visitect CD4 tests that were read as <200 cells/μL with confirmatory results >200 cells/μL, the median confirmatory CD4 result was 397 (IQR, 281-590) cells/μL. Specificity varied by clinic ranging from 63% to 99%. Given variable specificity of the Visitect CD4 Advanced Disease platform, successful implementation will require consideration of clinic context and laboratory staffing.

The relationship between lead levels and reading acquisition in Spanish speakers, evidence from Uruguayan schoolers.

To investigate the cross-sectional association between blood lead levels (BLL), and pre-reading and reading abilities in first-grade children from Montevideo, Uruguay. Of 357 school children (age 67-105 months) enrolled into the study, 287(43 % girls) had a BLL measure and an assessment of pre-reading and reading abilities based on five tests (Verbal comprehension, Sound blending, Letter word identification, Sentence reading fluency, and Passage comprehension) from the Batería III Woodcock-Muñoz. Separate generalized linear models (GLM) were conducted on the relationship between BLL and each test score separately, adjusting for sex, maternal education, household assets, Home Observation for Measurement of the Environment Inventory score, season, test administrator, blood lead testing method, and school clusters. The mean BLL was 4.0 ± 2.2 µg/dL, with no differences between the sexes. BLL was associated with a poorer vocabulary knowledge (β [95 % CI]): -0.20 [-0.39, 0.01]. For all the tests, children with BLLs ≥5 µg/dL tended to exhibit poorer performance than children with lower BLLs, but these associations were not statistically significant. When stratified by sex, some evidence of differential associations between BLLs and reading abilities emerged: BLLs were associated with higher phonological awareness in girls (0.32 [0.15, 0.48]) but not boys, and with lower reading comprehension in boys (-0.54 [-1.20, 0.13]) but not girls. Also, lead exposure (BLL ≥ 5 µg/dL) was more strongly and negatively associated with phonological awareness (-1.22 [-1.57, -0.86]) in boys than girls. In this study of first-grade children learning to read in Spanish, we found an inverse association between lead exposure and vocabulary scores, as well as tendency toward lower performance on pre-reading and reading measures among children with BLLs ≥5 µg/dL. Pre-reading and reading abilities are relevant to literacy acquisition; further research is required to confirm these links in larger studies, and to investigate differences between boys and girls, and according to key sociodemographic characteristics.

Assessment of cutting force coefficient identification methods and force models for variable pitch and helix bull-nose tools

The mechanistic approach is commonly implemented to predict and optimise the cutting forces in milling processes to prevent tool breakages, reduce tool wear, reduce form error, and improve surface quality. To implement this method, the cutting force coefficients (CFCs), that characterise the mechanics of the process, must be calculated. This study compares the accuracy of the predicted cutting forces for variable pitch and helix bull-nose milling tools using a rapid testing (RT) optimisation-based mechanistic CFC identification method that only requires a single angular cut with increasing radial engagement to the traditional mechanistic approach that requires several straight cuts. Along with developing a hybrid technique that combines variation in feed rate and radial engagement. The traditional radial, tangential, and axial (RTA) force model is also compared with the frictional and normal rake face (UV) force model that is independent of the local tool rake and inclination angles which is a necessary for bull nose tools. The RT and the developed hybrid CFC identification method with the UV force model predicted the average Fx, Fy and Fz cutting forces to within 7.1 %, 4.3 %, and 3.8 % error, respectively. These methods were slightly less accurate than the traditional method, however they have significant industrial benefits because they have can be used to identify CFCs with either a single cut, or from any tool-path with chip-load variation, respectively. The RTA force model predicted the average cutting forces similarly to the UV force model, however, the UV force model had lower errors using the rapid RT testing method at the extreme corners of the experimental design space.

In silico Exploration of a Novel ICMT Inhibitor with More Solubility than Cysmethynil against Membrane Localization of KRAS Mutant in Colorectal Cancer.

ICMT (isoprenylcysteine carboxyl methyltransferase) is an enzyme that plays a key role in the post-translational modification of the K-Ras protein. The carboxyl methylation of this protein by ICMT is important for its proper localization and function. Cysmethynil (2-[5-(3-methylphenyl)-l-octyl-lH-indolo-3-yl] acetamide) causes K-Ras mislocalization and interrupts pathways that control cancer cell growth and division through inhibition of ICMT, but its poor water solubility makes it difficult and impractical for clinical use. This indicates that relatively high amounts of cysmethynil would be required to achieve an effective dose, which could result in significant adverse effects in patients. The general objective of this work was to find virtually new compounds that present high solubility in water and are similar to the pharmacological activity of cysmethynil. Pharmacophore modeling, pharmacophore-based virtual screening, prediction of ADMET properties (absorption, distribution, metabolism, excretion, and toxicity), and water solubility were performed to recover a water-soluble molecule that shares the same chemical characteristics as cysmethynil using Discovery Studio v16.1.0 (DS16.1), SwissADME server, and pkCSM server. In this study, ten pharmacophore model hypotheses were generated by exploiting the characteristics of cysmethynil. The pharmacophore model validated by the set test method was used to screen the "Elite Library®" and "Synergy Library" databases of Asinex. Only 1533 compounds corresponding to all the characteristics of the pharmacophore were retained. Then, the aqueous solubility in water at 25°C of these 1533 compounds was predicted by the Cheng and Merz model. Among these 1533 compounds, two had the optimal water solubility. Finally, the ADMET properties and Log S water solubility by three models (ESOL, Ali, and SILICOS-IT) of the two compounds and cysmethynil were compared, resulting in compound 2 as a potential inhibitor of ICMT. According to the results obtained, the identified compound presented a high solubility in water and could be similar to the pharmacological activity of cysmethynil.

Correlation and application of thermal expansion coefficient/elastic modulus for co-sintered composite cermet/ceramic materials

Deformation and stress concentration appearing during high-temperature sintering process significantly affect production quality of solid oxide cell (SOC), due to mismatched mechanical and thermophysical properties of the sintered electrode and electrolyte. In this study, a coarse-grained molecular dynamics (CG-MD) method is developed to evaluate and correlate coefficient of thermal expansion (CTE) and elastic modulus during the entire co-sintering process (including temperature-increasing, −insulation, and -decreasing stages). It is revealed that, in the sintered porous cermet electrode, CTE primarily exhibits an increasing trend until temperature-decreasing stage. Compared to the constant values commonly applied in the literature, the elastic modulus experiences a decay trend with a reduction of 32.14 % in the porous electrode and 9.68 % reduction in the dense electrolyte. The obtained CTE and elastic modulus are correlated with the sintering parameters and further applied to a macroscopical model for predicting overall sintering warpage and stress in a co-sintered SOC half-cell composed of a thick porous electrode and a thin dense layer. The varied CTE is identified as the main factor influencing warpage deformation, while the elastic modulus as a more significant impact on the von Mises stress during the co-sintering of the half-cell. Analysis is further conducted by orthogonal testing method for sintering temperature, sintering time, material content and diameter ratio of the porous cermet nanoparticles, aiming to optimize the varied CTE and elastic modulus, particularly during the temperature-insulation process. Subsequently, the optimized properties are implemented, and it is found that, after sintering insulation for 120 min, the maximum warpage displacement is about 7.34 mm, which represents a decrease of approximately 14.11 %; while the von Mises stress is observed to be 379.24 MPa, which indicates a reduction of around 37.33 % compared with the predictions by the constant properties.

Carbon dioxide capture in sodium carbonate solution: Mass transfer kinetics and DTAC surfactant enhancement mechanism

Sodium carbonate solvent absorbent has been widely studied for CO2 reduction to deal with global warming because of its green, low cost, and non-corrosive advantages. However, in the application of sodium carbonate as an absorbent for CO2 capture, there is no unified cognition of the mass transfer process, which leads to the lack of guidance for the industrial large-scale process. Moreover, the mechanism of mass transfer enhancement of surfactants, which can effectively improve the mass transfer performance, has not been effectively explored in the literature. Based on this, this paper firstly adopts the molecular dynamics method to analyze the solution characteristics after surfactant addition and optimize the surfactant. Subsequently, a classical dissolved oxygen test method was used to measure the gas-liquid mass transfer coefficient for CO2 absorption into sodium carbonate solution. And based on this mass transfer coefficient measurement method, the mass transfer process of sodium carbonate solution with surfactant was analyzed. The results showed that the sodium carbonate solution with 5 wt% concentration and 10 wt% concentration at 30 °C did not satisfy the pseudo first-order fast chemical reaction kinetics assumption. To improve CO2 absorption mass transfer rate, dodecyl trimethyl ammonium chloride (DTAC) surfactant was introduced, which was improved by 119 % compared with non-enhanced solvent at 5 wt% concentration solution, and the assumption of pseudo first order fast chemical reaction was satisfied. After the introduction of surfactant, the barrier effect decreased the liquid phase mass transfer coefficient, but the Marangoni effect happened in the 5 wt% concentration of sodium carbonate solution, which enhanced the liquid-phase mass-transfer coefficient. This finding reveals the mechanism of mass transfer promotion of sodium carbonate by the surfactant DTAC, which is of great engineering significance for the application in the field of decarbonization after the introduction of surfactant.

Optimization of ventilation and dust removal parameters in plateau extra-long tunnel inclined shaft based on orthogonal numerical simulation test method

Ventilation and dust removal system in the inclined shaft of the plateau long tunnel is an important component for ensuring safe excavation. The arrangement of wind tube and the volume of air flow have a significant impact on the movement of dust. In order to address the issues of poor ventilation and severe dust pollution in the inclined shaft of plateau long tunnels, this study establishes a dust generation and transportation model for the face of the inclined shaft based on the determination of dust source parameters and their physicochemical characteristics during the excavation process. The results indicate that the particles are predominantly spherical with an approximate diameter of 4 μm at a magnification of 500 times. The dust in high-altitude inclined shafts exhibits poor wettability, with a hydrophobic tendency during the excavation phase, making a ventilation dust removal scheme appropriate. After determining the physical parameters corresponding to the elevation of the inclined shaft, a series of orthogonal numerical simulations involving 3 factors at 5 levels were conducted. Analysis of range and variance revealed that optimal dust control is achieved when the air duct height is 5.725m, the distance from the working face is 21m, and the exit wind speed is 29.71m/s. Comparative analysis confirmed the rationality of the ventilation dust removal scheme under the optimal combination of ventilation parameters. This provides guidance for engineering and environmental management in similar construction scenarios.

New impulse-based test method for early-age elastic modulus measurement in cementitious materials

Accurate monitoring of the elastic modulus evolution during the early-age fluid-solid transition in cementitious materials is crucial for understanding their mechanical behavior under early stresses. While existing methods, such as EMM-ARM, have proven effective, they are often associated with high costs or complex setups. This study presents the development of a low-cost, easy-to-implement system that employs impulse excitation applied to a composite beam, introducing the EMM-IRM method for the effective assessment of the elastic modulus of cement paste from the earliest stages of hydration. The use of impulse excitation is particularly advantageous in low-cost systems with accelerometers of lower sensitivity, as it enhances signal clarity and reduces interference from background noise, thereby improving measurement reliability. The system was validated through experimental comparisons with conventional EMM-ARM, cyclic compression, and traditional impulse excitation techniques, using Portland cement paste as the test material. The results show that EMM-IRM consistently estimates the elastic modulus, with a maximum deviation of 6.33% from other methods. Moreover, despite its cost-effectiveness, EMM-IRM demonstrates a higher signal-to-noise ratio compared to conventional EMM-ARM. This approach offers a practical solution for early-age characterization of cementitious materials, balancing cost, simplicity, and measurement accuracy.

Aloe Vera as a Printed Coating to Mitigate the Wear of Textiles

Aloe vera is well known for its biological properties as a bioflavonoid anti-inflammatory and antibacterial agent. It has been used frequently in the food sector as a food coating due to its hygroscopic properties and as an ingredient in the lucrative cosmetic industry. Studies have also included aloe vera as an eco-friendly green solution based on these properties. The current research focuses on the use of aloe vera gel in printing pastes as an alternative sustainable solution to synthetic thickeners, evaluating its wet performance and ease of fabric stitching, and has been inspired by studies that similarly used this substance and measured its effect on the fabric’s coefficient of friction and antimicrobial action. In the current study, printing pastes with natural colourants, such as saffron, curcumin, and annatto, and aloe vera gel thickener derived from natural leaves from Crete increased the fabric’s mechanical resistance to abrasion compared to the untreated pastes. The measured performance did not differ substantially from prints with traditional synthetic pastes, hence tolerating the substitution with the non-contaminant variant. The enhanced resistance to abrasion and wear extends the fabric’s serviceable life and resulting garments, decreasing the need for high industry processing volumes and, as a result, reducing pollution. The resistance to wear was evaluated using the dominant method in textile testing of the Martindale apparatus, which measured the cycles to failure, weight loss, and general appearance deterioration using the official photographic standards.

In-vivo evaluation of analgesic and anti-inflammatory activities of the 80% methanol extract of Acacia seyal stem bark in rodent models

Abstract Background Pain and inflammation are the major medical condition commonly addressed with traditional remedies. Acacia seyal is a traditional herb widely used in Ethiopian folk medicine for pain management. However, its effectiveness has yet to be validated through scientific or experimental research. Therefore, the current study aims at evaluating the in vivo analgesic and anti-inflammatory effects of 80% methanolic stem bark extract of Acacia seyal in rodent models. Methods After successful extractions of the stem barks of Acacia seyal with 80% methanol, the pain relieving effects of 100, 200 and 400 mg/kg extract were evaluated using acetic acid-induced writhing test and hot plate method whereas the anti-inflammatory profile was determined by carrageenan induced paw-edema model and cotton pellet induced granuloma technique. Results The 80% methanol Acacia seyal stem bark extract exhibited substantial (p &lt; 0.001) analgesic effect in acetic acid induced writing test (p &lt; 0.001). The plant extract also witnessed significant central analgesic effect in hot plate method beginning at 30 min with maximum % elongation time occurred at 120 min. Furthermore, the acacia stem bark extract produced anti-inflammatory effect against carrageenan induced paw-edema model. In cotton pellet induced granuloma model, the 200 and 400 mg/kg doses of the current plant material appeared to inhibit granuloma mass formation and exudate reduction significantly (p &lt; 0.001). Conclusion The collective findings of the current study revealed that 80% methanol extracts of Acacia seyal exhibited considerable analgesic and anti-inflammatory activities, supporting the plant’s traditional use for management of pain and inflammatory disorders.

Substantive Dimethicone-Based Mucoadhesive Coatings

It is challenging to deliver therapeutics in the oral environment due to the wet surfaces, the nature of the mucosa and the potential for saliva washout. In this study, the development of a mucoadhesive dimethicone-based oral carrier system for adhesion to the hard tissue and mucosa in the mouth was examined. This study reports the viscosity and mucoadhesion of dimethicone based polymer blends. The viscosity of the materials was measured using a rheometer. The mucoadhesion of these materials was determined as the work of adhesion and peak tack force using the tensile test method with a texture analyzer. Materials were prepared with either calcium and phosphate salts or sodium fluoride as potential therapeutics for promoting remineralization and treating dentin hypersensitivity by mechanical occlusion. Scanning electron microscopy was used to look at mineral deposition on the surface of dental hard tissue after the application of the dimethicone-based formulations. The results of this study confirm the potential for using these dimethicone-based materials as mucoadhesive therapeutic delivery systems in the oral environment.

Self‐similar traffic prediction for LEO satellite networks based on LSTM

AbstractTraffic prediction serves as a critical foundation for traffic balancing and resource management in Low Earth Orbit (LEO) satellite networks, ultimately enhancing the efficiency of data transmission. The self‐similarity of traffic sequences stands as a key indicator for accurate traffic prediction. In this article, the self‐similarity of satellite traffic data was first analyzed, followed by the construction of a satellite traffic prediction model based on an improved Long Short‐Term Memory (LSTM). An early stopping mechanism was incorporated to prevent overfitting during the model training process. Subsequently, the Diebold‐Mariano (DM) test method was applied to assess the significance of the prediction effect between the proposed model and the comparison model. The experimental results demonstrated that the improved LSTM satellite traffic prediction model achieved the best prediction performance, with Root Mean Squared Error values of 18.351 and 8.828 on the two traffic datasets, respectively. Furthermore, a significant difference was observed in the DM test compared to the other models, providing a solid basis for subsequent satellite traffic planning.

Research and application of a new method for axial force test of prestressed high-strength concrete pipe piles.

In order to figure out actual shaft resistance, axial forces of pile shaft have to be calculated based on strain test, which is a challenge for heat and steam cured prestressed high-strength concrete pipe piles. Disadvantages of three common methods of strain test and the empirical linear equation between axial force and strain are analyzed. A new strain test method, namely the slot-forming wood method, is proposed and applied in laboratory and field test. Taking pipe pile PHC500AB-125 as an example, laboratory tests were performed to establish the nonlinear function between axial force and strain. Field tests were performed and strains were tested by the slot-forming wood method. Results calculated by the nonlinear function between axial force and strain were compared with that by traditional linear equation to reveal the difference. The tests indicated that the new method of strain test was applicable and useful since the survival rate of strain gauges was high and the accuracy has been improved. Overcoming the disadvantages of the traditional linear equation, the proposed function between axial force and strain is more accurate. The study provides theoretical basis for technology innovation in pile test and for revision of related technical standards.

Repeatability of Microperimetry in areas of RPE and Photoreceptor loss in Geographic Atrophy supported by AI-based OCT biomarker quantification.

Growing interest in microperimetry (MP) or fundus-controlled perimetry (FCP) as targeted psychometric testing method in geographic atrophy (GA) is warranted due to the disease subclinical/extra-foveal appearance or preexisting foveal loss with visual acuity becoming unreliable. We provide comprehensive pointwise test-retest repeatability reference values on the most widely used MP devices and combine them with targeted testing in areas of retinal pigment epithelium (RPE) as well as photoreceptor (PR) integrity loss, guiding the interpretation of sensitivity loss during the long-term follow-up of GA patients. Prospective reliability study METHODS: Patients with GA underwent consecutive testing on CenterVue (iCare) MAIA and NIDEK MP3 devices. Obtained PWS measurements were spatially co-registered to an optical coherence tomography (OCT) volume scan acquired during the same visit. Areas with RPE and PR integrity loss, drusen and PR thickness as well as the volume of hyperreflective foci (HRF) where identified and quantified using a set of validated deep learning-based algorithms. Test-retest repeatability was assessed according to areas defined by biomarker-specific morphologic changes using Bland-Altmann coefficients of repeatability (CoR). Furthermore, the inter-device correlation, the repeatability of scotoma point detection as well as any potential effects on fixation stability were assessed. 900 stimuli per device from twenty subjects were included. Identical overall PWS test-retest variance could be detected for MAIA (±6.57) and MP3 (±6.59). PR integrity loss was associated with a higher test-retest variance on both devices (MAIA: p=0.002; MP3: p<0.001). Higher CoR for stimuli in areas presenting RPE loss (±10.99 vs ±5.34) or HRF (±9.21 vs ±6.25) could only be detected on MP3 examinations (p<0.001 and p=0.01, respectively). An excellent intra-device correlation (MAIA: 0.94[0.93-0.95] MP3: 0.94[0.94-0.95]) and a good mean inter-device correlation (0.84[0.53-0.92]) could be demonstrated. The chosen device, run order or absence of foveal sparing had no significant effect on fixation stability. Areas presenting automatically quantified PR integrity loss with and without underlying RPE loss are associated with higher test-retest variance for both MAIA and MP3. These findings are crucial for an accurate interpretation of GA progression during long-term follow-up and the planning of future trials with microperimetry testing as functional study endpoint.

An Optical-Electrochemical Microbiological Test Method Applied to Assessment of the Properties of Various Essential Oils

An Optical-Electrochemical Microbiological Test Method Applied to Assessment of the Properties of Various Essential Oils