Laboratory Applications Research Articles

Grid Turbulence Measurements with an Acoustic Doppler Current Profiler

The motivation for this study is to investigate the abilities and limitations of a Nortek Signature1000 acoustic Doppler current profiler (ADCP) regarding fine-scale turbulence measurements. Current profilers offer the advantage of gaining more coherent measurement data than available with point acoustic measurements, and it is desirable to exploit this property in laboratory and field applications. The ADCP was tested in a towing tank, where turbulence was generated from a grid towed under controlled conditions. Grid-induced turbulence is a well-studied phenomenon and a good approximation for isotropic turbulence. Several previous experiments are available for comparison and there are developed theories within the topic. In the present experiments, a Nortek Vectrino acoustic Doppler velocimeter (ADV), which is an established instrument for turbulence measurements, was applied to validate the ADCP. It was found that the mean flow measured with the ADCP was accurate within 4% of the ADV. The turbulent variance was reasonably well resolved by the ADCP when large grid bars were towed at a high speed, but largely overestimated for lower towing speed and smaller grid bars. The effective cutoff frequency and turbulent eddy size were characterized experimentally, which provides detailed guidelines for when the ADCP data can be trusted and will allow future experimentalists to decide a priori if the Nortek Signature can be used in their setup. We conclude that the ADCP is not suitable for resolving turbulent spectra in a small-scale grid-induced flow due to the intrinsic Doppler noise and the low spatial and temporal sample resolution relative to the turbulent scales.

Spheroids formation in large drops suspended in superhydrophobic paper cones.

The utilization of 3D cell culture for spheroid formation holds significant implications in cancer research, contributing to a fundamental understanding of the disease and aiding drug development. Conventional methods such as the hanging drop technique and other alternatives encounter limitations due to smaller drop volumes, leading to nutrient starvation and restricted culture duration. In this study, we present a straightforward approach to creating superhydrophobic paper cones capable of accommodating large volumes of culture media drops. These paper cones have sterility, autoclavability, and bacterial repellent properties. Leveraging these attributes, we successfully generate large spheroids of ovarian cancer cells and, as a proof of concept, conduct drug screening to assess the impact of carboplatin. Thus, our method enables the preparation of flexible superhydrophobic surfaces for laboratory applications in an expeditious manner, exemplified here through spheroid formation and drug screening demonstrations.

A novel three-dimensional isolation bearing for buildings subject to metro- and earthquake-induced vibrations: Laboratory test and application

The implementation of three-dimensional (3D) isolation technology effectively enhances the structural seismic resilience and mitigates the impact of vibrations induced by metro trains. However, the challenge remains to increase the vertical loading capacity of 3D isolation bearings while reducing their vertical stiffness and guaranteeing excellent stability. The 3D isolation bearing (3DIB) consisting of an improved laminated natural rubber bearing (LNR-400-imp) and spring bearings (SBs) built vertically in series were proposed in this study. Its design principle and working mechanism were introduced, and prototype specimens were designed and manufactured. The 3D mechanical performance of the 3DIB was investigated through horizontal and vertical tests. Furthermore, the earthquake and metro vibration isolation performances of the building installed with the 3DIB were analyzed using a case study. The results demonstrated that the 3DIB exhibited horizontal energy dissipation effect, and had stable vertical performance, higher vertical loading capacity, and lower vertical stiffness attributing to the improved LNR-400-imp and SBs. Specifically, the vertical stiffness of the 3DIB was about 1/14 of that of the traditional LNR-400-tra. The case study demonstrated that the 3DIB had remarkable earthquake and metro vibration isolation effects, behaving huge potentials in enhancing the seismic resilience of structures and mitigating the impact of metro vibrations. This study offers valuable insight and practical guidance for future research on 3DIB in the field of vibration isolation, contributing to the advancement of 3D isolation technology.

Prioritizing competencies for soldier's mental resilience: an application of integrative fuzzy-trapezoidal decision-making trial and evaluation laboratory in updating training program.

The development of resilience is of the utmost importance in military training due to the demanding and high-stress nature of combat situations. Although there have been numerous studies on resilience competencies in the military, there is a research gap when it comes to identifying the most essential competencies that should be prioritized in training programs, particularly within compressed timeframes. With the current geopolitical landscape and ongoing military conflicts in Europe, it is necessary to expedite training of soldiers, including resilience training, without compromising the effectiveness of the program. This study aims to address this research gap by using a reductionist approach to resilience training and identifying the critical competencies that senior soldiers need to be trained to coach younger soldiers to maintain psychological strength during deployment. By filling this research gap, the study will contribute to the development of more efficient and targeted resilience training programs that optimize the ability of soldiers to adapt and excel in challenging military environments. To address the issue, this study assessed the competencies comprising the master resilience training (MRT) program, widely recognized as one of the most effective military resilience training programs. Two groups of military experts, totaling 16 individuals, were involved in the evaluation process, representing two military contexts. The first group consisted of Ukrainian military experts whose experiences primarily focused on defending their own country's territory. The second group comprised Lithuanian military experts who had greater expertise in conducting military missions abroad. The assessment of resilience competencies was carried out using a deep analysis approach through the application of effective multi-criteria decision making (MCDM). Specifically, the decision-making trial and evaluation laboratory (DEMATEL) method was used, which is a significant multicriteria technique used to determine relationships among criteria and assign weight coefficients. In this study, the DEMATEL model was extended using trapezoidal fuzzy numbers (TrFN-DEMATEL) to accommodate decision-making under uncertainty conditions. The research findings highlight the critical importance of three core resilience competencies: self-regulation, mental agility and strength of character. The importance of each competency varies depending on the specific military context. When defending one's own country's territory, strength of character emerges as the key factor in enhancing soldiers' mental resilience. Conversely, during military operations abroad, self-regulation is the primary factor that promotes psychological resilience. Furthermore, the results show that these three primary competencies form a 'cause group' that influences other competencies through a cause-and-effect dependency. Based on the findings, the theoretical conclusion is drawn that the importance of resilience competencies is contextually differentiated. Furthermore, each resilience competency is associated with a set of causes or effects. These are valuable insights for improving resilience competency training programs.

Review of the potential benefits and challenges of artificial intelligence in clinical laboratory

Over the past few years, medical artificial intelligence (AI) has been extensively utilized within the healthcare industry. However, the deployment of AI raises complicated social and ethical issues related to security, privacy, and human rights. While the use of artificial intelligence (AI) has the potential to improve healthcare outcomes and operational efficiency, this article gives a detailed assessment of current cutting-edge AI breakthroughs in clinical laboratories. It focuses on the potential benefits of AI and its application in clinical laboratory. The use of AI in clinical laboratory is rapidly growing, with the potential to alter patient care in the near future. Furthermore, it has the potential to democratize modern laboratory services, making them available to people all around the world.

Continual preparation of chemical vapor standard mixtures: Autonomous generator based on modified dynamic methods

Many applications in laboratory, industrial and R&D practice involve utilization of standard chemical vapor mixtures, therefore their availability, ease of preparation and reliability play a crucial role. This work is presenting a new instrumentation based on the innovated dynamic preparation method using the injection of liquid sample, fast evaporation, and uniform mixing with carrier gas. The combination of precise syringe drives, quantitative evaporation and controlled flow of carrier gas provides very high level of accuracy and stability of the generation process. The system is robust with minimal requirements for calibration, and it is suitable for producing single or multi component mixtures.

Experimental Studies and Application of Fiber-Reinforced Polymers (FRPs) in Civil Infrastructure Systems: A State-of-the-Art Review.

The application of FRPs in civil infrastructure has increased, particularly in the last 20 years. FRPs have gained importance because of their resistance to harsh environments, high strength-to-weight ratio, and good corrosion resistance, and they are faster and easier to apply than other traditional methods. The rehabilitation of structures is the main area in which FRPs have been developed, because they have allowed for compliance with architectural restraints in historic structures. This review is a compilation of the research conducted on the laboratory and field applications of FRPs, highlighting the different applied methods, installation difficulties, and failure modes of FRPs. Moreover, this review compares studies on the types of fibers such as CFRPs, GFRPs, and AFRPs, and their effects would affect the mechanical properties of civil infrastructure and the durability characteristics of civil infrastructure in challenging environmental conditions. In addition, this review focuses on the modification of the mechanical properties of structural elements using different methods of installing FRPs, including externally bonded reinforcement (EBR), and their main problem: debonding failure before the ultimate load.

The Effect of Video-Based Laboratory Application on Self-Efficacy and Self-Learning in Nursing Students: A Comparative Study

ABSTRACT The aim of this study is to determine the effect of video-based laboratory practice activities in distance education on nursing students’ self-efficacy and self-learning. A randomized controlled trial of intervention and control groups with pretest, posttest study. The study sample consisted of 118 nursing students registered to the online Pediatric Nursing distance education in the 2022–2023 academic year. This study was completed with the participation of 100 students, with 56 students in the video group and 44 students in the control group. In the distance education, video-based laboratory application was applied to the students in the video group. The students did a video application about 8 topics related to child health and diseases nursing. The students in the control group did not video based laboratory application, only did classic education. At the beginning and end of the study, Self-Directed Learning Instrument (SDLI) and (General Self-Efficacy Scale (GSES) were applied to the students. The difference between the GSES and SDLI total and subscales pre and posttest difference mean scores were found to be higher for nursing students in the study group compared to those in the control group (p < .001).

Potential usage of fly ash and nano silica in high-strength concrete: Laboratory experiment and application in rigid pavement

High-strength concrete (HSC) using supplementary cementitious material of 30% fly ash (FA) and various nano silica (NS) contents were investigated in this study. FA and NS are waste materials collected from local thermal plants and rice husk ash in Southern Vietnam, respectively. Different concentrations of NS at 0%, 0.5%, 1.0%, and 1.5% were incorporated into the base mixture in place of cement and FA. The water-to-binder ratio of 0.32 was constant for all the mixtures. Results indicated that the combination binder of cement, FA, and NS satisfied the setting time as pure cement binder. The slump test value was in the range of 30–40 mm by adjusting the superplasticzer. Mechanical properties of HSC were studied at various curing ages of 3, 7, 28, and 56 days, including compressive strength, flexural strength, elastic modulus, and abrasion resistance. Results indicated that 1% NS can be considered as optimum content for preparing an HSC mixture, which showed the best mechanical properties. Furthermore, a good correlation between compressive strength and flexural strength was obtained from the results. Finally, rigid pavement calculation revealed that the addition of 1% NS resulted in a reduction in the thickness of the concrete slab by 30 mm (around 10.7%) compared to non-NS concrete. These findings suggest that incorporating nano-silica into concrete can lead to thinner concrete slabs with improved performance characteristics.

Deep Learning-Based Lumen and Vessel Segmentation of Intravascular Ultrasound Images in Coronary Artery Disease.

Intravascular ultrasound (IVUS) evaluation of coronary artery morphology is based on the lumen and vessel segmentation. This study aimed to develop an automatic segmentation algorithm and validate the performances for measuring quantitative IVUS parameters. A total of 1,063 patients were randomly assigned, with a ratio of 4:1 to the training and test sets. The independent data set of 111 IVUS pullbacks was obtained to assess the vessel-level performance. The lumen and external elastic membrane (EEM) boundaries were labeled manually in every IVUS frame with a 0.2-mm interval. The Efficient-UNet was utilized for the automatic segmentation of IVUS images. At the frame-level, Efficient-UNet showed a high dice similarity coefficient (DSC, 0.93±0.05) and Jaccard index (JI, 0.87±0.08) for lumen segmentation, and demonstrated a high DSC (0.97±0.03) and JI (0.94±0.04) for EEM segmentation. At the vessel-level, there were close correlations between model-derived vs. experts-measured IVUS parameters; minimal lumen image area (r=0.92), EEM area (r=0.88), lumen volume (r=0.99) and plaque volume (r=0.95). The agreement between model-derived vs. expert-measured minimal lumen area was similarly excellent compared to the experts' agreement. The model-based lumen and EEM segmentation for a 20-mm lesion segment required 13.2 seconds, whereas manual segmentation with a 0.2-mm interval by an expert took 187.5 minutes on average. The deep learning models can accurately and quickly delineate vascular geometry. The artificial intelligence-based methodology may support clinicians' decision-making by real-time application in the catheterization laboratory.

Development and Validation of a Bioanalytical Method for Estimating Ellagic Acid in Wistar Rat Plasma by RP-HPLC Using a Gradient Elution Technique

Abstract Background: Ellagic acid (EA) is a natural polyphenolic compound recognized for bioactive and pharmacologic properties that is found abundantly in various plant groups, particularly eudicotyledons. In the current study a novel, reliable, and cost-effective bioanalytical method was developed for quantifying EA in Wistar rat plasma using RP-HPLC. Methods: Zorbax SB C18 (5μ, 4.6150 mm) and Ascentis C18 (5μ, 1004.6 mm) columns were used in the stationary phase, while the mobile phase consisted of water with 0.1 % formic acid (A) and acetonitrile (ACN) with 0.08% formic acid (B). Results: Optimized parameters were as follows: temperature, 30°C; flow rate, 1.0 ml/min; and PDA detectors, 254 nm. The method exhibited high linearity (r2 = 0.9993) between 5 and 300 μg/ml. Precision, both intra- and inter-day, was within acceptable limits (relative standard deviation &lt;2%), and the mean recovery was 99.73%. The LOD and LOQ were 1.564 ± 0.026 μg/ml and 5.015 ± 0.025 μg/ml, respectively. Stability tests, including short- and long-term evaluations, demonstrated stability under various conditions. Conclusion: The developed method met the necessary criteria and holds promise for application in clinical laboratories for assessing EA levels, either alone or with analytes.

Facile fabrication of a graphene-based chemical sensor with ultrasensitivity for nitrobenzene.

Chemical sensors have a wide range of applications in a variety of industries, particularly for sensing volatile organic compounds. This work demonstrates the fabrication of a chemical sensor based on graphene deposited on Cu foils using low-pressure chemical vapor deposition, following its transfer on oxidized silicon through a wet etching method. Scanning electron microscopy, Raman spectroscopy and UV-vis spectroscopy of the transferred graphene were performed. A device was fabricated by simply connecting the strips of a Cu tape along the two opposite edges of graphene, which acted as a chemical sensor. The sensor was exposed to different analytes, namely acetone, propanol, benzyl chloride, nitrobenzene, carbon tetrachloride and acetic acid. A relative change in the resistance of the device was observed, which was attributed to the interaction of analytes with graphene as it changes charge concentrations in the graphene lattice. The fabricated sensor showed a notable sensitivity and response time for all analytes, particularly a sensitivity as high as 231.1 for nitrobenzene and a response time as short as 6.9 s for benzyl chloride. The sensor was also tested for analyte leakage from containers for domestic, laboratory and industrial applications.

Asymmetric Rowland circle geometries for spherically bent crystal analyzers in laboratory and synchrotron applications

We show that asymmetric operation of spherically bent crystal analyzers is an underutilized opportunity that can improve x-ray spectrometer performance and user operations in both the laboratory and synchrotron environments.

Meeting the moment: Reducing methane emissions and the need for better diagnostics

Methane has over 80 times the greenhouse gas warming potential of carbon dioxide in the short term (i.e., 20-year timeframe). As a consequence, reducing methane emissions can have significant and rapid impact towards reducing climate change. Several categories of anthropogenic sources contribute to methane emissions including the oil and gas industry, coal and other extractive mining, agricultural production, and landfills. Recent atmospheric mapping efforts are identifying and quantifying sources of methane – highlighting the need for improved technologies and processes to reduce methane emissions, and national policies are incentivizing mitigating methane emissions. The urgent and timely need to address the challenge of methane emissions motivates the development of improved diagnostics for laboratory and field applications. This paper describes the context of methane emissions (e.g., sources, concentrations and key transients) with an emphasis on flares and the opportunity for next-generation diagnostics to address the challenges and global need for accurate methane measurements in diverse applications. In particular, trends in prior field-scale flare measurements are presented including effects of cross-wind and heating value on flare combustion efficiency and hydrocarbon removal efficiency. Prior results show the effectiveness of flares at many operating conditions, and conditions where flare performance can be improved. The challenges and need to improve and expand flare emissions measurements are particularly highlighted.

PoCOsteo: generic novel platform for bone turnover marker measurement & monitoring.

Despite the increasing efforts in improving bone health assessments, current diagnostics suffer from critical shortcomings. The present article therefore describes a multiplex label-free immunosensor designed and validated for the assessment of two bone turnover markers (BTMs), namely beta isomerized C-terminal telopeptide of type I collagen (CTx) and Procollagen I Intact N-Terminal (PINP), the combination of which is needed to illustrate an accurate overview of bone health. The immunosensor was then tested outside and inside of a microsystem, with the aim of becoming compatible with a point of care system fabricated for automated assessment of these biomarkers later-on at patient side. Custom-made monoclonal antibodies were specifically designed for this purpose in order to guarantee the selectivity of the immunosensor. In the final platform, a finger prick blood sample is introduced into the microfluidic manifolds without any need for sample preparation step, making the tool suitable for near patient and outside of the central laboratory applications. The platform was exploited in 30 real blood samples with the results validated using electrochemiluminescence immunoassay. The results revealed the platform was capable of measuring the target analyte with high sensitivity and beyond the recommended clinical reference range for each biomarker (CTx: 104-1028 ng L-1 and PINP: 16-96 μg L-1, correspondingly). They also showed the platform to have a limit of detection of 15 (ng L-1) and 0.66 (μg L-1), a limit of quantification of 49 (ng L-1) and 2.21 (μg L-1), and an inter- and intra-assay coefficient of variance of 5.39-6.97% and 6.81-5.37%, for CTx and PINP respectively, which is comparable with the gold standard. The main advantage of the platform over the state-of-the art was the capability of providing the results for two markers recommended for assessing bone health within 15 minutes and without the need for skilled personnel or costly infrastructure.

Sensitive detection of genetically modified maize based on a CRISPR/Cas12a system.

With the vigorous development of biotechnology, genetically modified organisms (GMOs) have become more and more common. In order to effectively supervise and administrate them, the rapid and accurate detection of GMOs is urgently demanded. Here, GMO gene-specific sensing methods based on colorimetry and surface-enhanced Raman scattering (SERS) were proposed based on the lateral branch cleavage function of the CRISPR/Cas12a system. Two transgenes, pCaMV35S and M810 Cry1Ab, were chosen as targets for transgenic crops. By using these methods, we performed transgenic detection on five types of maize leaves and successfully distinguished transgenic from non-transgenic samples. The colorimetric method is rapid, economical and available for field detection. The SERS approach, giving a higher sensitivity to 100 fM, is more suitable for laboratory application scenarios. This study explores practical transgenic detection approaches and will be valuable for the supervision of GMOs.

Eco-friendly novel deconvoluted synchronous spectrofluorimetric approach for the determination of favipiravir, levodropropizine and moxifloxacin hydrochloride as an effective therapeutic combination for COVID-19; application in laboratory prepared mixtures and spiked human plasma

In this work, a green, fast, and simple synchronous spectrofluorimetric approach has been developed to simultaneously determine favipiravir, levodropropizine, and moxifloxacin hydrochloride as co-administered medications for COVID-19 treatment in pure form and spiked human plasma. The synchronous fluorescence spectroscopy technique to analyze the studied drugs at Δλ = 110 nm enabled the determination of levodropropizine at 360 nm. Then, applying Fourier Self-Deconvolution to each spectra to measure favipiravir and moxifloxacin hydrochloride at peak amplitudes of 431 nm and 479 nm, respectively, without any interference. Favipiravir, levodropropizine, and moxifloxacin hydrochloride could be sensitively determined using the described approach over concentration ranges of 20–300 ng/mL, 10–600 ng/mL, and 50–500 ng/mL, respectively. The method's validation was carried out effectively in accordance with guidelines recommended by the ICH. Finally, the Eco-scale and Green Analytical Procedure Index (GAPI) techniques have been used to evaluate the greenness of the proposed method.

Glucosodiene Polymer: A Novel Chemical Structure and Promising Cancer Targeting Agent Exploiting its Metabolic Activity

Glucosodiene, a novel compound synthesized through the reaction between dextrose and sodium bicarbonate, is explored in this study. The main objective was to investigate its potential as a cancer-targeting agent by inhibiting glucose metabolism within tumors, also known as the Warburg effect. Previous studies have demonstrated its impact and safety in laboratory and human applications. However, the chemical and stereochemical formula of glucosodiene has not been confirmed. In this manuscript, we present the NMR and LC-MS results of the synthesized glucosodiene Polymer and describe the optimized method for its preparation. The reaction between dextrose and sodium bicarbonate resulted in the formation of glucosodiene, a Polymer compound with a similar structure to glucose. The NMR analysis confirmed the presence of the formula C12H22O11, while LC-MS results validated its identity as 1-2-O-β-D-Glucopyranosy l-α-D-glucose. Glucosodiene is composed of monomers derived from glucose isomers connected through 1-2 linkages, represented as (1-2-O-β-D-Glucopyranosyl-α-D-glucose). The monomer’s molecular mass is determined to be 178.9, and it shares structural similarities with trehalose but forms the polymer through self-association, resembling the molecular structure of sophorose.

Virtual Reality Based Hypermedia Training for Teachers of MAN 2 Model Makassar

This Community Service Activity (PKM) aims to; (1) provide an introduction to teachers at MAN 2 Model Makassar regarding Virtual Reality learning media as an alternative IT-based learning media, and (2) train MAN 2 Model Makassar teachers to be able to utilize Virtual Reality-based learning media. The methods applied in this service program are the presentation method, the demonstration method, and the practical method. The presentation method is applied in the introduction of hypermedia software using the millers lab application, its benefits, and its application in making virtual reality-based media, demonstration methods regarding program operations and practical methods where teachers practice directly making learning media according to their respective subjects with the use of media-based virtual reality

Sanal Laboratuvarların Fen Eğitiminde Kullanımıyla İlgili 2013-2022 Yılları Arasındaki Çalışmaların İncelenmesi

This study is a systematic review that is composed of the analysis of several international studies on the use of virtual laboratories in science education that were selected based on certain criteria. Research data have been attained by reviewing studies that concern virtual laboratories. For this systematic review, 1322 scientific articles published in the Web of Science database between 2013 and 2022, with the keyword "virtual laboratory" in their titles or abstracts, were reviewed. An article review form was used as the tool for collecting data. In determining the papers to be included in the study, the criterion sampling method was used. The sample of the study consists of 30 papers which comply with the inclusion criteria and were accessible in full text. Descriptive and content analyses were used in this systematic review. The studies on virtual laboratories are presented via descriptive analysis on the basis of their distribution by years, distribution by subject fields, distribution by participant levels, distribution by group sizes, methods and patterns, data collection tools, and frequencies of data analysis types. The results of virtual laboratories that these studies acquired were grouped via content analysis under codes, categories, and themes. When the results achieved by these studies are evaluated as a whole, it becomes clear that virtual laboratory applications positively impact science education with respect to different variables.