Instrumentation Requirements Research Articles

On the Ar I 419.8 nm/751.5 nm (3p5/2p5) line intensity ratio for electric field measurement in dielectric barrier discharge in argon at atmospheric pressure

Abstract Ar I 419.8 nm/751.5 nm line intensity ratio is suggested as a measure of the electric field in atmospheric pressure dielectric barrier discharges in argon. Using the electron distribution function calculated from the Boltzmann equation, electron impact excitation cross sections, quenching coefficients and other atomic data, theoretical dependencies of several line intensity ratios constructed from Ar I 3p5 4p and 3p5 5p argon lines on the electric field were calculated. Among them, the intensity ratio of 5p line at 419.8 nm (1s4–3p5 in Paschen notation) to 4p line at 751.5 nm line (1s4-2p5) was found to be sensitive in both the theory and the experiment.

The suggested line ratio was applied to the study of an atmospheric pressure volume dielectric barrier discharge in pure argon with sinusoidal voltage excitation. The spatiotemporal distribution of light emissions on 4p and 5p lines was measured using the time-correlated single photon counting technique (TCSPC) with high temporal (180 ps) and spatial (25 μm) resolution. The light emission on 419.8 nm line indicated the high electric field region in the propagating cathode-directed streamer due to a high excitation energy (14.58 eV) and a short effective lifetime (150 ps) of the 3p5 level. 

Several measured and calculated electron impact excitation cross sections were examined to interpret the measured line intensity ratio. Using the calculation based on a combination of the calculated (Zatsarinny 2014) and the measured cross section (Boffard 2007) for 2p5 and 3p5 levels, the electric field strengths reaching 110–120 Td were measured in the streamer head. 

The assumptions and limitations of this approach, as well as its instrumentation requirements, are discussed.

Разработка инструмента оценки эффективности экспериментальной деятельности подростков на примере задач с физическим содержанием

This article focuses on addressing the problem of enhancing the effectiveness of natural science education in schools, particularly in physics, by applying the principle of problem-based learning and designing lessons centered on experimental activity. The foundational unit of this model is a student's action that is motivated, deliberate, and aimed at attempting to solve a task, exploring solutions, and engaging in reflection and generalization of goal-directed actions. However, assessing the effectiveness of such actions requires high-quality research instruments capable of collecting reliable data. To address this challenge, we developed an assessment instrument and empirically tested some psychometric requirements. We hypothesized that the key requirements for such an instrument are: (1) alignment with the structure of activity; (2) multifunctionality and robustness against changes in the evaluator. These requirements were formulated by the authors based on V.V. Davydov's theory of learning activity and the theory of psycho-pedagogical measurement. Data collection was conducted through non-participant observation, with student activity evaluated by independent experts—assessors—using audio and video recordings of experimental lessons in three schools in Yuzhno-Sakhalinsk. The validation of the instrument's requirements was carried out through the analysis of expert judgments and the application of consistency metrics, such as the proportion of matching results and Kendall's nonparametric concordance coefficient. The analysis of the collected data demonstrated that: (a) the developed instrument effectively captures actions related to task-solving in accordance with the theoretical model; (b) the assessments by independent observers yielded similar results, as reflected in acceptable consistency metrics for their evaluations.

EFL TEACHERS' PERCEPTIONS OF AI'S IMPACT ON ACADEMIC INTEGRITY AND PEDAGOGY IN BANGLADESHI UNIVERSITIES

The objectives of the research are to identify Bangladeshi EFL teachers’ perceptions regarding the role of AI in language teaching in the way it affects academic integrity, the pedagogical issues, and how these can affect the efficacy of the existing institutional policies in English teaching profession. This study used a descriptive quantitative research design, which is based on an online questionnaire survey with 115 EFL teachers teaching in 22 private universities in Bangladesh. The results found that 69.6% of teachers were concerned about the ethical implications of AI, most prominently 69.6% about the alignment with academic dishonesty. In addition, 65.2% of the teachers revealed challenges in merging AI into class pedagogy, with the foremost reason being a lack of institutional support and training provision to integrate the lessons into class lessons. Indicatively, 74.8% of respondents stated that current institutional policies do not enable dealing with the challenges posed by AI in education. The study recommends the immediate requirements for extensive AI-related training programs, institutional regulations, and instruments to attain academic integrity in EFL classrooms. This research builds on and adds to the growing literature on AI in education while capturing the Bangladeshi EFL context. Future research can be conducted on the threats of AI-integration in EFL teaching and learning.

Operational considerations for approximating molecular assembly by Fourier transform mass spectrometry

Some of the most common life detection techniques for planetary exploration focus on organic molecule characterization, but life on other planets may not chemically resemble that found on Earth. Therefore, an agnostic detection system of signs of life (biosignatures) is essential. Assembly Theory (AT) is a conceptual tool for understanding evolution and object formation that has been useful in developing an approach to quantify molecular complexity via the Molecular Assembly index, which when combined with abundance, allows the total assembly number of a sample to be calculated. Because AT makes no assumptions about the chemistry of life, it is an agnostic tool that identifies molecular structures that are probabilistically more likely to have arisen via selection and therefore biological processes. AT uses graph theory to quantify molecular complexity by finding the shortest sequence of joining operations (e.g., chemical bonds) required to build a compound from a set of starting materials allowing recursive reuse of units or fragments. For molecules, this number of steps is the MA value. We explore the use of Fourier transform (i.e., Orbitrap) mass spectrometry for approximating MA by quantifying how a molecule breaks apart into fragments. We analyze amino acid and nucleoside standards individually and as mixtures, as well as amino acids from naturally occurring biological and meteoritic sources. Aside from sample type, we evaluate the effect of analyte concentration and fragmentation energies on the generated MA value. Additionally, an older Orbitrap model similar to flight prototype instrumentation, was tested. The raw mass spectrometry data was compared with two different MA processing algorithms - one that uses the parent molecule spectrum and molecular weight (recursive) and one that does not (non-recursive). Concentration, fragmentation energy, and sample type all influence the raw mass spectra. However, the recursive algorithm reports MA estimates that are more consistent across sample types, concentrations, and fragmentation energies. We discuss instrument requirements for approximating MA that can be applied to future flight and sample return missions.

Standardized surgical procedure for natural orifice specimen extraction surgery of precision functional sphincter-preserving surgery for ultra-low rectal cancer (NOSES-PPS) (2024 edition)

Natural orifice specimen extraction surgery of precision functional sphincter- preserving surgery for ultra-low rectal cancer (NOSES-PPS) is an innovative surgical technique that builds upon traditional laparoscopic surgery for low rectal cancer. This method utilizes a specially designed transparent screw-thread anal dilator and associated equipment to achieve precise tumor localization and resection through direct visualization via the anus. Digestive tract reconstruction is then accomplished using a combination of a precision circular stapler and manual suturing, thereby preserving sphincter function in patients with ultra-low rectal cancer. NOSES-PPS has been widely adopted across multiple provinces and cities in China, with over 500 cases successfully performed to date. The technique and its outcomes have been published in both national and international peer-reviewed journals, receiving significant recognition from the medical community. However, as a novel approach to rectal cancer surgery, there is currently a lack of authoritative clinical practice guidelines detailing the specific procedural steps of NOSES-PPS. To address this gap, the Colorectal Tumor Committee of the Chinese Medical Association, the Colorectal Cancer Committee of the Chinese Anti-cancer Association, and the China NOSES Collaborative Group have jointly led an effort to establish standardized guidelines for NOSES-PPS. This initiative involved the collaboration of experts in colorectal oncology from numerous large medical centers across China. Through multiple rounds of consultation and discussion, these experts have developed a comprehensive set of guidelines that detail the definition of NOSES-PPS, requirements for instrumentation, indications, key operative techniques, and the management of perioperative and postoperative complications. This guideline aims to promote the standardized implementation of NOSES-PPS in clinical practice.

Heat of reaction in individual metabolic pathways of yeast determined by mechanistic modeling in an insulated bioreactor

BackgroundThe yeast Saccharomyces cerevisiae, commonly used in industry, exhibits complex metabolism due to the Crabtree effect, fermenting alcohol even under aerobic conditions when glucose exceeds 0.10-0.15 g/L. The heat released by the biological activity is a signal very easy to collect, given the minimal instrumentation requirements. However, this heat depends on the activated metabolic pathways and provides only an indirect indicator, that cannot be used in a simple way. This study demonstrated the potential of a mechanistic model to control the process by measuring the heat released by the biological activity.ResultsThe complexity arising from coexisting metabolic pathways was addressed by a comprehensive model of Saccharomyces cerevisiae together with the heat of reaction included in a rigorous enthalpy balance of the bioreactor. Batch cultures were performed in an insulated bioreactor to trigger a temperature signal. The heat of individual metabolic pathways was determined by inverse analysis of these tests using Particle Swarm Optimization (PSO): -101.28 ±0.02kJ/mol for anaerobic fermentation, -231.27±0.06kJ/mol for aerobic fermentation, and -662.94 ± 0.54kJ/mol for ethanol respiration. Finally, the model was successfully applied and validated for online training under different operating conditions.ConclusionsThe model demonstrates remarkable accuracy, with a mean relative error under 0.38% in temperature predictions for both anaerobic and aerobic conditions. The viscous dissipation is a key parameter specific to the bioreactor and the growth conditions. However, we demonstrated that this parameter could be fitted accurately from the early stages of the experiment for further prediction of the remaining part. This model introduces temperature, or the thermal power required to maintain temperature, as a measurable parameter for online feedback model training to provide increasingly precise feed-forward control.Graphical

Application of quality by design in the development of HPTLC Method for the estimation of ceritinib in bulk and synthetic mixture

The aim of the present work is to develop and validate the High-Performance Thin Layar Chromatography method for the estimation of Ceritinib in bulk and synthetic mixture using the Analytical Quality by Design (AQbD) approach as per ICH Q8 (R2). The AQbD is used to develop a precise HPTLC method. The AQbD parameter elements like QTMP (Quality Target Method Profile- Ceritinib, method type, instrument requirement, sample characteristics, synthetic mixture preparation) CMA—Critical method attributes (chloroform ± 1 ml, methanol ± 1 ml, triethylamine ± 0.05), and Risk assessment (the Ishikawa (fishbone) diagram) were carried out for the development of the HPTLC method for Cerinitib. The Box-Behnken design was utilized for the optimization of chromatographic conditions in HPTLC. The method utilized an aluminum HPTLC plate pre-coated with silica gel G60 F254 as a stationary phase along with chloroform: methanol: triethylamine (8.9: 1.6: 0.07 v/v/v) as a mobile phase. ANOVA results and perturbation plot indicates that methanol and triethylamine had more impact than chloroform on the retardation factor. The retardation factor was found to be 0.37. The absorbance mode at 277 nm was used for the densitometric study. It was found that the linearity ranged from 20 to 100 ng/band, with a correlation coefficient of 0.998. No interference was observed from excipients and mobile phase solvents. The results indicate that the AQbD approach is effectively applied to optimize the retardation factor and the method is appropriate for routine laboratory analysis.

Reference frequency variance-based rapid identification method for vortex flow rate under mixed vibration interference

Pipeline systems in industrial applications may encounter strong mixed vibration interference, resulting in measurement errors of vortex flowmeters. Current research primarily addresses single types of vibration interference. Various signals output by vortex flow sensors under diverse operating conditions were analyzed to tackle the issue of mixed vibration interference. The amplitude and frequency characteristics of transient impact-type interferences were studied. The differences in frequency fluctuations between periodic interferences and periodic signals were investigated. Then, a method based on reference frequency variance was proposed to resist mixed vibration interference. The primary calculation load of this method arises from the execution of Fast Fourier Transform (FFT). To meet the instrument requirements of low-power consumption and real-time performance, a multipoint FFT method based on a low-power accelerator built-in microcontroller was proposed, which remarkably improved the calculation speed of multipoint FFT and conserved storage space. The reference frequency variance-based antimixed vibration interference algorithm was implemented in real time using a low-power vortex flowmeter system developed by our team, and an antimixed vibration interference gas flow verification experiment was conducted. The method can accurately identify vortex flow signals when the interference energy of the periodic type and the main mode energy of the transient impact surpasses the energy of the flow signal.

Pengaruh Disiplin Kerja, Kompensasi, Motivasi Kerja Terhadap Kinerja Karyawan pada Solo Techno Park Surakarta

This study examines how work discipline, compensation, and motivation affect employee performance at Solo Techno Park in Solo, Indonesia. The study used a purposive sampling technique with a sample size of 96 people. It targets all employees. Data were collected quantitatively using techniques such as Instrument Requirements Test, Classical Assumption Test, and Hypothesis Test using SPSS. The results show that work discipline significantly improves performance, with a t-test value of 3.861 and a p-value of 0.000 indicating a strong correlation. Compensation also has a positive impact on performance, with a t-test value of 2.160 and a p-value of 0.033. However, with a t-test value of 18.053 and a p-value of 0.000, work motivation turned out to be the most important, with 83% of the variation in employee performance. Regression analysis shows that these three factors are responsible for 83% of the variation in employee performance, indicating that employees must be disciplined, fairly rewarded, and motivated to achieve optimal results.

Advancements in Key Technologies for Vibration Isolators Utilizing Electromagnetic Levitation

With the advancement of manufacturing, the precision requirements for various high-precision processing equipment and instruments have further increased. Due to its noncontact nature, simple structure, and controllable performance, electromagnetic levitation has broad application prospects in ultra-precision instruments and ground testing of aerospace equipment. Research on vibration isolation technology using electromagnetic levitation is imperative. This paper reviews the latest research achievements of three types of passive isolators and five active isolation actuators. It also summarizes the current research status of analytical methods for passive isolators and the impact of isolator layout. This study explores current isolators’ achievements, such as the development of passive isolators that generate negative stiffness and require mechanical springs for uniaxial translational vibrations, single-function actuators, and control systems focused on position and motion vibration control. Based on the current isolators’ characteristics, this review highlights future developments, including focusing on passive isolators for heavy loads and multi-axis isolation, addressing complex vibrations, including rotational ones, and developing methods to calculate forces and torques for arbitrary six-DOF movements while improving speed. Additionally, it emphasizes the importance of multifunctional actuators to simplify system structures and comprehensive control systems that consider more environmental factors. This provides significant reference value for vibration isolation technology using electromagnetic levitation.

A polydiacetylene (PDA)-based colorimetric sensor for on-site cyanide anion monitoring integrated with a lateral flow assay platform

An advanced sensing platform for the on-site and real-time monitoring of cyanide (CN−) pollution was developed, addressing the key challenges of enhancing the selectivity and sensitivity, whilst simplifying the sensing process. This platform features a novel colorimetric sensor (PDA-BMN) created by incorporating a receptor for CN− recognition within a polydiacetylene (PDA) conjugated polymer system. The interaction of CN− with the receptor distorted the π-conjugated backbone, causing a distinct color change from blue to orange, with a limit of detection (LOD) of 0.55 µM, thereby highlighting its high sensitivity. The PDA-BMN system was integrated into a lateral flow assay (LFA) strip to facilitate on-site monitoring. The LFA strip was strategically designed with a partially pressed zone to reduce the fluid flow rate, enhance the reaction time, and increase the probability of interaction with the PDA-BMN sensor. This innovation resulted in a significant colorimetric transition, enabling the rapid and sensitive detection of CN− without the requirement for analytical instruments. This study demonstrates the effectiveness of combining PDA and LFA systems for real-time environmental monitoring, offering a robust, efficient, and user-friendly solution for detecting CN− pollution.

Surveillance of human adenoviruses in water environments: Assessing the suitability of a locally developed quenching of unincorporated amplification signal reporters-loop-mediated isothermal amplification assay

The human adenovirus (HAdV) has shown greater environmental persistence, more water treatment resistance than bacteria, and cause infection even at low concentrations. HAdV causes gastrointestinal illnesses and is abundant in various environmental samples such as groundwater, surface water, recreational water, and drinking water. The detection of these pathogens calls for a more practical and affordable approach. A recent technology based on the quenching of unincorporated amplification signal reporters (QUASR) was adapted for the detection of human adenoviruses. This technology allows for non-inhibitory, single-step DNA detection in a closed tube. The QUASR-(loop-mediated isothermal amplification (LAMP) assay was previously optimized and was tested for its applicability to detect enteric HAdV in two areas where people can unintentionally be exposed to contaminated water. A total of 203 water samples were collected and tested using both real-time PCR and QUASR-LAMP assays. Results showed a higher positivity rate of 78.82 % (160/203) for QUASR-LAMP compared to qPCR with only 58.62 % (119/203). The sensitivity and specificity rates for QUASR-LAMP were calculated at 86.55 % and 32.14 %, respectively, when compared to qPCR. The QUASR-LAMP assay's ability to detect target analytes even at low concentrations can be attributed to its increased diagnostic sensitivity but lower specificity since there were samples that were positive in PCR but negative in the QUASR-LAMP assay. However, this characteristic does not diminish its utility as a valuable tool for the detection of HAdV. In fact, this attribute enhances its advantages in situations with constrained space and instrumentation requirements, making it suitable for rapid surveillance of important viruses. Finally, the capacity of the QUASR-LAMP assay to differentiate between positive and negative samples at a defined endpoint is highly beneficial for laboratory technicians who possess limited molecular biology expertise or experience. The QUASR-LAMP platform has demonstrated its usefulness as a diagnostic tool for surveillance of enteric adenoviruses in water sources.

Practical considerations for assessing crew noise exposure in armored vehicles.

Measurement and analysis of the continuous and intermittent noise produced by armored vehicle (AV) platforms, including the output from communications systems as experienced by crew, are necessary for the purposes of exposure prediction, to support the selection of hearing protection and communication devices, and to facilitate assessments of compliance with occupational health and safety legislation. Practical estimation of the personal noise exposure of AV crews requires the assessment of the vehicle, communications and special-to-role activity noise sources, and an understanding of how these sources combine. Procedures are described that consider instrumentation requirements, AV configuration and build standard, operating conditions representative of actual use, the application of speed thresholding to measurements, and derivation of communications noise levels. Real-world examples are given where these procedures have been applied to an in-service tracked AV to estimate crew noise exposure. The procedures and methods presented are a compromise between precision, repeatability, reproducibility, and pragmatism. Measurements of AV noise are expected to be obtained during the commissioning stage of vehicle design, immediately prior to the vehicle being put into operational service and following any major modifications to the vehicle to inform the necessary engineering, administrative, and personal protective equipment control measures.

Application of Loop-Mediated Isothermal Amplification in Plant Pathogen Detection.

Plant diseases impact the production of all kinds of crops, resulting in significant economic losses worldwide. Timely and accurate detection of plant pathogens is crucial for surveillance and management of plant diseases. In recent years, loop-mediated isothermal amplification (LAMP) has become a popular method for pathogen detection and disease diagnosis due to the advantages of its simple instrument requirement and constant reaction temperature. In this review, we provide an overview of current research on LAMP, including the reaction system, design of primers, selection of target regions, visualization of amplicons, and application of LAMP on the detection of all major groups of plant pathogens. We also discuss plant pathogens for which LAMP is yet to be developed, potential improvements of plant disease diagnosis, and disadvantages that need to be considered.

Programmed DNA tile response system enabled accurate detection of ATP for clinical diagnosis

Adenosine triphosphate (ATP), as a crucial signaling molecule, is of high potential diagnosis value for multiple diseases. However, current technologies for ATP detection struggle to satisfy the harsh conditions required for biospecimen tests, existing several limitations for clinical practical application. In this study, the DNA tile response system was designed and constructed by integrating nucleic acid aptamer, hybrid chain reaction (HCR), and DNA tile self-assembly technology to achieve accurate detection of ATP in body fluid specimens. The DNA tile response system, possessing high-order structure characteristic, could remove HCR false-positive products and conquer the high noise background to enhance the detection sensitivity. Under the optimal reaction parameters, this system achieved the low limit of detection (LOD) of 189.23 nM over a wide linear range and splendid detection specificity faced with multiple interference terms. Furthermore, this system, possessing simple storage conditions, long-term detection stability, and superior anti-interference performance, was sufficient to satisfy the detection requirements for complicated biological specimens in multi-scenarios. Ultimately, the DNA tile response system showed excellent diagnostic efficiency that could easily distinguish urinary tract infection patients and healthy controls through ATP quantification, as well as hypertension patients and healthy ones. This system provides a high-potential rapid detection tool for early diagnosis and dynamic monitoring of urinary tract infections and hypertension, holding enormous potential for clinical translation due to the superiorities of simple operation, general applicability, and low instrument requirements.

Vision-based reinforcement learning control of soft robot manipulators

PurposeThis study aims to tackle control challenges in soft robots by proposing a visually-guided reinforcement learning approach. Precise tip trajectory tracking is achieved for a soft arm manipulator.Design/methodology/approachA closed-loop control strategy uses deep learning-powered perception and model-free reinforcement learning. Visual feedback detects the arm’s tip while efficient policy search is conducted via interactive sample collection.FindingsPhysical experiments demonstrate a soft arm successfully transporting objects by learning coordinated actuation policies guided by visual observations, without analytical models.Research limitations/implicationsConstraints potentially include simulator gaps and dynamical variations. Future work will focus on enhancing adaptation capabilities.Practical implicationsBy eliminating assumptions on precise analytical models or instrumentation requirements, the proposed data-driven framework offers a practical solution for real-world control challenges in soft systems.Originality/valueThis research provides an effective methodology integrating robust machine perception and learning for intelligent autonomous control of soft robots with complex morphologies.

High-precision temperature control of helium Joule–Thomson cryocooler: Long-term temperature stability

To meet the refrigeration requirements of scientific instruments for mK-level temperature stability over a long-time range in the liquid helium temperature, the temperature characteristics and high-precision control strategies of the helium Joule-Thomson cryocooler (JTC) have been experimentally investigated for the first time. Based on the Ideal Gas Law, the influencing mechanism of pre-cooling temperature, gas reservoir volume, and liquid phase volume fraction on refrigeration temperature were qualitatively analyzed and experimentally verified. An active control studies of pre-cooling temperature, low-pressure and heat load were carried out to verify the feasibility of active temperature control of helium JTC. Finally, a long-term temperature stability of ±1 mK/h was successfully achieved when a multi-stage active control strategy was adopted, which is the optimal long-term temperature stability of helium JTC that have been reported to date.

Recombinase-aided amplification assay for rapid detection of imipenem-resistant Pseudomonas aeruginosa and rifampin-resistant Pseudomonas aeruginosa.

The indiscriminate use of antibiotics has resulted in a growing resistance to drugs in Pseudomonas aeruginosa. The identification of antibiotic resistance genes holds considerable clinical significance for prompt diagnosis. In this study, we established and optimized a Recombinase-Aided Amplification (RAA) assay to detect two genes associated with drug resistance, oprD and arr, in 101 clinically collected P. aeruginosa isolates. Through screening for the detection or absence of oprD and arr, the results showed that there were 52 Imipenem-resistant P. aeruginosa (IRPA) strains and 23 Rifampin-resistant P. aeruginosa (RRPA) strains. This method demonstrated excellent detection performance even when the sample concentration is 10 copies/μL at isothermal conditions and the results could be obtained within 20 minutes. The detection results were in accordance with the results of conventional PCR and Real-time PCR. The detection outcomes of the arr gene were consistently with the resistance spectrum. However, the antimicrobial susceptibility results revealed that 65 strains were resistant to imipenem, while 49 strains sensitive to imipenem with oprD were identified. This discrepancy could be attributed to genetic mutations. In summary, the RAA has higher sensitivity, shorter time, and lower-cost instrument requirements than traditional detection methods. In addition, to analyze the epidemiological characteristics of the aforementioned drug-resistant strains, we conducted Multilocus Sequence Typing (MLST), virulence gene, and antimicrobial susceptibility testing. MLST analysis showed a strong correlation between the sequence types ST-1639, ST-639, ST-184 and IRPA, while ST-261 was the main subtype of RRPA. It was observed that these drug-resistant strains all possess five or more virulence genes, among which exoS and exoU do not coexist, and they are all multidrug-resistant strains. The non-coexistence of exoU and exoS in P.aeruginosa is related to various factors including bacterial regulatory mechanisms and pathogenic mechanisms. This indicates that the relationship between the presence of virulence genes and the severity of patient infection is worthy of attention. In conclusion, we have developed a rapid and efficient RAA (Recombinase-Aided Amplification) detection method that offers significant advantages in terms of speed, simplicity, and cost-effectiveness (especially in time and equipment aspect). This novel approach is designed to meet the demands of clinical diagnostics.

Optimizing Conditions of Polyethylene Glycol Precipitation for Exosomes Isolation From MSCs Culture Media for Regenerative Treatment.

Mesenchymal stem cell (MSC)-derived exosomes, as a cell-free alternative to MSCs, offer enhanced safety and significant potential in regenerative medicine. However, isolating these exosomes poses a challenge, complicating their broader application. Commonly used methods like ultracentrifugation (UC) and tangential flow filtration are often impractical due to the requirement for costly instruments and ultrafiltration membranes. Additionally, the high cost of commercial kits limits their use in processing large sample volumes. Polyethylene glycol (PEG) precipitation offers a more convenient and cost-effective alternative, but there is a critical need for optimized and standardized isolation protocols using PEG precipitation across different cell types and fluids to ensure consistent quality and yield. In this work, we optimized the PEG precipitation method for exosomes isolation and compared its effectiveness to two commonly used methods: UC and commercial exosome isolation kits (ExoQuick). The recovery rate of the optimized PEG method (about 61.74%) was comparable to that of the commercial ExoQuick kit (about 62.19%), which was significantly higher than UC (about 45.80%). Exosome cargo analysis validated no significant differences in miRNA and protein profiles associated with the proliferation and migration of exosomes isolated by UC and PEG precipitation, which was confirmed by gap closure and CCK8 assays. These findings suggest that PEG-based exosomes isolation could be a highly efficient and high-quality method and may facilitate the development of exosome-based therapies for regenerative medicine.

Point-of-care CRISPR-based Diagnostics with Premixed and Freeze-dried Reagents.

Molecular diagnostics by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based detection have high diagnostic accuracy and attributes that are suitable for use at point-of-care settings such as fast turnaround times for results, convenient simple readouts, and no requirement of complicated instruments. However, the reactions can be cumbersome to perform at the point of care due to their many components and manual handling steps. Herein, we provide a step-by-step, optimized protocol for the robust detection of disease pathogens and genetic markers with recombinase-based isothermal amplification and CRISPR-based reagents, which are premixed and then freeze-dried in easily stored and ready-to-use formats. Premixed, freeze-dried reagents can be rehydrated for immediate use and retain high amplification and detection efficiencies. We also provide a troubleshooting guide for commonly found problems upon preparing and using premixed, freeze-dried reagents for CRISPR-based diagnostics, to make the detection platform more accessible to the wider diagnostic/genetic testing communities.