Analytical Test Research Articles

Dissipative tie-rods restraining one-sided rocking masonry walls: analytical formulation and experimental tests

Dissipative tie-rods restraining one-sided rocking masonry walls: analytical formulation and experimental tests

Analysis of Expectations in Routine Appointments: A Cross-Sectional Study in Portugal

Preventive medicine is a subject of study due to the increasing evidence that it can cause more harm than good, and the population's interest in routine appointments is widely recognized. The main objective of this study was to understand users' expectations regarding routine appointments in primary health care and compare them to doctors' perceptions regarding these expectations. We carried out a cross-sectional observational study in 2023 through the application of two questionnaires: one for adult patients and another for family physicians. The invitations to answer the questionnaire via Google Forms were shared on specific social networks. For elderly patients, the questionnaire was conducted in-person by one of the researchers. It consisted of 25 questions about preventive attitudes during appointments, analytical tests and their frequency, and recommendations based on sex and age, differing in the language used. A sample of 225 patients and 100 general and family medicine doctors was obtained. The patients selected an average of 7.8 ± 9.7 preventive attitudes during the consultation, and the doctors judged that they would have selected 4.6 ± 2.9 (p = 0.001). Cardiac and pulmonary auscultation (82.6%), physical exercise quantification (74.7%), and smoking habits assessment (72.9%) were the most selected measures, the most selected tests being blood glucose measurement (81.8%), lipid profile (80.4%), and urine analysis (75.1%). For 68.2% of patients, routine check-ups should be annual, with 88.0% of doctors believing that patients would want this frequency. The socioeconomic level of the population did not significantly influence the results. It is important that general practitioners / family doctors are aware of patients' expectations. In this sample, patients revealed a greater appreciation for a higher number of preventive medical measures during consultations and more periodic analytical testing than thought by the doctors. Doctors also judged that users would show greater interest in the frequent implementation of screening programs.

Preparation and characterisation of zirconia/hydroxyapatite bioactive composites as potential dental implants

In dental implants, zirconia is well-known as a crown material due to its excellent acid and base resistances and appearance close to natural teeth. In addition, its extraordinary mechanical properties render zirconia to be a potential candidate as an implant component of a whole implanted tooth, if its biocompatibility can be improved to promote adhesion to natural hard tissues. This study aims to enhance the bioactivity of zirconia with the aim of improving its integration with gum bone. Hydroxyapatite is the major component of natural bone and is thus selected as the modifier to improve the bioactivity of zirconia. A series of zirconia/hydroxyapatite composites with varied compositions were prepared under different conditions in order to find the optimal composites for the target application. Various analytical technologies and mechanical tests are employed to characterise the structure and properties of resultant composites. Results show that the component ratio and sintering temperature have a significant influence on the composite properties. An increase in hydroxyapatite component tends to enhance bioactivity but decline mechanical strength. Composites containing 10 wt% of hydroxyapatite maintain sufficient mechanical strength under the optimal sintering conditions whilst possessing excellent bioactivity, demonstrating that hydroxyapatite-modified zirconia has the potential as dental implant materials. Sintering results suggest that mechanical strength is obtained at 1400 °C for 2 h for the composite containing 10 wt% of hydroxyapatite.

Traffic noise mitigation through texture-induced quiet pavement: Analytical modeling and field test

Tire-pavement noise is a major contributor to traffic noise pollution, impacting human health and well-being. The advent of 3D printing and prefabrication technologies makes it feasible to economically produce delicate concrete pavement textures for noise mitigation. However, relationships between the noise and texture characteristics (e.g., cavity shape, width, depth, and spacing) remain unknown. This study developed an analytical model for tire-pavement noise and calibrated/validated the model using On-board Sound Intensity tests on a purposely constructed road section with manufactured texture configurations. These textures were found to be capable of reducing the noise level by 8–15 dB(A) over conventional concrete textures, and the model prediction closely matched experimental data. Subsequently, the model was used to investigate the texture-noise relationships and identify those major influencing factors. This study contributes to tire-pavement noise modeling and offers insights for building quieter concrete pavements and enhancing the urban living environment.

The NanoSIMS-HR: The Next Generation of High Spatial Resolution Dynamic SIMS.

The high lateral resolution and sensitivity of the NanoSIMS 50 and 50L series of dynamic SIMS instruments have enabled numerous scientific advances over the past 25 years. Here, we report on the NanoSIMS-HR, the first major upgrade to the series, and analytical tests in a suite of sample types, including an aluminum sample containing silicon crystals, microalgae, and plant roots colonized with a symbiotic fungus. Significant improvements have been made in the Cs+ ion source, high voltage (HV) control, stage reproducibility, and other aspects of the instrument that affect performance. The modified design of the NanoSIMS-HR thermal-ionization Cs+ source enables a 5 pA primary ion beam to be focused into a 100 nm spot, a ∼2.5-fold increase compared to Cs+ sources on previous instruments (∼2 pA at 100 nm). The brightness of the new Cs+ source enables an ultimate lateral resolution as high as 30 nm and improved detection limits for a given analysis area. Sample stage movement accuracy is higher than 500 nm, enabling many-fold higher throughput automated analyses. With the new HV control, the primary ion beam impact energy can be reduced from 16 to 2 keV, which enables higher depth resolution during depth profiling (a 2-fold improvement), albeit with a 5-fold decrease in lateral resolution. In the NanoSIMS-HR, the secondary ion column and detection system are identical to those used in the previous series, and the isotopic analysis performance is as precise as in previous NanoSIMS instruments.

Optimization of sandstone processing waste, electric arc furnace slag, and fly ash-based ternary blended eco-friendly geopolymers.

Over the years, ordinary Portland cement (OPC) has been used to meet growing demands of land and housing facilities arising out of population overburdens. It is well documented that OPCs, besides their outstanding qualities as building materials, are also significant contributors to global greenhouse gases (GHG). Consequently, recent years have noticed an emerging interest in the search for alternatives to Portland cement-based binders. Geopolymers are well-suited to serve this purpose owing to their superior attributes and low CO2 emissions compared to conventional cement. Still, the industrialization of geopolymers has not reached a meaningful value due to the prevailing fundamental barriers involving the requirement of corrosive environments and intensive heat-curing regimes in post-fabrication processes. The current study investigates the viability of using synergistic mixtures based on stone residues, pulverized ash, and steel slags in fabricating geopolymer composites cured at ambient temperature with reduced ingestion of alkalis. A comprehensive assessment of the engineering, mineralogical, and microstructural characteristics was performed in terms of setting times, physico-mechanical, durability, non-destructive, and analytical tests. Further, a scaled-down approach was utilized to evaluate the feasibility of the designed composites as construction entities. The incorporation of SW (10-40%) prolonged the setting periods (~ 150min.) and abridged the engineering properties of the ternary pastes collectively by 127% due to silica coalescences. Besides, replacements of stone residues with FA (20-30%) and EAF (30-60%) improved the blend performance due to Ca and Al assimilations. All the developed composites satisfied the acclamations for OPC grade 33, CEM V class 32.5N, and OPC Type - I suggested by IS, EN, and ASTM standards, respectively, with matrices constituting CASH-CSH-NASH-(N,C)-A-S-H type gelation complexes identified by the X-ray, infrared, and electron imaging spectroscopic analysis. In addition, a cumulative deficit of about 60-90% was observed in energy and carbon footprints relative to OPCs, indicative of the binders' sustainability traits.

Pengaruh Eksperiental Marketing terhadap Minat Beli Ulang: Studi Kasus pada Warung Kopi Tropical Space di Kecamatan Limboto

This study aims to determine how much Experiential Marketing influences Repurchase Interest (tropical space survey customers). The sampling technique used in this study uses probability sampling methods; the number of samples taken in the study uses the Chocran formula, which is 96 respondents rounded up to 100 respondents. The data collection technique in this study uses a questionnaire with a population of students at Gorontalo State University, Gorontalo University, and the Limboto District Community. The analytical test tool used in testing this study is simple linear regression. The data analysis method uses the SPSS 26 application. The results of the study showed that Experiential Marketing significantly influences Repurchase Interest of 0.060, indicating that every one-unit increase in the Experiential Marketing variable will increase Repurchase Interest. Although Experiential Marketing has a significant influence, the coefficient of determination (R2) of 0.102 indicates that only 10.2% of the variation in Repurchase Interest can be explained by Experiential Marketing. This means that 89.8% of the variation in Repurchase Interest is explained by other factors not included in this study. The robust methodology used in this study ensures the credibility of the findings.

Graphene-reinforced titanium coatings deposited by Cold Gas Spray: Study of microstructure, mechanical and wear properties

This study integrates graphene-based nanostructures as reinforcement in a Ti matrix to produce coatings using the Cold Gas Spray (CGS) technique, aiming to enhance mechanical and tribological properties while overcoming some of the limitations of conventional thermal spray methods. The hypothesis holds that incorporating Carbon Nanofibers (GFs) into Ti matrices significantly reinforces these properties compared to pure Ti coatings. The study employed ball milling for the powders obtaining, CGS deposition, and various analytical tests to evaluate the performance of Ti-GFs and pure Ti coatings. Results revealed that Ti-GFs coatings significantly improved in mechanical properties, achieving ultimate tensile strength up to 456 MPa and a strain increase to 2.27%. These improvements are attributed to effective load transfer across the Ti-GFs interfaces, facilitated by strong chemisorption interactions. Additionally, heat treatments at 1000 °C relieved residual stresses and promoted microstructural changes via atomic diffusion, further contributing to the coatings’ strength and ductility. Tribological assessments revealed a 21% reduction in the coefficient of friction for Ti-GFs coatings compared to as-sprayed Ti, though was 2% higher than that of Ti-Bulk. This suggests the potential of graphene as a nanoscale lubricant, though further optimization of GFs dispersion and interface interactions may result in even lower coefficient.These findings highlight the potential of GFs reinforced metal matrix composites applied by CGS for critical applications in sectors such as aerospace and biomedical, which demand materials with high strength and reduced mechanical wear. The study also identifies key areas for future research, including the optimization of graphene dispersion and interface bonding, to fully exploit the benefits of GFs in CGS coatings.

Study of the Mental Health of the Elderly and Related Factors

Background: Aging and increase in the elderly population are the most important issues in recent years in developed countries and some developing countries. Mental health is one of the crucial aspects of elderly well-being and must be addressed to improve community health. This study is conducted to examine the mental health of the elderly and the related factors in Gorgan city, 2022. Methods: The present study is descriptive-analytical and was conducted using a two-stage cluster random sampling method. First, four comprehensive health service centers were selected as a cluster from among the centers of Gorgan city, and then 263 people were randomly selected from the chosen centers, proportionate to the number of registered elderly individuals in the electronic service system. The standard depression questionnaire for the elderly was utilized for assessment. Data were then entered into SPSS software version 18 and with descriptive and analytical statistical tests, including the Mann-Whitney test, Chi-square test, and logistic regression (The significance level was less than 0.05(. Results: A total of 263 elderly people were evaluated with a mean age of 68.64 ± 7.2 . 143 (54.4%) were male and 120 (45.6%) were female. The prevalence of depression was reported to be 27.8. The occurrence of depression was significantly associated with age, marital status, and the presence of underlying disease conditions (p < 0.05). However, gender, place of residence, and BMI did not show a statistically significant relationship with the occurrence of depression. Aging, underlying diseases, and not being married increase the chance of depression in the elderly. Conclusion: Although the prevalence of depression in the elderly is lower than the average of the whole country in this study, they are in a better condition. However, due to the fact that they are a special target group, as well as the various risk factors of the disease, including age, lack of marriage, and the presence of an underlying disease in this group, it is suggested that more appropriate planning be done to improve their mental health status.

Evaluation of combustion system for organically bound tritium analysis using dried fish samples.

The combustion process of the organically bound tritium (OBT) analysis method is difficult and requires sophisticated techniques. For ease, safety, and reproducibility a semi-automatic combustion system was developed. An arbitrary combustion program that prevents sudden ignition was devised and combustion tests were conducted. Analytical test runs were conducted using fish standard samples to confirm the validity of the developed system. The test values were compared with values obtained with another analysis method, and the recovery rate of the combustion water was evaluated. The results confirmed that the analytical values obtained with this combustion system were equivalent to those obtained with another analytical method and were valid for OBT analysis.

THE INFLUENCE OF ORGANIZATIONAL CITIZENSHIP BEHAVIOR, TEAMWORK, OCCUPATIONAL HEALTH AND SAFETY WORK ON EMPLOYEE PERFORMANCE PT. BAHTERA BAHARI SHIPYARD BATAM

This study aims to determine the effect of Organizational Citizenship Behavior, Teamwork, Occupational Health, and Occupational Safety on Employee Performance of PT Bahtera Bahari Shipyard Batam. This study uses a quantitative approach with data collection methods using a questionnaire. The population of this study were all employees of PT Bahtera Bahari Shipyard Batam, totaling 254 employees, with sampling using the Slovin formula so as to obtain respondents totaling 72 employees. The analytical test tool used is SPSS (Statistical Program for Social Science) version 29. The results of this study found that (1) There is a positive and significant effect of Organizational Citizenship Behavior on employee performance, (2) There is a positive and significant effect of Teamwork on employee performance, (3) There is a positive and significant effect of Occupational Health on employee performance, (4) There is no positive and significant effect of Occupational Safety on employee performance, (5) Organizational Citizenship Behavior, Teamwork, Occupational Health, and Occupational Safety simultaneously have a positive and significant effect on Employee Performance of PT Bahtera Bahari Shipyard Batam.

Analytical Design and Test of Licorice Harvester Based on DEM–MBD Coupling

This study addresses the issues of high operating resistance, incomplete separation in ascending transport chains, and significant wear and tear in existing licorice harvesters. A new licorice harvester has been designed that incorporates a lift chain conveyor separation device, enabling excavation, separation, collection, and centralized stacking to be completed in a single operation. The paper describes the harvester’s overall structure and provides detailed analyses and designs of its key components, including the digging shovel, roller screen, conveying and separating screens, and soil-crushing roller. Multi-body dynamics (MBD) and discrete element models (DEM) for licorice and soil were developed, and the entire harvesting process was simulated using the coupled DEM–MBD method to analyze the trajectory and speed of the licorice. Field tests confirmed that the conveyor separation screen operates smoothly, effectively separates licorice rhizomes from soil, and minimizes damage to the licorice. Field test results show a net digging rate of 96.2%, a damage rate of 4.3%, and an average digging depth of 580 mm. The operational indexes meet the standards for harvesting root and stem Chinese herbal medicines. The machine operates stably and exhibits exceptional conveying and separating effects, demonstrating its suitability for mechanized harvesting of root and stem herbs.

The Role of Uterocervical Angle on Preterm Birth Incidence

Background: Preterm birth (PB) is associated with significant morbidities in surviving infants. Accurate prediction of PB is essential for effective prevention and management. Continuous monitoring of cervical parameters has shown utility in several studies. Objectives: This study aimed to investigate the role of the anterior uterocervical angle (UCA) in predicting the incidence of PB. Methods: A prospective, descriptive-analytic study was conducted with 165 pregnant women referred to the prenatal care clinic at Yas Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran, in 2021 - 2022. Participants were selected through convenience sampling. Cervical parameters, including UCA, length, and width, were measured via vaginal ultrasound during each trimester. All women were followed until delivery to determine PB incidence. Data were analyzed using descriptive and analytical statistical tests, including the chi-square or Fisher’s exact test and the independent samples t-test or Mann-Whitney U test. Results: Among the participants, 12 (7.3%) experienced preterm delivery. Cervical length was significantly shorter in women with PB during the second trimester (32.58 ± 4.77 mm vs. 34.68 ± 3.80 mm, P = 0.042) and third trimester (30.00 ± 4.74 mm vs. 32.77 ± 3.88 mm, P = 0.022). The mean UCA in women with preterm delivery was higher than in those with term delivery during both the second (90.58 ± 17.21° vs. 88.66 ± 16.76°) and third (100.25 ± 14.56° vs. 98.89 ± 17.78°) trimesters (P > 0.05). A UCA greater than 105° in the second trimester had a sensitivity of 16.7% and specificity of 81.5% for predicting PB. In the third trimester, a UCA greater than 105° showed a sensitivity of 58.3% and specificity of 60.7% for predicting PB. Conclusions: This study emphasizes the importance of regular cervical parameter measurements throughout pregnancy. A UCA greater than 105° in the third trimester appears to be a potential predictor of PB.

Sustainable barrier coatings for paperboard packaging: Effect of VeoVa-10 on 2-EHA and MMA containing water-based emulsions

Developing environmentally benign barrier coatings may provide a sustainable alternative to the packaging sector and facilitate minimizing the consumption of single-use plastics in packaging. The synthesis of seven different water-based (W/B) emulsions was achieved via seeded emulsion polymerization using 2-Ethylhexylacrylate (2-EHA), methyl methacrylate (MMA), and a varying amount of vinyl ester of Versatic™ acid 10 (VeoVa-10) to impart the hydrophobic properties. Potassium persulfate (K2S2O8) was used as an initiator. Antifoaming agent and biocide were also added to improve the application and shelf-life of these coatings. The coatings were evaluated by conducting various analytical tests, including pH measurement, viscosity assessment, determination of solid content, measurement of drying time, evaluation of gloss, water absorption testing using Cobb's Test, and assessment of oil and grease resistance via the Kit Test. The coatings were also analyzed using advanced characterization techniques, including Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Zetasizer Nano ZS, and contact angle analysis. The results indicated that as the amount of VeoVa-10 increases in barrier coatings, the coated paperboard demonstrated improved moisture and oil/grease resistance compared to the control paperboard (uncoated). Furthermore, the coatings were also applied on paperboard trays and stored at 0 °C and 90 °C to confirm their practical usefulness, a careful examination after an hour showed no leakage/seepage of hot and cold water through the coated trays, unlike the uncoated ones. Barrier coatings offer sustainable and eco-friendly options that could positively impact the packaging industry, helping reduce environmental footprints while enhancing packaging performance.

Pengaruh Pajak Daerah, Retribusi Daerah dan Lain-Lain Pendapatan Asli Daerah yang Sah Terhadap Belanja Daerah di Kabupaten Karawang TAhun 2018-2022

This research aims to analyze and explain the influence of regional taxes on regional expenditure, to determine the influence of regional levies on regional expenditure, to determine the influence of other legitimate regional original income on regional expenditure. To find out and analyze simultaneously regional taxes, regional levies, other influences of legitimate regional original income on regional expenditure in Karawang district. This research method uses quantitative verification, the sample used is the Karawang district realization report. The analytical test used is multiple linear regression analysis, with partial and simultaneous hypothesis testing. The results of this research show that regional taxes partially have a positive and significant effect on regional spending with a contribution of 42.51% which has a strong relationship with regional spending. Regional levies partially have a positive and significant effect on regional spending with a contribution of 17.06% which has a weak level of relationship with regional spending. Other partially valid PAD does not have a significant but positive effect on regional spending because it has a contribution of 10.96% which has a weak level of relationship with regional spending. Regional taxes, regional levies and others -others: Legal PAD simultaneously has a positive and significant effect on regional spending with a contribution of 50.9%, while heredity is influenced by other people

Evaluation of Knowledge, Skill and Satisfaction Level of Laboratory Sciences Students in Pre-laboratory Immunohematology Course Using Virtual Flipped Classroom

Background: Medical education emphasizes the importance of facilitating deep learning, promoting professional behavior, and fostering skillful problem-solving in practical courses. Objectives: To determine student satisfaction, knowledge, and skill levels using the virtual flipped classroom method for the pre-laboratory immunohematology course in laboratory sciences. Methods: This semi-experimental (before-after) study included 42 laboratory science students who completed the practical immunohematology course. The intervention involved three steps of the virtual flipped classroom method. Knowledge was assessed with multiple-choice questions (MCQs), satisfaction was measured using a rating scale, and students' skills were evaluated using a rating scale. Data were analyzed using descriptive and analytical statistical tests in STATA 14. Results: The results showed that the post-test knowledge score had an average of 7.42, significantly higher than the pre-test score of 4.04 (P < 0.05). Additionally, 92.85% of students reported being satisfied with the course. Regarding skill evaluation, 95.23% of students stated, "I think I have now really achieved it or a part of it." Conclusions: The virtual flipped classroom method in the immunohematology pre-laboratory course had a positive impact on students' learning and satisfaction. This teaching approach has the potential to improve teaching effectiveness, create an interactive learning atmosphere, and could be implemented in similar courses.

Unlocking underground hydrogen storage potential: Geochemical characterization of North Dakota's geological formation

Underground hydrogen storage offers a promising solution for sustainable energy, with geologic formations such as salt caverns, aquifers, and depleted hydrocarbon reservoirs identified as suitable options for safely storing hydrogen. Some studies have been carried out to investigate hydrogen-rock-fluid interactions. However, none have simultaneously combined experimental analysis and geochemical modeling of the equilibrium and kinetic reactions using a well-characterized North Dakota carbonate formation as a case study to investigate its geochemical characterization and implications. This research explores the mineralogical and fluid composition of specific depleted hydrocarbon reservoirs in North Dakota while investigating the intricate geochemical interplays between hydrogen gas, fluid, and rock formations. This study focused on the Red River Formation, a primary hydrocarbon-producing entity in North Dakota, to unveil its potential for underground hydrogen storage (UHS). This formation's stratigraphic complexity and extensive hydrocarbon yield underscores its significance. We conducted experiments combining analytical tests and geochemical modeling using core samples from the Red River Formation. X-ray diffraction (XRD), X-ray fluorescence (XRF) spectroscopy, and scanning electron microscopy (SEM) techniques were employed to decipher mineralogical and elemental constituents. This study covers areas such as the Bicentennial, Coyote Creek, Horse Creek, and Medicine Poll Hills Fields and identified common minerals such as calcite, dolomite, anhydrite, and quartz, along with essential elements such as oxygen, magnesium, aluminum, and silicon. Geochemical simulations were also performed to evaluate the equilibrium and kinetic reactions expected during hydrogen gas injection into this formation. Our findings revealed stable mineral phases, the absence of detrimental environmental impacts, promising prospects for hydrogen storage in the studied carbonate reservoirs without geochemical alterations and promising a sustainable pathway toward net-zero carbon emissions.

Determining the frequency of pressure ulcers incidence and associated risk factors in critical care patients: A 3-year retrospective study.

One of the key measures to prevent pressure ulcer is to identify the factors that influence them. This study aimed to assess the occurrence of pressure ulcers and their related risk factors in patients admitted to specialized care units. This research is a retrospective cohort study that was conducted in the critical care units of hospitals affiliated to Ardabil University of Medical Sciences. A total of 1158 patient records who were hospitalized in the intensive care unit (ICU) between 2021 and 2022 were selected from the research population using the available sampling method and based on the inclusion criteria. Data was collected using a researcher-made checklist between April 2021 and December 2022. Data were analysed using analytical tests (chi-squared test, regression test) and descriptive statistics (prevalence, mean, standard deviation, and median) tests. All 1158 patient files were examined without any sample loss. The average age of the patients was 58.59 ± 19.73 years. The study found a significant association between the occurrence of pressure ulcers and age, duration of hospitalization, weight, body temperature, and male gender (p-value <0.001). Additionally, there was a significant association between the occurrence of pressure ulcers and the use of pain relievers, vasopressors, alpha-blockers, calcium blockers, and angiotensin (p-value 0.001). The study also investigated the association between nursing care practices and the development of pressure ulcers. The findings revealed that changing the angle of the bed, using a wavy mattress, repositioning the patient every 2 h, using a CPR bed for mobility, providing protective equipment, and applying physical restraint to the patient were all significantly associated with the likelihood of pressure ulcers (p < 0.001). The study showed that pressure ulcers in ICU patients are influenced by the type of disease and clinical factors in individuals. However, considering the conflicting results of this study with some other studies, more research is needed on this subject. It is suggested that appropriate measures be taken based on the patient's condition to prevent pressure ulcers in those admitted to the ICU.

Numerical Optimization of Hall Effect Thruster with variation in Magnetic Field

In the present study, numerical analyses were conducted to enhance the strength of the magnetic field. While electromagnetic coils and permanent magnets have conventionally been used for this purpose, the study explores the utilization of superconducting magnets, known for their significantly stronger magnetic fields. Through analytical tests on a thruster powered by a 5-kW source at 400 V, and 12.5 A current, computer simulations are conducted using an open-source HallThruster.jl developed using Julia language which gave 1D simulation of plasma properties of Hall effect thruster (HET), along a thrust of 0.687 N was achieved representing a three times greater increase, and specific impulse increasing to 3097 sec which is 1.7 times more compared to conventional results, accompanied by improved plasma parameters. Furthermore, to study the particle behavior the Particle In cell (PIC) approach was utilized, from which particle motion due to the magnetic field was achieved. By enhancing the magnetic field, we can significantly boost thrust, unlocking new possibilities for exploring distant planets and conducting long-duration space missions. Utilizing superconducting materials ensures continuous, efficient operation with increased thrust and fewer operating payloads, ultimately enhancing overall spacecraft functionality. This advancement paves the way for future innovations in space exploration and applications.

Development and clinical utility of an ultra performance liquid chromatography − tandem mass spectrometry assay for monitoring omadacycline and tigecycline in severe bacterial infections

ObjectiveWe aimed to develop a rapid, simple, and precise ultra performance liquid chromatography − tandem mass spectrometry (UPLC-MS/MS) technique for simultaneous measurement of omadacycline (OMA) and tigecycline (TGC) in the bloodstream of individuals suffering from serious bacterial infections. MethodsAll analytes were extracted using a 0.2 % formic acid–water dilution and acetonitrile plasma protein precipitation. The quantification was performed by electrospray ionization-triple quadrupole mass spectrometry with selected reaction monitoring and positive ion mode detection. Tetracycline was used as an internal standard in this experiment, with the mobile phase composed of water (with 0.1 % formic acid) and acetonitrile (using gradient elution) flowing at a rate of 0.35 ml/min, and the column temperature set at 30 °C. Each individual analysis was completed in under 3.5 min. ResultsThe method was validated based on FDA recommendations, including the assessment of extraction recovery (92.65–101.72 %) and matrix effects (86.22–91.12 %). The standard curve ranges for both OMA and TGC are 0.025 µg/mL to 2.5 µg/mL. The plasma samples were found to be consistent after undergoing three rounds of freezing and thawing at room temperature for 24 h, being placed in an automated sample injector for 24 h, and then frozen for 45 days. Clinical cases were used to demonstrate the application of the therapeutic drug monitoring (TDM) assay, showing how an analytical test can quickly provide information on antibiotic levels in patients and impact their treatment. ConclusionMultiplex UPLC-MS/MS assays for the simultaneous measurement of plasma OMA and TGC concentrations are the ideal choice for clinically TDM applications.