Laboratory Equipment Research Articles

Leveraging Artificial Intelligence (AI) for the Maintenance of Science Laboratory Equipment

The dire need for proper maintenance of Science Laboratory Equipment (SLE) to attain efficiency, optimal results and durability cannot be overemphasized. To that end, this study proposes the leveraging of AI for optimization and efficiency in the maintenance of SLE. The study relied on both primary and secondary data. The primary data were sourced from twenty Science Laboratory (SL) professionals, while the secondary data were sourced from repositories, databases and websites on the internet. The mixed method alongside the plausible descriptive and statistical tools was employed. The analysis shows that the maintenance of SLE can be optimized and made efficient by leveraging AI for such purposes. Regrettably, public sector organizations are yet to significantly integrate AI into the maintenance of SLE. The study concludes that AI has the capacity to optimize and enhance efficient maintenance of SLE. It calls on stakeholders in the field of SL to make concerted efforts to significantly integrate AI into the maintenance of SLE. The government should help provide AI technologies for the concerned public sector organizations and sponsor the training of people for technical know-how in using and sustaining these cutting-edge technologies in SL.

Adaptation of a Model Spike Aptamer for Isothermal Amplification-Based Sensing

Isothermal amplification (IA) techniques like rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) have gained significant attention in recent years due to their ability to rapidly amplify DNA or RNA targets at a constant temperature without the need for complex thermal cycling equipment. Such technologies, combined with colorimetric systems rendering visual confirmation of the amplification event, are ideal for the development of point-of-need detection methods suitable for field settings where access to specialized laboratory equipment is limited. The utility of these technologies, thus far limited to DNA and RNA targets, could be broadened to a wide range of targets by using aptamers. Composed of DNA or RNA themselves, aptamers can bind to substances, including proteins, metabolites, and inorganic substances. Their nucleic acid nature can potentially allow them to serve as a bridge, extending the reach of DNA/RNA-centric technologies to the broader molecular world. Indeed, the change in aptamer conformation occurring during ligand interaction can be used to elaborate ligand-responding RCA or LAMP templates. By using an existing aptamer targeting SARS-CoV-2 Spike protein as a model, we explored the possibility of establishing ligand-responsive IA systems. Our study used aptamers with simple sequence modifications as templates in LAMP assays and hyperbranched RCA (HRCA) by exploiting the dynamic nature of the model aptamer to trigger these IA systems. Importantly, our work uniquely demonstrates that this aptamer’s dynamic response to ligand binding can regulate both RCA and LAMP processes. This novel approach of using aptamer conformational changes to trigger LAMP paves the way for new aptamer-based detection assays. Our system detects 50 nM of Spike protein, with LAMP occurring within 30 min in the presence of Spike. The colorimetric readout showed clear results, allowing for the detection of Spike protein presence.

Comparative evaluation of PCR and loop-mediated isothermal amplification (LAMP) assays for detecting Pasteurella multocida in poultry

ABSTRACT Aims To develop a colourimetric loop-mediated isothermal amplification (LAMP) assay for the detection of Pasteurella multocida in clinical poultry samples and compare the performance of this assay with PCR. A secondary aim was to evaluate a simple DNA extraction method that could enable LAMP-based testing in the field without the need for specialised laboratory equipment. Methods Primer sets for both LAMP and PCR were designed to amplify the KMT1 gene of P. multocida. DNA was extracted from 12 P. multocida isolates using a commercial extraction kit, and subjected to analysis using both LAMP and PCR. The analytical specificity of the LAMP assay was evaluated by testing it against a panel of 12 unrelated bacterial species, and the analytical sensitivity (limit of detection) was determined through testing of serial dilutions of the target DNA and compared to that of PCR. Subsequently, cloacal swabs (n = 40) from a commercial turkey flock were subjected to analysis using both LAMP and PCR assays, using a rapid DNA extraction method and a commercial extraction kit. Clinical sensitivity and specificity of the LAMP assay were calculated in comparison to PCR. Results A single DNA fragment of the expected size (∼ 200 base pairs), was amplified by PCR from 12 P. multocida isolates, which were also all positive by the LAMP assay. The identity of all PCR amplicons was confirmed by sequencing. Both PCR and LAMP showed similar analytical sensitivity, with a LOD of 20 pg of target DNA. As neither PCR nor LAMP assays produced positive results with 12 non-related bacterial species, the analytical specificity was assessed as 100%. However, LAMP demonstrated lower clinical specificity (94.74%) compared to PCR (100%) when 40 clinical samples were tested. None of the DNA samples extracted using the simplified DNA extraction method were amplified by either LAMP or PCR. Conclusion The LAMP assay developed in this study exhibits comparable performance to PCR in detecting P. multocida. Clinical relevance The use of a rapid and portable DNA extraction method, in conjunction with LAMP assays, could create opportunities for point-of-care testing for fowl cholera in field settings.

Assessing on-site plastics fragmentation: Linking macroplastics litter to microplastics pollution in vegetable fields

This study proposes a novel approach to determine whether farmers act as a pollution source of microplastics through macroplastic mismanagement or if they are temporary hosts of in-transit microplastics. Using a case-study approach, it was hypothesized that 90 % of soil microplastics would trace back to macroplastic waste mismanaged by farmers. To determine the amount of soil microplastics, linear transects were established and microplastic litter was counted and classified. Additionally, composite soil samples were used to count and colour-classify microplastics. The Kendall correlation was used to differentiate between the colour ranks of macro- and microplastics to discriminate between plastic on-site fragmentation or exogenous plastic pollution. For this, 37 vegetable farms in central Chile were assessed after the growing season. Farms showed lower microplastic counts than previously reported for similar productive conditions (3.68 ± 3.28 u/kg). A median colour correlation of 0.43 (IQR = 0.18–0.55) was observed between macro- and microplastics. Only in 25 % of the studied fields did on-site plastic fragmentation predominate over exogenous plastic pollution. The applied approach is simple to implement and does not require specialized laboratory equipment. We hope that the proposed methodology will serve in environmental monitoring to evaluate adherence to good agricultural practices and to guide pollution-prevention measures.

Assessing effectiveness of cleaning and disinfection of equipment and environmental surfaces in cystic fibrosis clinics using an ATP assay.

Infection control guidelines for cystic fibrosis (CF) stress cleaning of environmental surfaces and patientcare equipment in CF clinics. This multicenter study measured cleanliness of frequently touched surfaces in CF clinics using an ATP bioluminescence assay to assess the effectiveness of cleaning/disinfection and the impact of feedback. Eight surfaces were tested across 19 clinics (10 pediatric, 9 adult) over 5 rounds of testing. Rounds 1 and 2 served as uncleaned baseline, and Round 3 occurring after routine cleaning. Rounds 4 and 5 were performed after feedback provided to staff and measured after cleaning. Pass rates defined as <250 relative light units were the primary outcome. Of the 750 tests performed, 72% of surfaces passed at baseline, and 79%, 83%, and 85% of surfaces passed in Rounds 3, 4, and 5, respectively. The overall pass-rate was significantly higher in adult compared to pediatric clinics (86% vs 71%; P < 0.001). In pediatric clinics, blood pressure equipment and computer keyboards in the pulmonary function lab consistently passed, but the exam room patient/visitor chairs consistently failed in all rounds. In adult clinics blood pressure equipment, keyboards in exam rooms and exam tables passed in all rounds and no surface consistently failed. We demonstrate the feasibility of an ATP bioluminescence assay to measure cleanliness of patient care equipment and surfaces in CF clinics. Pass rates improved after cleaning and feedback for certain surfaces. We found that surfaces are more challenging to keep clean in clinics taking care of younger patients.

EXPERIMENTAL RESEARCH OF THE MAGNETIZATION AND DEMAGNETIZATION PROCESSES OF THE VECTOR-CONTROLLED INDUCTION MOTOR

Experimental research of the processes of magnetization and demagnetization for the motionless vector-controlled induction motor was performed, according to a linear law with a variation in the duration of these processes. The methodology of research during which the orthogonal components of the stator and rotor currents were recorded in the rotor flux reference frame, the rotor flux module and the energy of the total losses in the stator and rotor copper is described. The main characteristics and parameters of laboratory equipment and facilities are given. From the point of view of minimizing copper losses, the existence of the optimal duration of the investigated transient processes has been experimentally proven. The results of experimental studies with high accuracy coincide with calculations based on previously obtained analytical dependencies, which confirms the admissibility of the assumptions made during theoretical studies. References 10, figures 7, tables 2.

Electroanalytical overview: the sensing of the mycophenolate mofetil and mycophenolic acid.

In this review, we explore the electroanalytical determination of mycophenolate mofetil and mycophenolic acid. Mycophenolate mofetil is a prodrug of mycophenolic acid, which is an immunosuppressive agent used to lower the body's natural immunity in patients who receive organ transplants as well as to treat autoimmune conditions. Laboratory based analytical instrumentation provide a routine methodology to measure mycophenolate mofetil and its metabolites, but there is scope to develop in-the-field analytical measurements that are comparable to those from laboratory equipment. Electroanalysis provides an opportunity to provide highly selective and sensitive outputs but are cost-efficient and can support on-site analysis. In this review, we provide an electroanalytical overview of the current research directed toward the measurement of mycophenolate mofetil and mycophenolic acid, offering insights to future research.

National recommendations of the Croatian Chamber of Medical Biochemists and Working group for Laboratory hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine: Management of samples with suspected EDTA-induced pseudothrombocytopenia.

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions (i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management (i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions (i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results.

Development of a calibration management and critical analysis software using NFC technology

The ISO 17025 standard from 2017 aims to ensure the quality of services and results obtained through laboratory equipments. The standard guarantees that equipment testing, calibration, and maintenance are carried out according to internationally accepted quality standards, which ensures greater efficiency, lower costs, and conveys more trust to clients. In this work, it is presented the development of an application to manage the calibration of equipment in a company, along with a critical analysis of certificates. This application was developed for Android and iOS using the Flutterflow tool, and all the information regarding the equipment is securely and efficiently stored in a Firebase Firestore database. The application also supports the use of NFC tags integrated with the equipment to facilitate access to information in hard-to-reach environments. The solution is already in operation in two companies and has shown great potential for use in other companies for equipment calibration management.

Comparison of lab-produced asphalt emulsions by manufacturing equipment type

Asphalt emulsions can be produced with colloid mills and high-speed shear mixers, but effects of equipment type on emulsion properties are largely unknown. The study objective was to assess the impact of different manufacturing equipments on emulsion properties. Particle size, viscosity, residue, sieve and storage stability properties were observed after production on three emulsion manufacturing devices. For each device, three emulsions were manufactured by three operator pairs. Median particle size was as small as 2.0 microns on recirculating and in-line equipment, but only 5.3 on high-speed shear mixer. Recirculating equipment also produced emulsion with better storage stability than high-speed shear mixer and in-line equipment. In-line manufactured emulsions had the highest viscosity while the shear-mixed emulsion viscosity was below specification. Sieve was significantly affected by the operator. These results demonstrate that emulsions produced by different laboratory equipment are not identical, and caution must be exercised when comparing and manufacturing lab-produced emulsions.

A Design Review for Biomedical Wireless Power Transfer Systems with a Three-Coil Inductive Link through a Case Study for NICU Applications

This paper outlines a design approach for biomedical wireless power transfer systems with a focus on three-coil inductive links for neonatal intensive care unit applications. The relevant literature has been explored to support the design approach, equations, simulation results, and the process of experimental analysis. The paper begins with a brief overview of various power amplifier classes, followed by an in-depth examination of the most common power amplifiers used in biomedical wireless power transfer systems. Among the traditional linear and switching amplifier classes, class-D and class-E switching amplifiers are highlighted for their enhanced efficiency and straightforward implementation in biomedical contexts. The impact of load variation on these systems is also discussed. This paper then explores the basic concepts and essential equations governing inductive links, comparing two-coil and multi-coil configurations. In the following, the paper discusses foundational coil parameters and provides theoretical and experimental analysis of both two-coil and multi-coil inductive links through step-by-step measurement techniques using lab equipment and addressing the relevant challenges. Finally, a case study for neonatal intensive care unit applications is presented, showcasing a wireless power transfer system operating at 13.56 MHz for powering a wearable device on a patient lying on a mattress. An inductive link with a transmitter coil embedded in a mattress is designed to supply power to a load at distances ranging from 4 cm to 12 cm, simulating the mattress-to-chest distance of an infant. the experimental results of a three-coil inductive link equipped with a Class-E power amplifier are reported, demonstrating power transfer efficiency ranging from 75% to 25% and power delivery to a 500 Ω-load varying from 340 mW to 25 mW over various distances.

Fluorescence Polarization Assay for Infection Diagnostics: A Review

Rapid and specific diagnosis is necessary for both the treatment and prevention of infectious diseases. Bacteria and viruses that enter the bloodstream can trigger a strong immune response in infected animals and humans. The fluorescence polarization assay (FPA) is a rapid and accurate method for detecting specific antibodies in the blood that are produced in response to infection. One of the first examples of FPA is the non-competitive test for detecting brucellosis in animals, which was followed by the development of other protocols for detecting various infections. Fluorescently labeled polysaccharides (in the case of brucellosis and salmonellosis) or specific peptides (in the case of tuberculosis and salmonellosis, etc.) can be used as biorecognition elements for detecting infections. The availability of new laboratory equipment and mobile devices for fluorescence polarization measurements outside the laboratory has stimulated the development of new fluorescence polarization assays (FPAs) and the emergence of commercial kits on the market for the detection of brucellosis, tuberculosis, and equine infectious anemia viruses. It has been shown that, in addition to antibodies, the FPA method can detect both viruses and nucleic acids. The development of more specific and sensitive biomarkers is essential for the diagnosis of infections and therapy monitoring. This review summarizes studies published between 2003 and 2023 that focus on the detection of infections using FPA. Furthermore, it demonstrates the potential for using new biorecognition elements (e.g., aptamers, proteins, peptides) and the combined use of FPA with new technologies, such as PCR and CRISPR/Cas12a systems, for detecting various infectious agents.

HRTF individualization using ear images from 3D meshes

The head-related transfer function (HRTF) describes how a human receives sound from different directions in space. It is unique to each listener. The best way to obtain an individualized HRTF is through direct measurement, but it requires sophisticated laboratory equipment and long measurement times. This work proposes an approach for HRTF individualization employing ear images from 3D meshes using a deep neural network and spherical harmonics transform (SHT). The method relies on the HUTUBS dataset, including 3D meshes and HRTFs. The model uses ear images to predict a low-dimensional representation of the HRTF. Initially, ten images of the right ear of each 3D mesh are taken in different positions. The model consists of two main parts. The first is a convolutional neural network (CNN), which is used to extract features from the ear images. The second part learns from the feature map obtained and predict the spherical harmonic coefficients. Finally, the individualized HRTF is obtained through inverse SHT. The performance of the method is evaluated by computing the log-spectral distortion (LSD) between the measured HRTF and the predicted one. The results show favorable LSD values compared to other models addressing the same problem.

Development of CadR-based cadmium whole cell biosensor for visual detection of environmental Cd2+

BackgroundAs a threat to human health and public health, cadmium (Cd) pollution has received widespread social concern. Our previously constructed CadR-based bacterial whole cell biosensor (WCB) epCadR5 showed high sensitivity and specificity in cadmium detection. However, the application of the sensor is still hindered by the need for laboratory equipment to read the fluorescence signal output. In this study, we aimed to optimizing the sensor to make it available for visual detection of environmental cadmium and simplify the detection process to advance practical application of the sensor. ResultsBy replacing the constitutive promoter with J110, the fluorescence signal output of the sensor was significantly increased and the fluorescence leakage was decreased. In addition, the fluorescence signal output of green fluorescence protein (GFP) was enhanced by the addition of a 5′ untranslated region (5′-UTR) mlcR10. The fluorescence signal output of the WCB is sufficiently robust to be visible and distinguishable to the naked eye, which is of paramount importance for visual detection. The sensor readout can be conveniently recorded by mobile phone camera and quantified. For ease of on-site application, the WCB's visual detection procedures and conditions were further optimized and simplified. The WCB demonstrated good linearity and detection limit (1.81 μg/L) for visual detection of Cd2+ without the assistance of bulky laboratory equipment. For the detection of real environmental samples, the WCB visual detection results were close to those of WCB-flow cytometry (FACS) and graphite furnace atomic absorption spectroscopy (GFAAS). SignificanceIn this work, we developed an easy-to-use, on-site and visual detection biosensor for monitoring environmental Cd2+. It will advance the utilization of cadmium WCBs in practical settings. The optimization and simplification strategy in the study also provide new insights into the visualization of other bacterial biosensors, and will advance the practical application of WCBs.

A-262 Novel Hepatitis C Virus External Quality Control that is Stable at Ambient Temperature and Suitable For Use in Low-Resource Settings

Abstract Background Notwithstanding the WHO’s initiative to eliminate viral hepatitis by 2030, there are currently 58 million individuals infected with Hepatitis C Virus (HCV). 73% of infected individuals live in low- and middle-income countries (LMIC) where conventional diagnostics are inaccessible due to high costs and lack of trained personnel. The emergence of low-complexity Point of Care tests is critical for improving accessibility and reducing the spread of infection. Additionally, there is a need for external quality controls (EQC) that monitor the accuracy of test results. Given that LMIC have limited access to laboratory equipment, EQC must have simplified handling procedures and storage conditions. Unfortunately, these materials are not available at scale. Microbix strived to develop HCV EQC swab formulations that are stable at ambient temperature. Since this format deviates from standard HCV diagnostic workflows, we sought to establish a simple yet reproducible workflow that can be followed by laboratories worldwide. Methods Microbix developed HCV swab-based EQC that are stable when stored at 2-30°C. The contrived specimens are formulated with protected synthetic HCV whole-genome nucleic acid and human cells. The formulation was quantified via ddPCR and benchmarked against the WHO HCV standard using Xpert® HCV Viral Load Fingerstick Assay. Sample performance was evaluated with various elution buffers (PrimeStore® MTM, eNAT®, TE buffer, Microbix’s proprietary buffer) and handling procedures that require minimal use of laboratory equipment. Each EQC workflow was assessed based on its ability to consistently demonstrate a viral load of 100-200 IU/mL when tested on Cepheid’s platform. Results The EQC tested positive for HCV when eluted in each buffer and processed using a hand-mixing procedure. Only the workflows that used PrimeStore® MTM or eNAT® consistently reported a viral load between 100-200 IU/mL. Conclusions Microbix developed an HCV swab-based EQC that is stable at ambient temperature; however, we observed that consistent elution conditions are imperative for achieving reproducible results. Our findings demonstrate that a universal workflow should be followed to standardize results across testing sites as deviations in elution buffers, volumes, and handling procedures can influence test outcomes.

A-206 Exploring the Surge in Clinical Laboratory Inflation: A Comprehensive Review

Abstract Background The healthcare industry has been experiencing significant inflationary trends, particularly in clinical laboratory services. This surge in inflation is attributed to various factors, including the increased demand for laboratory services, changes in the practice of clinical laboratory science due to technological advances, and vacancy rates that exceed the number of Medical Laboratory Science (MLS) graduates. Additionally, supply chain shortages, increased operational costs, and staffing budget increases, further exacerbating the inflationary pressures on clinical laboratory services. Methods The review of the factors behind the surge in clinical laboratory inflation involved a comprehensive review of industry data and insights from supply chain leaders, and recent surveys conducted by the author sent to 50 laboratory leaders with a response rate of 50%, Data from the Bureau of Labor Statistics (BLS) and industry interviews were integrated to provide an understanding of the inflationary trends affecting the healthcare industry, with a specific focus on clinical laboratory services. Results The review revealed that domestically produced healthcare inputs, labor, diagnostics, and lab equipment have seen dramatic price increases. For instance, prices manufacturers charge for diagnostic reagents for testing have increased by 9.2%, while lab equipment prices have risen by 7.1%. Some product lines have experienced increases of 15-20%. Moreover, the post pandemic has led to attrition rates climbing from 10%-37% to the current rate of 35%-61%, resulting in 30%-50% staffing budget increases. 36% of lab leaders feel Group Purchasing Organizations (GPO’s) are incentivized to allow increases, it’s estimated that as much as 80% of GPO revenue is generated by fees paid by vendors. 28% feel the vendors are passing along but not sharing in the inflationary pressures as reimbursements decline. 20% feel it’s an excuse for vendors to pad margins. 16% feel that it’s due to lack resources or lab specific procurement expertise in supply chain departments. Conclusions These factors have contributed to the significant surge in clinical laboratory inflation. The surge in is a complex phenomenon influenced by multiple interconnected factors. Addressing this inflationary trend will require a collaborative approach that considers the impact of supply chain shortages, increased operational costs, and staffing. Proactive measures to mitigate the adverse effects of inflation on clinical laboratory services, such as ensuring reliable data in negotiations, addressing the workforce shortage and strong negotiations with vendors will be essential to sustain the cost, quality, and accessibility of these critical healthcare services.

Transformative Advances in Veterinary Laboratory Practices: Evaluating the Impact of Preliminary Training in Khyber Pakhtunkhwa and Balochistan Provinces of Pakistan

Veterinary laboratories face distinct challenges in Pakistan, including inadequate infrastructure, resources, and training opportunities, especially in the Khyber Pakhtunkhwa and Balochistan regions. This study aimed to evaluate the impact of training sessions for veterinary laboratory staff to improve methods and protocols related to sample collection, storage, and transport, while ensuring strict compliance with biosafety and biosecurity guidelines. The study employed a mixed methods approach, incorporating qualitative and quantitative research techniques. Hands-on training, essential laboratory equipment, and a comprehensive training kit, including personal protective equipment (PPE), were provided to 13 laboratories within the Livestock and Dairy Development Departments of Khyber Pakhtunkhwa and Balochistan. A random sample of 152 individuals from a cohort of 314 trained personnel was selected to assess procedural changes post-training, supplemented by Training Needs Assessments (TNAs) and follow-up visits. Data collection involved a combination of open- and closed-ended questionnaires, individual interviews, and focus group discussions by trained enumerators to maintain a standardized approach. Significant improvements were observed in laboratory practices and procedures, staff competency in sample collection, necropsy techniques, labeling, storage, a chain of custody, packaging, and transport, as well as biosafety and biosecurity practices, such as effective use of PPEs, good laboratory practices, standard operating procedures, handling of sharps, and waste management. However, areas needing refinement, particularly waste management protocols, were identified. The integrated approach combining TNAs, training initiatives, and resource distribution, including laboratory equipment and PPEs, was pivotal in achieving these outcomes. This comprehensive strategy provides a basis for improving biosafety and biosecurity measures within laboratories, thereby contributing to the global effort to mitigate unauthorized access to high-risk pathogens.

High-throughput LC-PDA method for determination of Δ9-THC and related cannabinoids in Cannabis sativa

Before the passage of the Agriculture Improvement Act of 2018, more commonly referred to as the 2018 Farm Bill, forensic laboratories were only required to perform qualitative measurements to confirm the identity of seized plant samples as Cannabis sativa (hemp or marijuana). The new law defines hemp at a federal level as Cannabis sativa containing 0.3 % or less Δ9-THC. Because forensic laboratories were not adequately equipped with the proper methods or training to meet these requirements, significant backlogs in casework resulted. The National Institute of Standards and Technology (NIST) responded by providing analytical tools to the forensic community. An accurate and precise method was previously developed to determine Δ9-THC, Δ9-THCA, and total Δ9-THC in botanical samples based on liquid chromatography with photodiode array detection (LC-PDA). Cannabis plant samples were ground and extracted with methanol using routine laboratory equipment. The original sample preparation procedure was time-consuming, taking over 70 min. The method described here has been optimized with the time required for sample preparation and LC-PDA analysis has been reduced to less than 30 min.

Assessing Implementation of Strengthening Mathematics and Science in Secondary Education (SMASSE): In the Case of Selected Secondary School of Kellem Wollega Zone, Oromia Regional State, Ethiopia

This study aimed to identify the methods teachers use to integrate science and mathematics. These factors affect the implementation of integrated science and mathematics education and students' attitudes toward this integration in secondary schools in the Kellem Wollega zone of Ethiopia. Both open-ended and closed-ended questionnaires, along with structured interviews, were designed for the selected sample population. This targeted population was chosen from five different sites within the zone, comprising a total of 506 samples, of which 392 were students and 114 were teachers and school principals. The study found that teachers integrate science and mathematics using the PDSI approach, the ASEI approach, a student-centered approach, and generally the SMASSE approach. They employ various strategies, including assigning projects, conducting practical work with students, providing assignments and worksheets, and fostering team spirit among students. Several factors hindering the implementation of SMASSE in the study area were identified, including the teacher-student ratio, the disproportion between class size and the number of students, students' attitudes toward science and mathematics, a lack of laboratory facilities and equipment, an absence of a planned schedule, insufficient access to computers, inadequate assessment practices, a lack of sufficient time to complete the curriculum, and an inadequate quality assurance system. On the other hand, students exhibited a negative attitude toward the integration of science and mathematics education, which was influenced by factors such as their perceptions of mathematics, student-teacher interactions, feedback from teachers, teaching methods, course content, teachers' competencies, school management, and limited student participation in the classroom.

Spectrophotometric Determination of Norepinephrine in Industrial Equipment Cleaning Rinse Water by Its Own Absorbance and The Tollens’ Reagent

A literature review of the available spectrophotometric methods of determination of catecholamines is presented. Based on this review, two simple spectrophotometric methods for the determination of norepinephrine bitartrate in pharmaceutical formulations and industrial equipment cleaning rinse waters were chosen and validated. The first method for the determination of norepinephrine at ppm levels utilizes the absorbance band of the solution of norepinephrine bitartrate at 279 nm. The second method for the determination of norepinephrine at ppb levels is based on the reaction of norepinephrine with the Tollens’ reagent in the presence of the cationic surfactant cetylpyridinium chloride and the colorimetric determination of the formed colloidal silver nanoparticles. The calibration graphs are linear in the range from 1 to 150 mg/l of norepinephrine for the first method and 25 µg/l to 10 mg/l for the second method. The molar attenuation coefficients are 388 and 7560 m2/mol, respectively, the limits of detection are 1.1 mg/l and 3.1 µg/l, and the limits of quantification are 3.3 mg/l and 9.4 µg/l, respectively. Both methods are selective concerning the common excipients, show good accuracy (the relative uncertainties do not exceed 4 and 7%, respectively) and precision (the relative standard deviations do not exceed 4 and 7%, respectively), and do not require lengthy sample preparation and sophisticated laboratory equipment.