Simple Laboratory Research Articles

Heterogeneous corrosion of carbon steel used for casing in deep geological radioactive waste repository in contact with claystone

The corrosion of C-steel in contact with the Cox claystone was studied under aerated conditions at 50°C, for 7 years, in a simplified laboratory experiment. A multi-scale and multi-technique approach, including SEM-EDX, Raman spectroscopy and STXM, was used to determine the nature and structure of the corrosion products and to better understand the mechanisms involved in the observed degradation. The effects of temperature, oxygen supply and the local influence of the composition and density of the claystone were examined here.

A simplified laboratory approach for isolating M. oryzae spores from rice samples infected with multiple pathogens

A method for separating M. oryzae from rice samples infected with multiple pathogens using basic laboratory equipment is described. We conducted a series of experiments to obtain a single spore of M. oryzae. This method can also be used to isolate spores from other fungal species.

Uncomplicated appendicitis at Herat Regional Hospital: limited resource is not always the end of the world.

Acute appendicitis is the most common aetiology of acute abdomen in children. Our aim is to describe the accuracy of diagnosis, and complications in a limited resources setting in children between 5 and 14 years old at the only tertiary referral hospital in the West region of Afghanistan. A retrospective study for a period of 1 year (21 March 2015-20 March 2016). Data was collected from patients' files. Data were analysed by epi info 7. We identified 774 children who had appendectomies at Herat Regional Hospital during the study period with complete records available for analysis. The median age was 11 years [5-14]. The rate of positive appendectomy was 87%. 72% of appendectomies were done within 24 h of the onset of symptoms. Of 675 positive appendectomies, the most common clinical features were migratory abdominal pain (90%), nausea/vomiting (80%), RLQ tenderness (90%), and rebound tenderness (81%). Among the 99 negative appendectomies, the most common signs and symptoms were anorexia 68%, nausea/vomiting 59%, RLQ tenderness 79%, and rebound tenderness 43%. 98% of positive and 71% of negative appendectomies had elevated WBC count. Post appendectomy complications occurred in 9% of our patients mostly commonly intra-abdominal abscesses (5%). Although the diagnosis of acute appendicitis is challenging in children and may involve sophisticated imaging techniques, in many settings these are unavailable. Classical manifestations such as migratory abdominal pain, abdominal tenderness, nausea, and simple lab tests play a crucial role in the diagnosis of acute appendicitis in low resource environments.

Investigating resistive and gas sensing properties of TiO2, CuO and TiO2-CuO thick films

New inventions in modern research work related to material science always based on the preparation of a well adhered film (thin or thick) of suitable base material on a suitable substrate and investigating their functional characteristics. In our work we used TiO2 and CuO as base materials. In our work, we prepared thick films of TiO2, CuO and TiO2-CuO films of variable percentage. All the films were prepared on a suitably small electrode pattern Printed Circuit Board. Then the I-V characteristic of all prepared thick film was investigated by simple lab prepared two probe method. Variation in resistive properties of each film was investigated. Also, gas sensing performance of each film was investigated.

Effect of flexible membrane in triaxial test on the mechanical behaviour of rockfill material using Discrete Element Method

The investigation of rockfill materials poses challenges due to their large particle size, associated high cost, and long laboratory testing duration. As a result, empirical correlations based on historical experimental studies are commonly used to design and analyse rockfill structures. However, the extensive use of rockfill in a wide range of applications and limited understanding of its mechanical behaviour emphasize the need for further research. These make it necessary to develop a robust technique capable of capturing key parameters such as particle shape and breakage, allowing for the simulation and study of large-scale assemblies with realistic boundary conditions. Given that the behaviour of rockfill is highly scale-dependent, primarily due to particle breakage, the simplified laboratory tests on the scaled-down assemblies can be misleading. Particle breakage is a fundamental phenomenon in the mechanical behaviour of rockfill and significantly affects shear strength, deformability, and porosity under different stress levels. The particle breakage is influenced by factors such as the rockfill’s maximum particle size, mineralogy, particle shape, gradation, and confining stresses. This study adopts a computationally efficient breakage method called the Modified Particle Replacement Method (MPRM) based on the Discrete Element Method. A Tile-Based Flexible Membrane (TBFM) for triaxial test modelling has been developed by employing segmental rectangular walls to create a deformable membrane. The effects of critical parameters, including particle shape, confining stress, membrane resolution, degree of flexibility, and the characteristic strength of the particles, are examined. The findings of the combined MPRM-TBFM approach demonstrate the significant influence of membrane flexibility on volumetric-related behaviour.Graphical

Exploring predictive kinetic modelling of thermal degradation from laboratory to production scale – A case study on three vitamins in milk

Kinetic thermal degradation models are vital components for optimization of food and bioproducts processing. Typically, models are fitted to laboratory-scale experiments where vials are heated and held. However, these conditions are highly dissimilar from the thermal processes experienced in industrial production. Whereas fitting kinetic data to industrial-scale production is often impossible due to cost and flexibility issues, this discrepancy between what is typically measured and what the models are intended for could be of concern. This study presents a case study where traditional laboratory experiments are fitted to vitamin degradation kinetic models in milk (vitamins B1, B2, and E). The best-fitted kinetic models are then validated using five, carefully controlled industrial-scale dairy processes. Results show that predictions are surprisingly close to the validation data (mean relative percentual deviation is −1.1 %–+3 % depending on vitamin), given the substantial difference between the laboratory and production scale setup. This offers empirical support for the conventional method of fitting kinetic parameters through simplified laboratory experiments to predict vitamin degradation during industrial scale processing of foods and bioproducts.

A Cost-Effective and Simplified Integration of Simulations and Hands-on Experiments in the Teaching of Electronic Instrumentation and Measurement Laboratory Course

To develop students into effective engineers upon graduation, it is important to bridge the gap between theory and practice. This is achieved through hands-on laboratory experiments, which form an important part of engineering education especially electronic circuits-related courses within the undergraduate level of education. Hence, it is important to develop well-outlined laboratory experiments that reflect the theoretical part of a course. Equally important is comparing simulation and measurement data, to better appreciate the theory. This work presents integrated simulation and hands-on experiments in teaching electronic instrumentation and measurement laboratory course, using low-cost off-the-shelf components. A no-cost circuit simulator software (LTspice) and low-cost breadboard with readily available off-the-shelf circuit components can be used both at home (self-paced) and in the laboratory to motivate students and align results for an improved learning approach. The advantage of this integrated laboratory is that no specialized or expensive teaching kit is required, which improves accessibility and course delivery. In addition, based on the feedback received, students are satisfied with this simplified and low-cost integrated laboratory.

An expanded plasma jet assisted technique for very high-rate synthesis of 2D α-MoO3 nanomaterials, with surface oxygen vacancies and robust induced ferromagnetism

This article reports a novel, clean and energy-efficient thermal-plasma assisted synthesis technique, for very high rate production of defective, ferromagnetic, 2D stoichiometric molybdenum-oxide, maximum up to 750 g/h, but without compromising with the sizes of the nanomaterials or their state of aggregation. A collimated, laminar beam of plasma with large cross-section and uniform profile is produced as the jet expands supersonically into a vacuum chamber that engulfs a large molybdenum target plate and heat it up in a controlled manner. The surface of the target is rapidly oxidized into a sublimating vapour, from which nanometric metal-oxides are nucleated through gas phase condensation process. Surface oxygen-defects are introduced into the product, but even without employing an additional step of defect-engineering, which endowed them with robust room-temperature ferromagnetic properties (maximum saturation magnetization = 1.84 emu/g) and easy dispersibility in aqueous solutions. It is further demonstrated that the as-synthesized, phase-pure α-MoO3 sample with hierarchical morphology can adsorb cationic methylene blue (MB) dyes from an aqueous solution at 94.1 % in 30 min, and the corresponding maximum adsorption capacity is 1045.9 mg/g. The ferromagnetic nanoadsorbents may be separated from wastewater with a simple lab scale magnetic field, to reduce secondary pollution and for reuse of the adsorbents.

Biological control of predatory fungi inhabiting activated sludge in wastewater treatment

The unfavorable phenomenon of activated sludge bulking that occurs in sewage treatment plants (WWTPs) is caused by the over-proliferation of filamentous bacteria that should be limited by the Lecane rotifers that feed on them; however, predatory, rotiferovorous fungi that often inhabit WWTPs pose a real threat to these organisms. To solve this problem, we investigated the interaction of the fungus Clonostachys rosea, which is a known Biological Control Agent (BCA) and the predacious Zoophagus sp. in simplified laboratory culture conditions. The presence of C. rosea in the cultures reduced the number of active traps, thus translating into a much smaller number of rotifers being caught. The mycelium of C. rosea was labeled with a red fluorescent protein (RFP). The life cycle of C. rosea that were attacking Zoophagus sp. (hunting for rotifers) is described. C. rosea spores germinate into single-celled forms and penetrate the interior of the Zoophagus mycelium where they feed on the cytoplasm. Then is the mycelium produced abundantly and forms conidiophores. This type of life strategy has not been known before. The obtained results demonstrated the potential of C. rosea as a BCA that can be used to protect rotifers in the event of an infection of activated sludge by the predatory fungi that threaten the rotifer population.

Design of a test rig for grease endurance tests

BackgroundThe performance and endurance of lubricating greases is often assessed through model tests (like four-ball tests or SRV tests). This approach has some limitations, especially when greases with special fillers are investigated, because simplified laboratory test conditions can never replicate real operating conditions. ObjectiveFor a more reliable assessment on the performance of a lubricating grease, lubricants must be tested in close-to-actual operational conditions, e.g. through component tests. This paper presents both the design and implementation of a dedicated test rig to test lubricating greases through middle-sized thrust ball bearings. MethodsThe test rig design is optimized to monitor the effectiveness of lubrication and determine the useful life of grease by recording representative parameters, namely bearing temperature at different location in the bearing, vibration level, and electric contact resistance (ECR) through the bearing. ResultsThe results of a couple of assessment tests are presented and confirm that the test rig is working as expected. ConclusionsThe chart of the parameters being monitored shows that the instant performance of grease lubrication can be tracked during the endurance tests, and grease failure identified. The special mechanical layout of the rig also allows the user to obtain additional information that is usually not available in other commercial greased bearing testers. This work is meant to be the first step of the development a new approach to evaluate the grease lubrication performance and a few experimental results are included as they are intended as a functional validation of the prototyped test rig.

Small-scale laboratory tests for quantifying aggregate interlocking in short-panelled concrete pavements

In the present study, a simple and reliabe small-scale laboratory test to assess the performance of aggregate interlocked joints in short-panelled concrete pavements in terms of LTE is proposed. In the proposed test method, conventional standard flexural strength test beam specimens (100×100× 500mm) are used for understanding the performance of aggregate interlocking of PQC mix specimens prepared using coarse aggregates of different NMAS and with addition of both micro and macro fibers. The test setup is also modelled in ANSYS FE software. The experimentally obtained LTE is compared with the LTE obtained from the FE model. The field FWD test is conducted for validation. The relative movement is determined from FWD test, and corresponding LTE is determined using the LTE and RM relationship obtained from experimental results using the proposed test apparatus. There exists good linear fit between the LTE determined using proposed test and field FWD test results.

Using Amylase Beads to Investigate Factors Affecting Enzyme Activity

Existing laboratory protocols for investigating the effects of factors affecting enzyme activity often require extensive hands-on manipulations and time. This can result in students either not getting the desired results or being distracted from thinking about the scientific ideas underlying the experimental designs and procedures of these protocols. In this paper, we present a lesson plan that includes a simple microscale laboratory protocol that allows students to study the action of amylase on starch and to investigate the effects of various factors (i.e., temperature, pH, substrate concentration, enzyme concentration, and competitive reversible inhibitors) on enzyme activity using immobilized amylase beads. We also show how to engage students in thinking about procedural knowledge, such as repeating measurements, measurement range, and interval. These concepts are critical to designing valid and reliable scientific investigations.

Quality control of Bradyrhizobium inoculant strains: detection of nosZ and correlation of symbiotic efficiency with soybean leaf chlorophyll levels

Greenhouse gas emissions, such as N2O from excessive N-fertilizer use, are of concern. Symbiotic N2-fixation by pulses such as soybean might mitigate this issue, for which inoculants carrying locally adapted Bradyrhizobium strains are recommended. In the frame of this goal, enhancing the quality control of these inoculants is required on two key aspects: determining the presence of nosZ, for the strains being able to reduce N2O, and assessing N2-fixation potential. Previously it was demonstrated that, in soybean leaves, N-contents are well correlated with chlorophyll contents. However, no such correlations were made with either N obtained from N2-fixation or with nodules mass, which is an indicator of nodular activity. Here we aimed to leverage the correlation between N and chlorophyll levels to develop a simple and non-destructive laboratory method to be applied in quality control of inoculants, able to assess the N2-fixing capacity of rhizobial strains. To establish such correlations, we cultivated soybeans in vermiculite with N-free nutrient solution, and inoculated them with various Bradyrhizobium field isolates that displayed a range of symbiotic N2-fixing capacities. Subsequently, we measured chlorophyll with a portable chlorophyllometer, and correlated these measures with symbiotic parameters. Moreover, we tested for the presence of nosZ by PCR. We observed significant correlations between chlorophyll and shoot nitrogen obtained from N2-fixation and, in addition, we corroborated that chlorophyll contents were significantly correlated also with nodules mass. Two B. diazoefficiens strains stood out and possessed nosZ. In contrast, B. elkanii and B. japonicum isolates displayed lower chlorophyll and symbiotic performance, and lacked nosZ. Our findings highlight the potential of measuring chlorophyll contents and testing for the presence of nosZ as two straightforward techniques that may enhance laboratory tests for quality control, enabling selection of superior and safe locally isolated strains for soybean inoculants without increased production costs.

Pesticide volatilization in biobed systems’ potential substrates. A viable simple laboratory experiment to determine pesticide losses to the environment.

Pesticide volatilization in biobed systems’ potential substrates. A viable simple laboratory experiment to determine pesticide losses to the environment.

New Advances in Rapid Pretreatment for Small Dense LDL Cholesterol Measurement Using Shear Horizontal Surface Acoustic Wave (SH-SAW) Technology.

Atherosclerosis is an inflammatory disease of the arteries associated with alterations in lipid and other metabolism and is a major cause of cardiovascular disease (CVD). LDL consists of several subclasses with different sizes, densities, and physicochemical compositions. Small dense LDL (sd-LDL) is a subclass of LDL. There is growing evidence that sd-LDL-C is associated with CVD risk, metabolic dysregulation, and several pathophysiological processes. In this study, we present a straightforward membrane device filtration method that can be performed with simple laboratory methods to directly determine sd-LDL in serum without the need for specialized equipment. The method consists of three steps: first, the precipitation of lipoproteins with magnesium harpin; second, the collection of effluent from a 100 nm filter; and third, the quantification of sd-LDL-ApoB in the effluent with an SH-SAW biosensor. There was a good correlation between ApoB values obtained using the centrifugation (y = 1.0411x + 12.96, r = 0.82, n = 20) and filtration (y = 1.0633x + 15.13, r = 0.88, n = 20) methods and commercially available sd-LDL-C assay values. In addition to the filtrate method, there was also a close correlation between sd-LDL-C and ELISA assay values (y = 1.0483x - 4489, r = 0.88, n = 20). The filtration treatment method also showed a high correlation with LDL subfractions and NMR spectra ApoB measurements (y = 2.4846x + 4.637, r = 0.89, n = 20). The presence of sd-LDL-ApoB in the effluent was also confirmed by ELISA assay. These results suggest that this filtration method is a simple and promising pretreatment for use with the SH-SAW biosensor as a rapid in vitro diagnostic (IVD) method for predicting sd-LDL concentrations. Overall, we propose a very sensitive and specific SH-SAW biosensor with the ApoB antibody in its sensitive region to monitor sd-LDL levels by employing a simple delay-time phase shifted SH-SAW device. In conclusion, based on the demonstration of our study, the SH-SAW biosensor could be a strong candidate for the future measurement of sd-LDL.

Prediction of Internal Erosion Parameters of Clay Soils Using Initial Physical Properties

This paper aims to predict the internal erosion rate index and critical shear of soils based on the initial physical properties of soils. Regression statistical analyses were employed on sixteen types of clayey soils prepared at different initial dry densities and water contents. The Hole Erosion test was conducted to determine the internal erosion parameters: the erosion rate index and the critical shear. Another set of specimens with the same initial dry unit weight and water content was remolded in the direct shear box and tested using the direct shear test to determine the shear strength parameters (i.e., the cohesion and the angle of internal friction). The various physical properties of soil (initial dry unit weight, initial water content, plastic index, liquid limit, optimum water content, maximum dry density, cohesion, and angle of internal friction) were used to develop models that predict both the erosion rate index and the critical shear. The findings show that the initial physical properties can be used to predict the erosion rate index and the critical shear. The coefficient of determination (R2) was found to be between 0.83 and 0.92 to predict the erosion rate index and between 0.85 and 0.9 to predict the critical shear. The high R2 implies that the models can be used to rate the soil erodibility in advance based on simple laboratory testing instead of time-consuming tests. Additionally, the findings give varied options for prediction depending on the availability of the soil initial physical properties.

2023 Korean Association of Urogenital Tract Infection and Inflammation guidelines for gonococcal infection.

The incidence of gonorrhea has increased significantly in recent years in the United States, especially among sexually active twenty-year-olds. Although the incidence of gonorrhea has decreased in Korea since the early 2000s, it is still common among people in their twenties. Nucleic acid amplification test (NAAT) is the most sensitive diagnostic test for detecting gonococcal infection. Gram-staining is a simple and useful laboratory test for diagnosing symptomatic male gonococcal urethritis. Although bacterial culture can be used to detect antimicrobial susceptibility, its sensitivity is lower than that of NAAT. Treatment for uncomplicated gonorrhea infection is a single intramuscular injection of ceftriaxone 500 mg. Doxycycline (100 mg twice daily for 7 days) is added if there is a possibility of co-infection with chlamydia. If ceftriaxone is difficult to use, spectinomycin 2 g can be injected intramuscularly in Korea. Patients with gonorrhea should have repeated examinations within three months at the exposure site because of a high risk of re-infection. A person diagnosed with gonorrhea should discuss the nature of the infection, the importance of informing partners, when sexual activity can resume, and how to reduce the risk of sexually transmitted infections.

Environmental complexity mitigates the demographic impact of sexual selection.

Sexual selection and the evolution of costly mating strategies can negatively impact population viability and adaptive potential. While laboratory studies have documented outcomes stemming from these processes, recent observations suggest that the demographic impact of sexual selection is contingent on the environment and therefore may have been overestimated in simple laboratory settings. Here we find support for this claim. We exposed copies of beetle populations, previously evolved with or without sexual selection, to a 10-generation heatwave while maintaining half of them in a simple environment and the other half in a complex environment. Populations with an evolutionary history of sexual selection maintained larger sizes and more stable growth rates in complex (relative to simple) environments, an effect not seen in populations evolved without sexual selection. These results have implications for evolutionary forecasting and suggest that the negative demographic impact of sexually selected mating strategies might be low in natural populations.

Comparison of Neutrophil-Lymphocyte Ratio between Diabetic Nephropathy and Without Diabetic Nephropathy in Type 2 Diabetes Mellitus at a Tertiary Care Centre

Introduction: Type 2 Diabetes mellitus is a kind of systemic disease with serious microvascular and macrovascular complications incorporate diabetic nephropathy. The Neutrophil lymphocyte ratio (NLR) is a simple and cheap laboratory tool used to predict the prognosis of many non-communicable diseases such as diabetic nephropathy. Aims: To compare neutrophil-lymphocyte ratio between type 2 diabetes mellitus with diabetic nephropathy and without diabetic nephropathy. Methods: An observational cross-sectional study was conducted at teaching hospital, Morang, Nepal. Non probability convenience sampling technique was used to collect data of 226 participants by using clinical and laboratory forms and formats. The data was analysed in SPSS version 21.00. Results: Laboratory parameters were compared between two groups. High density lipoprotein (p=0.028) and low density lipoprotein (p<0.01) and glycaemic parameters fasting blood glucose (p=0.028), postprandial blood glucose (p=0.0005) and glycated haemoglobin (p=0.007) were found to be significantly raised in diabetic nephropathy patients as compared to without diabetic nephropathy patient. Renal function tests such as estimated glomerular filtration rate (p<0.01), serum creatinine (p<0.01), urine albumin-to-creatinine ratio (p< 0.01) showed high significant differences between two groups. Blood cell count, platelets (p<0.01) and white blood cell (p<0.01) were found to have statistically significant between patients with diabetic nephropathy and without diabetic nephropathy. Majority of individuals with smoking habit fell in diabetic nephropathy group as compared with individual without diabetic nephropathy. Neutrophil lymphocyte ratio was high in diabetic nephropathy group. Conclusion: The neutrophil-lymphocyte ratio was significantly raised in type 2 diabetic patients with diabetic nephropathy. Based on above finding, neutrophil-lymphocyte ratio may be considered as a predictor and a prognostic biomarker of diabetic nephropathy.

Water Dispersible Colloidal Metal and Metal Oxide Nanoparticles Synthesis for Agarwood Inoculation: A Review

Agarwood is one of the most expensive natural products, produced from Aquilaria Spp. These plants produce agar resin through mechanical, biological, or chemical stress. Besides these, the particles having size in the range of 1-100 nm, are known as nanoparticles, have ultra-high surface area and surface plasmon resonance, can create stress on living plants when incorporated into the plant body. Adopting this concept, we intend to produce agarwood by inoculating water-dispersible metal/metal oxide nanoparticles. Therefore, we aim to synthesize water-dispersible four noble metals (Au, Ag, Pt, Pd) and five metal oxides (Fe3O4, TiO2, SnO2, MnO2, CuO) nanoparticles in aqueous colloidal states for application in biotechnology, considering the facile synthetic routes, readily available and inexpensive precursors, and stability of the products under normal laboratory conditions for an extended period, utilizing the synthesis methods of precipitation of metal/metal oxide nanoparticles from an aqueous solution, microwave and ultrasound-assisted rapid heating methods, sol-gel methods, and surfactant-assisted microemulsion methods. We believe that by applying any of these methods, water-dispersible, long-lasting colloidal metal/metal oxide nanoparticles can be synthesized using a simple laboratory setup, without the need for sophisticated tools or instruments. IUBAT Review, 6(2): 41-76