Search Results (19)

This research explores the influence of air pressure on the surface roughness of ST-37 steel plates in the sandblasting process. Sandblasting is a common method in industry to enhance material surfaces. This study focuses on the effects of varying air pressure on surface roughness, crucial for achieving the desired quality. ST-37 steel plates, known for their strength and versatility, are used in various applications. The research involves a sandblasting process with different air pressures, analyzing surface roughness and contact area. The results indicate a direct correlation between increased air pressure, surface roughness, and contact area. Full article

This paper presents a method for monitoring food freshness and quality through the early detection of biogenic amines, which are indicators of food spoilage/degradation. The urge to monitor food quality has led to a growing interest in the detection of toxic compounds, such as biogenic amines (BAs), as chemical indicators of food degradation by using different bioanalytical tools. The bioanalytical platform includes several parts and modules useful for food hazard evaluation. This paper presents how electrochemical and spectrometric detection works for biogenic amine monitoring in food and how the communication interface provides useful data. Full article

Flexible screen-printed electrodes (SPE) were modified in a simple manner with different composite nanomaterials based on carbon allotropes, polymers, and metallic nanoparticles, for amperometric detection of nitrites in soil. Multiwalled carbon nanotubes (MWCNT), chitosan (CS), silver nanoparticles (AgNPs), 1,8-diaminonaphthalene (1,8-DAN), and a sol-gel (SG) matrix were used for modification of the carbon paste working electrodes. Sensitive and selective detection of nitrite was achieved by using a MWCNT-CS-modified sensor, in acetate buffer at pH 5, at an applied potential of 0.58 V vs. Ag/AgCl. The MWCNT-CS-based sensor displayed a specific sensitivity of 204.4 mA·M⁻¹·cm⁻², with a detection limit of 2.3 µM (S/N = 3) in a linear range up to 1.7 mM, showing good stability, reproducibility, and selectivity towards other interfering species. A miniaturized portable system using the developed flexible electrochemical MWCNT-CS-based sensors was dedicated for the detection of nitrite in different samples of soil solutions extracted by using suction lysimeters. Full article

Wireless sensor network is a network consisting of many sensor nodes that function to scan certain phenomena around it. WSN has quite a large problem in the form of delay and data loss which results in low WSN performance. This study aims to improve WSN performance by developing a cluster-based routing protocol. The cluster formation is carried out in several stages. The first is the formation of the cluster head which is the channel reference to be used by node members by means of probability calculations. The second determines the closest node using the Euclidean approach when looking for the closest member of the node to the cluster head. The third is determination of the node members by means of single linkage grouping by looking for proximity to CH. The performance of the proposed MCCH method is then tested and evaluated using QoS parameters. The results of this research evaluation use QoS parameters for testing the MCCH method, channel 1 throughput 508.165, channel 2 throughput 255.5661, channel 3 throughput 479.8289, channel 4 throughput 646.5618. Full article

Highly electrosensitive platforms have been developed using different nanocomposite materials based on carbon allotropes and different metallic nanoparticles for determination of nitrite and biogenic amines (BAs). The nitrification process occurred in soil represents an important source of pollution. The nitrification consists in biological oxidation of the relatively immobile ammonium (NH₄⁺) to highly mobile nitrate, via nitrite. This process is carried out mainly by the ammonia–oxidizing bacteria (Nitrosomonas sp. and Nitrobacter sp.) present in the soil microbial population [1,²]. The nitrite contamination of ground and surface waters represents the major concern associated with the nitrification process. Additionally, the growing needs for food and environmental safety has led to an increase in research for the detection of biogenic amines (BAs) in recent years. Despite the fact that BAs are increasingly present in food and beverages, causing toxic effects in the body, legislation that limits their presence in food chains needs to be updated, thus requiring sensitive tools for their detection [³,⁴]. Miniaturized analytical tools have been developed based on nanocomposite materials obtained through combination of different carbon allotrope materials (nanoribbons, nanotubes—single and multiwalled—and nanofibers) with metallic nanoparticles (Ag, Au-Ag, Pt, Cu). Thus, carbon based screen-printed electrodes (SPE) were chemically modified with the obtained nanocomposite materials and further characterized using different electrochemical techniques. In order to allow a selective and sensitive determination of analytes, an electropolymerized film was deposed on the modified sensors. For BAs determination were realized with two configurations of biosensors, a bienzymatic one consisting in immobilization of diamine oxidase (DAO) and horseradish peroxidase (HRP) onto the modified sensors, and, respectively, a mono-enzymatic system based on immobilization of DAO onto the modified sensors. It was taken into account that the charge of carbon-based nanomaterials on the surface of the sensors should not exceed 5%, in order to ensure a low based current. Morpho-structural and electrochemical characterization studies of the modified SPEs have been performed in order to achieve a high sensitivity and selectivity of detection, applying a low overvoltage. The co-polymeric film ensured a better stability of the nanocomposite material layers at the electrode surface and an optimal matrix for enzymes immobilization. Optimization of the nanocomposite-based sensors were performed, and finally detection of biogenic amines was carried out using biosensors based on single-walled carbon nanotubes and Pt nanoparticles, while nitrite determination was performed using multi-walled carbon nanotubes and AgNP modified sensors at applied potentials between −0.45 and +0.6 V vs. Ag/AgCL. The developed sensors and biosensors showed good sensitivities of nitrite and BAs detection. Although the enzyme DAO has a low enough activity to catalyze the oxidation of amine of interest, the detection limits were lowered due to the electrocatalytic activity of nanocomposite materials and the HRP enzyme used. Full article

Grapes’ infection with the fungi Botrytis cinerea is one of the major causes of economic loss in the winemaking sector worldwide. The laccase activity of grapes is considered an appropriate indicator of this type of fungal infection, and enzymatic activity higher than 3 U/mL indicates a high risk of irreversibly damaged grape must due to enzymatic browning. This work describes a fast test for the measurement of laccase activity based on a dual optical and electrochemical detection method. A paper sensor impregnated with the enzymatic substrate dye 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) provides a semi-quantitative optical measurement. While the paper sensor can be used independently, when combined with a screen-printed electrode and amperometry measurements, it enables the quantitative detection of laccase activities down to 0.4 U/mL in only 5 min. The method was applied for monitoring the artificial infection of white, rosé, and red grapes with different strains of Botrytis cinerea. The results were confirmed by parallel analysis using the spectrophotometric method of laccase activity determination based on syringaldazine. The influence of the fungal strain and type of grape on laccase activity levels is reported. The demonstrated robustness, simplicity, and versatility of the developed method make it ideal for application on-site in the vineyard or at grape processing points. Full article

Sensitive, stable and robust electrochemical sensors have been designed through modification
of the working electrodes with different complex matrices based on carbon nanomaterials and
metallic nanoparticles. Therefore, screen-printed electrodes were modified with complex matrices of
hybrid nanomaterials using physical deposition or entrapment in polymeric film. [...]  Full article

Despite the negative role of IT in digital addiction development, IT may have a positive role in dealing with digital addiction. The present study undertakes a systematic literature review to explore the state of play and the trend regarding the use of IT in digital addiction research. Using predefined keywords, the Scopus database was searched for relevant literature published from 2017 to 2020. The initial search found 1655 papers. Six stages of study selection were completed using a set of inclusion and exclusion criteria. The study selection and quality assessment process were applied, then 15 papers were selected for further review. The results show that addiction detection using IT is the most researched topic in digital addiction research. The most commonly used IT in the selected studies are AI methods and biosignal recording systems. Various approaches in detection, prevention, and intervention are suggested in the selected studies. The advantages and limitations of each approach are discussed. Based on these results, some future research directions are suggested. Full article

Over the last few years, soil sealing has been recognized as one of the major threats in terms of soil degradation and loss of ecosystem services. Although many efforts have been promoted to increase the awareness of safeguarding soil for stakeholders, its value as a non-renewable resource as well as soil-related services in urban ecosystems is not implemented enough in urban planning and policies. Due to the spatially explicit component and the geographical scale of soil sealing, mapping and quantifying the number of sealed surfaces is crucial. The aim of this paper was to estimate and geovisualize the soil sealed in the city of Padua (Italy) at a very detailed scale, testing the use of the Biotope Area Factor (BAF) index. Moreover, the paper aimed to simulate an alternative mitigation scenario in a specific study area of the city. Spatial analysis was performed testing the BAF index in a Geographic Information Sistem (GIS) environment and using aerial ortho-photos at very high resolution. The results show different values of the BAF index for all four neighborhoods from 0.35 to 0.69. In the mitigation scenario, the value of the BAF index was improved using a measure of green roofs. In conclusion, the paper provides an insightful case study for enriching the debate about soil sealing and gives scientific support for sustainable urban planning. Full article

Electrochemical sensors and biosensors have been proposed as fast and cost effective analytical tools, meeting the robustness and performance requirements for industrial process monitoring. In wine production, electrochemical biosensors have proven useful for monitoring critical parameters related to alcoholic fermentation (AF), malolactic fermentation (MLF), determining the impact of the various technological steps and treatments on wine quality, or assessing the differences due to wine age, grape variety, vineyard or geographical region. This review summarizes the current information on the voltamperometric biosensors developed for monitoring wine production with a focus on sensing concepts tested in industry-like settings and on the main quality parameters such as glucose, alcohol, malic and lactic acids, phenolic compounds and allergens. Recent progress featuring nanomaterial-enabled enhancement of sensor performance and applications based on screen-printed electrodes is emphasized. A case study presents the monitoring of alcoholic fermentation based on commercial biosensors adapted with minimal method development for the detection of glucose and phenolic compounds in wine and included in an automated monitoring system. The current challenges and perspectives for the wider application of electrochemical sensors in monitoring industrial processes such as wine production are discussed. Full article

Systemic lupus erythematosus (SLE) is an autoimmune disease with variable clinical expression. It is a potentially devastating condition affecting mostly women and leading to clinically unpredictable outcomes. Remission and flares may, in fact, alternate over time and a mild involvement limited to few articular sites may be followed by severe and widespread organ damage. SLE is the prototype of any autoimmune condition and has, for this reason, attracted the interest of basic immunologists. Therapies have evolved over time and clinical prognosis has, in parallel, been improved. What clinicians still lack is the possibility to use biomarkers of the disease as predictors of outcome and, in this area, several studies are trying to find solutions. Circulating autoantibodies are clearly a milestone of clinical research and the concrete possibility is to integrate, in the future, classical markers of activation (like C3) with target organ autoantibodies. Anti-dsDNA antibodies represent a basic point in any predictive attempt in SLE and should be considered the benchmark for any innovative proposal in the wide field of target organ pathologies related to SLE. DNA is part of the nucleosome that is the basic unit of chromatin. It consists of DNA wrapped around a histone octamer made of 2 copies each of Histone 2A, 2B, 3, and 4. The nucleosome has a plastic organization that varies over time and has the potential to stimulate the formation of antibodies directed to the whole structure (anti-nucleosome) or its parts (anti-dsDNA and anti-Histones). Here, we present an updated review of the literature on antibodies directed to the nucleosome and the nucleosome constituents, i.e., DNA and Histones. Wetriedto merge the data first published more than twenty years ago with more recent results to create a balanced bridge between old dogma and more recent research that could serve as a stimulus to reconsider mechanisms for SLE. The formation of large networks would provide the chance of studying large cohorts of patients and confirm what already presented in small sample size during the last years. Full article