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Background: Facial expression muscles serve a fundamental role in the orofacial system, significantly influencing the overall health and well-being of an individual. They are essential for performing basic functions such as speech, chewing, and swallowing. The purpose of this study was to determine whether surface electromyography could be used to evaluate the health, function, or dysfunction of three facial muscles by measuring their electrical activity in healthy people. Additionally, to ascertain whether pattern recognition and artificial intelligence may be used for tasks that differ from one another. Results: The study included 24 participants and examined three muscles (m. Orbicularis Oris, m. Zygomaticus Major, and m. Mentalis) during five different facial expressions. Prior to thorough statistical analysis, features were extracted from the acquired electromyographs. Finally, classification was done with the use of logistic regression, random forest classifier and linear discriminant analysis. A statistically significant difference in muscle activity amplitudes was demonstrated between muscles, enabling the tracking of individual muscle activity for diagnostic and therapeutic purposes. Additionally other time domain and frequency domain features were analyzed, showing statistical significance in differentiation between muscles as well. Examples of pattern recognition showed promising avenues for further research and development. Conclusion: Surface electromyography is a useful method for assessing the function of facial expression muscles, significantly contributing to the diagnosis and treatment of oral motor function disorders. Results of this study show potential for further research and development in this field of research. [ABSTRACT FROM AUTHOR]

Background/Aim: Human saliva offers many advantages over blood-based biochemical assays, therefore, becomes the biological fluid of interest. Once antiseptic solutions react with saliva, both fluids undergo significant changes of their biophysical properties, consequently, those changes have an impact on their principal function.

Textile-based microfluidic biosensors represent an innovative fusion of various multidisciplinary fields, including bioelectronics, material sciences, and microfluidics. Their potential in biomedicine is significant as they leverage textiles to achieve high demands of biocompatibility with the human body and conform to the irregular surfaces of the body. In the field of microfluidics, fabric coated with hydrophobic materials serves as channels through which liquids are transferred in precise amounts to the sensing element, which in this case is a biosensor. This paper presents a condensed overview of the current developments in textile-based microfluidics and biosensors in biomedical applications over the past 20 years (2005–2024). A literature search was performed using the Scopus database. The fabrication techniques and materials used are discussed in this paper, as these will be key in various modifications and advancements in textile-based microfluidics. Furthermore, we also address the gaps in the application of textile-based microfluidic analytical devices in biomedicine and discuss the potential solutions. Advances in textile-based microfluidics are enabled by various printing and fabric manufacturing techniques, such as screen printing, embroidery, and weaving. Integration of these devices into everyday clothing holds promise for future vital sign monitoring, such as glucose, albumin, lactate, and ion levels, as well as early detection of hereditary diseases through gene detection. Although most testing currently takes place in a laboratory or controlled environment, this field is rapidly evolving and pushing the boundaries of biomedicine, improving the quality of human life. [ABSTRACT FROM AUTHOR]

A procedure is developed for producing basic electronic components utilizing materials sourced from discarded orange, grapefruit, lemon, apple, banana, potato, and carrot peels. Initially, these materials undergo dehydration, followed by a meticulous pulverization process to obtain fine powder. Natural adhesives like water, honey, sugar, starch, and gelatin are employed to interconnect the materials. Formed substrates are characterized using Scanning Electron Microscopy, Energy Dispersive X‐ray Spectroscopy, and an optical profilometer. Furthermore, the relative permittivity of the materials is determined. Three distinct types of substrates, derived from the aforementioned peels, are crafted in varying dimensions. Substrates measuring 4 cm × 2.5 cm host interdigital capacitive sensors, whereas larger 6 cm × 3.5 cm substrates accommodate inductor‐capacitor (LC) sensors. Each of the six samples undergoes individual dry testing, while LC sensors are additionally tested with the post‐application of artificial saliva and mouthwash liquids. The sensor's characterization involves measurement of impedance and phase angle for all samples. Capacitance is additionally measured for capacitors, and inductance for LC circuits. These assessments are carried out within the frequency range spanning from 1 MHz to 400 MHz. The objective is the development of fully functional electronic components, derived from discarded edible items, fostering sustainable practices, and finding applications in biomedicine. [ABSTRACT FROM AUTHOR]

Diagnosing oral diseases at an early stage may lead to better preventive treatments, thus reducing treatment burden and costs. This paper introduces a systematic design of a microfluidic compact disc (CD) consisting of six unique chambers that run simultaneously from sample loading, holding, mixing and analysis. In this study, the electrochemical property changes between real saliva and artificial saliva mixed with three different types of mouthwashes (i.e. chlorhexidine-, fluoride- and essential oil (Listerine)-based mouthwashes) were investigated using electrical impedance analysis. Given the diversity and complexity of patient's salivary samples, we investigated the electrochemical impedance property of healthy real saliva mixed with different types of mouthwashes to understand the different electrochemical property which could be a foundation for diagnosis and monitoring of oral diseases. On the other hand, electrochemical impedance property of artificial saliva, a commonly used moisturizing agent and lubricant for the treatment of xerostomia or dry mouth syndrome was also studied. The findings indicate that artificial saliva and fluoride-based mouthwash showed higher conductance values compared to real saliva and two other different types of mouthwashes. The ability of our new microfluidic CD platform to perform multiplex processes and detection of electrochemical property of different types of saliva and mouthwashes is a fundamental concept for future research on salivary theranostics using point-of-care microfluidic CD platform. [ABSTRACT FROM AUTHOR]

Nitinol (NiTi) alloy is a widely used material for the production of orthodontic archwires. Its corrosion behavior in conditions that exist in the oral cavity still remains a great characterization challenge. The motivation behind this work is to reveal the influence of commercially available mouthwashes on NiTi orthodontic archwires by performing non-electrochemical corrosion tests and quantifying the changes in the nanotopography of commercially available NiTi orthodontic wires. In this study, we examined the behavior of NiTi alloy archwires exposed for 21.5 days to different corrosive media: artificial saliva, Eludril®, Aquafresh®, and Listerine®. The corrosion was characterized by contact mode atomic force microscopy (AFM) before and after the corrosion tests. A novel analysis methodology was developed to obtain insight into locations of material gain or material loss based on standard surface roughness parameters Sa, Sdr, Ssk, and S10z. The developed methodology revealed that fluoride-containing mouthwashes (Aquafresh® and Listerine®) dominantly cause material loss, while chloride-containing mouthwash (Eludril®) can cause both material loss and material gain. The sample exposed to artificial saliva did not display significant changes in any parameter. [ABSTRACT FROM AUTHOR]

Drug delivery systems are engineered platforms for the controlled release of various therapeutic agents. This paper presents a conductive gold leaf-based microfluidic platform fabricated using xurography technique for its potential implication in controlled drug delivery operations. To demonstrate this, peppermint and eucalyptus essential oils (EOs) were selected as target fluids, which are best known for their medicinal properties in the field of dentistry. The work takes advantage of the high conductivity of the gold leaf, and thus, the response characteristics of the microfluidic chip are studied using electrochemical impedance spectroscopy (EIS) upon injecting EOs into its micro-channels. The effect of the exposure time of the chip to different concentrations (1% and 5%) of EOs was analyzed, and change in electrical resistance was measured at different time intervals of 0 h (the time of injection), 22 h, and 46 h. It was observed that our fabricated device demonstrated higher values of electrical resistance when exposed to EOs for longer times. Moreover, eucalyptus oil had stronger degradable effects on the chip, which resulted in higher electrical resistance than that of peppermint. 1% and 5% of Eucalyptus oil showed an electrical resistance of 1.79 kΩ and 1.45 kΩ at 10 kHz, while 1% and 5% of peppermint oil showed 1.26 kΩ and 1.07 kΩ of electrical resistance at 10 kHz respectively. The findings obtained in this paper are beneficial for designing suitable microfluidic devices to expand their applications for various biomedical purposes. [ABSTRACT FROM AUTHOR]

bioNEMS/MEMS has emerged as an innovative technology for the miniaturisation of biomedical devices with high precision and rapid processing since its first R&D breakthrough in the 1980s. To date, several organic including food waste derived nanomaterials and inorganic nanomaterials (e.g., carbon nanotubes, graphene, silica, gold, and magnetic nanoparticles) have steered the development of high-throughput and sensitive bioNEMS/MEMS-based biosensors, actuator systems, drug delivery systems and implantable/wearable sensors with desirable biomedical properties. Turning food waste into valuable nanomaterials is potential groundbreaking research in this growing field of bioMEMS/NEMS. This review aspires to communicate recent progress in organic and inorganic nanomaterials based bioNEMS/MEMS for biomedical applications, comprehensively discussing nanomaterials criteria and their prospects as ideal tools for biomedical devices. We discuss clinical applications for diagnostic, monitoring, and therapeutic applications as well as the technological potential for cell manipulation (i.e., sorting, separation, and patterning technology). In addition, current in vitro and in vivo assessments of promising nanomaterials-based biomedical devices will be discussed in this review. Finally, this review also looked at the most recent state-of-the-art knowledge on Internet of Things (IoT) applications such as nanosensors, nanoantennas, nanoprocessors, and nanobattery. [ABSTRACT FROM AUTHOR]

The aim of this study was to tackle the topic of appropriate recommendations for artificial-saliva and mouthwash usage. The contact angle, pH, and conductivity of two artificial saliva solutions, four mouthwashes, and their mixtures on enamel, glass-ionomer, and composite dental materials were measured. The measurements were conducted with a MATLAB algorithm to minimize human error. The obtained values for the contact angle were in the range from 7.98° to 52.6°, and they showed completely nonlinear and nonuniform behavior for all investigated liquids and on all investigated substrates. Results reveal statistically significant differences among all tested liquids on all investigated substrates (p < 0.05). pH values ranged from 1.54 to 7.01. A wide range of conductivity values were observed, from 1205µS/cm in the saliva-stimulating solution to 6679 mS/cm in the artificial saliva. Spearman's test showed a moderate positive correlation between the pH and conductivity of the tested fluids (R = 0.7108). A comparison of the data obtained using Image J software and the MATLAB algorithm showed consistency, not exceeding 5% error. When an experiment uses human material and bioactive materials THAT are used in biomedicine as substrates, an additional definition of protocols is highly recommended for future research on this topic. [ABSTRACT FROM AUTHOR]

Polycrystalline samples of NaCo2−xCuxO4 (x = 0, 0.01, 0.03, 0.05) were obtained from powder precursors synthesized by a mechanochemically assisted solid-state reaction method (MASSR) and a citric acid complex method (CAC). Ceramic samples were prepared by pressing into disc-shaped pellets and subsequently sintering at 880 °C in an argon atmosphere. Effects of low concentrations of Cu doping and the above-mentioned synthesis procedures on the thermoelectric and mechanical properties were observed. The electrical resistivity (ρ), the thermal conductivity (κ) and the Seebeck coefficient (S) were measured simultaneously in the temperature gradient (ΔT) between the hot and cold side of the sample, and the figure of merit (ZT) was subsequently calculated. The ZT of the CAC samples was higher compared with the MASSR samples. The highest ZT value of 0.061 at ΔT = 473 K was obtained for the sample with 5 mol% of Cu prepared by the CAC method. The CAC samples showed better mechanical properties compared to the MASSR samples due to the higher hardness of the CAC samples which is a consequence of homogeneous microstructure and higher density obtained during sintering of these samples. The results confirmed that, besides the concentration of Cu, the synthesis procedure considerably affected the thermoelectric and mechanical properties of NaCo2O4 (NCO) ceramics. [ABSTRACT FROM AUTHOR]

In this paper, we propose a microfluidic approach for measuring pH, dissolved oxygen (O2), and carbon dioxide (CO2) in human saliva. The proposed innovative method combines the advantages of a microfluidic approach, i.e., small amounts of samples and reagents and precise control of the experimental conditions, with rapid measurements of significant parameters of saliva. The novel design of a microfluidic chip with integrated commercially available PreSens sensors was used for examining the effect of Chlorhexidine on artificial saliva (AS), stimulated saliva (SS), and non-stimulated saliva (NSS). The measurement results showed that for persons with an initially low saliva pH, the use of Chlorhexidine increased the pH, and afterward, the pH value returned to the initial value or higher. However, measurements of volunteers with initial pH close to neutral showed that Chlorhexidine reduced the pH value, increasing the risk of erosion and demineralization. In conclusion, the proposed methodology showed potential for precise measurements of pH in saliva samples; however, further research is required to examine the influence of the sample collection method on the amounts of O2 and CO2 in saliva. [ABSTRACT FROM AUTHOR]

Miniaturization of different measurement processes and a scaled-down approach open the possibility for rapid measurements with the small amounts of samples and reagents into a compact platform with integrated sensors and different measuring components. In this paper, we report a microfluidic approach for measurements of salivary pH, dissolved O2, and CO2 during chewing xylitol gum. The study was done with the samples of 30 healthy volunteers who were chewing a xylitol gum, and the measurements were performed in the microfluidic (MF) chip with integrated commercial PreSens sensors. Xylitol exhibited a significant effect on the pH of saliva in terms of its initial drop, which was the most significant between the 5th and 10th minutes. The effect of xylitol on the amount of oxygen and carbon dioxide in saliva cannot be confirmed. The employed microfluidic platform was shown to be applicable and effective in the analysis of salivary biomarkers relevant to caries development. [ABSTRACT FROM AUTHOR]

Demands for circuits with higher density in modern electronics have imposed the necessity for electronic components with compact size, high frequency operational range, high efficiency and cost-effectiveness. This requires the new design of electronic components, such as multi-phase coupled inductor with ferrite Ni-Zn core which is studied in this paper. Printed circuit board (PCB) technology was used to develop six symmetrical conductive copper coils, while specially designed innovative ferrite core has been mounted through the PCB, to create a compact component. For ferrite core, two Ni-Zn materials denoted with C2025 and CN20 were used. Testing of the component has been performed using the following characterization methods: (a) structural characterization using scanning electron microscope; (b) electrical characterization using Impedance analyzer; and (c) mechanical characterization using Nanoindenter. It can be concluded from tests carried out (load-displacement curves and hardness module) that designed and manufactured component can be exposed to mechanical stress and vibrations and can be used in applications such as DC/DC convertors. [ABSTRACT FROM AUTHOR]

Dental floss is an oral hygiene product used to remove food and plaque in places where toothbrushes cannot reach. Even though over the years since its introduction some research in suitable materials has been performed, thread cracking and wear can still compromise efficiency. The aim of this study was to examine the morphological properties of four different commercially available dental floss types before and after use. For that purpose, scanning electron microscopy and optical microscopy were used to assess the flosses before and after use, and tension testing was performed to determine any degradation in the floss performance after utilization. The analyzed floss samples verify the hypothesis that the properties of the floss need to be known in depth, before recommending a specific type to patients for daily use in all clinical indications. [ABSTRACT FROM AUTHOR]

Around 8000 years ago, throughout the Neolithic world a new type of artefact appeared, small spoons masterly made from cattle bone, usually interpreted as tools, due to their intensive traces of use. Contrary to those interpretations, the small dimensions of spoons and presence of intensive traces of use led us to the assumption that they were used for feeding babies. In order to test that assumption we compared 2230 marks on three spoons from the Neolithic site of Grad-Starčevo in Serbia (5800−5450 cal BC) with 3151 primary teeth marks produced experimentally. This study has shown that some of the marks on spoons were made by primary teeth, which indicate their usage in feeding babies. The production of a new type of artefact to feed babies is probably related to the appearance of a new type of weaning food, and the abundance of spoons indicates that new baby gruels became an important innovation in prehistoric baby-care. [ABSTRACT FROM AUTHOR]