The purpose of this study is to evaluate the feasibility of using the originally developed Laser Induced Breakdown Spectroscopy (LIBS) laboratory setup for the qualitative analysis of human tooth ...tissues and tooth restorations. Plasma was induced by the infrared TEA (Transversally Excited Atmospheric) CO
2
laser in the air under atmospheric pressure. Optical emission spectra with sharp and well-resolved spectral lines and a negligibly low background were obtained. The results of the qualitative analysis showed the presence of various elements in the tooth tissues (P, Ca, and Mg), as well as trace elements within restorations such as Zn, Sn, Cu, Ag, and Hg. The estimated temperatures of plasma for composite, dentin, and amalgam were 21,000 K, 16,200 K, and 13,300 K respectively. The electron density deduced from the Stark-broadening line profiles varies from 8.5 × 10
17
cm
− 3
for amalgam, 2 × 10
18
cm
− 3
for composite, and 1.9 × 10
18
cm
− 3
for dentin. The surface of the tooth tissue was imaged with a scanning electron microscope (SEM), showing that dentin contains pores, cavities and bubbles. The results indicated that the alternative and cost-effective LIBS system can be used as a useful tool for further research on laser-induced plasma in dentistry. These insights are useful in the field of laser dentistry, where lasers are commonly utilized to treat teeth.
In DSP Architecture Design Essentials, authors Dejan Markovic and Robert W. Brodersen cover a key subject for the successful realization of DSP algorithms for communications, multimedia, and ...healthcare applications. The book addresses the need for DSP architecture design that maps advanced DSP algorithms to hardware in the most power- and area-efficient way.The key feature of this text is a design methodology based on a high-level design model that leads to hardware implementation with minimum power and area. The methodology includes algorithm-level considerations such as automated word-length reduction and intrinsic data properties that can be leveraged to reduce hardware complexity. From a high-level data-flow graph model, an architecture exploration methodology based on linear programming is used to create an array of architectural solutions tailored to the underlying hardware technology.The book is supplemented with online material: bibliography, design examples, CAD tutorials and custom software.
Closed-loop neuromodulation is essential for the advance of neuroscience and for administering therapy in patients suffering from drug-resistant neurological conditions. Neural stimulation generates ...large artifacts at the recording sites, which easily saturate traditional recording front ends. This paper presents a neural recording chopper amplifier capable of handling in-band artifacts up to 40 mVpp while preserving the accompanying small neural signals. New techniques have been proposed that solve the issues of low input impedance and electrode-offset rejection, which enable a DC input impedance of 300 MΩ and a dynamic range of 69 dB (200 Hz-5 kHz) and 78 dB (1-200 Hz). Implemented in a 40-nm CMOS process, the prototype occupies an area of 0.071 mm2/channel, and consumes 2 μW from a 1.2 V supply. The input-referred noise is 7 μV rms (200 Hz-20 kHz) and 2 μV rms (1-200 Hz). The total harmonic distortion for a 20-mV p input at 1 kHz is -74 dB. This paper improves the linearity by 14-26 dB, dynamic range by 11-28 dB, and input-impedance for chopped front ends by a factor of 11 as compared with the current state of the art, while achieving similar power and noise performance.
The possibility to utilize the antibacterial and antibiofilm potential of essential oils (EOs) in dentistry is recognized and best seen in the design of EO-based mouthwashes. The up-to-date results, ...obtained with the most commonly used formulation being consisted of thymol, eucalyptol, menthol, and methyl salicylate (Listerine), proved its efficacy against plaque and gingival inflammation. However, novel alcohol-free products remain to be further investigated. Commercially available mouthwash containing curcumin, clove oil, mentha oil, eucalyptol, thymol and tea tree oil, and the mouthwash based on ginger EO (a-zingiberene, b-bisabolene, b-sesquiphellandrene, curcumene), reduced plaque index and improved periodontal status of the patients. The plaque index was also reduced and overall healing was improved after the surgical removal of the third molar by mouthwash containing John wort oil. In addition, Cinnamomum zeylanicum EO-based mouthwash and mouthwash containing peppermint oil were efficient against stomatitis and xerostomia, respectively. In addition to beneficial effects achieved in the mouth, i.e. at the appropriate site of application, novel investigations pointed-out that EO-based mouthwashes could be recognized as efficient in the reduction of bacterial and viral aerosols. This has been shown for Listerine, and for several mouthwashes containing following active substances of plants' EO origin: a-farnesene, b-farnesene, farnesol, nerolidol, a-bulnesene, eremanthin, b-sesquiphellandrene, spiroether, cinnamylacetate, cinnamaldehyde, eugenol, menthol, and carvacrol. This finding could be of special interest, in order to be included in further clinical studies related to COVID -19 pandemic.
Background/Aim: The requirements for dental specialties and the number of specialists in each country are unique and strong indicator of the availability and affordability of primary health care for ...children and adolescents. The aim of this study was to determine the pattern, type and the extent of dental services, as well as the influence of regional factors and data on whether services are provided by a pediatric dentist or general dentist have effect on these parameters, based on information obtained from dentists providing dental care to children and youth. Material and Methods: Within the project "Program for the improvement of oral health of children and youth in the Republic of Serbia", supported by the Ministry of Health of Serbia, a research was conducted among dentists involved in dental care for children and youth in Serbia. Data collection from primary health care facilities was performed through a specially designed questionnaire. A total of 445 questionnaires were collected from dentists from 102 health centers in Serbia in the period June - October 2019. Results: There are significant differences between regions in the pattern, type and the extent of dental services. In the quantitative analysis, there are no significant differences in the type of dental services between pediatric and preventive dentistry specialists and general dentists. Conclusions: The data from the conducted research speak in favor of a large daily workload of dentists who deliver oral health care for children and youth in Serbia. Additional multifactorial analysis, which includes epidemiological data from the region, but also environmental, demographic and cultural parameters of oral health could be the basis for improving the provision of preventive dental and preventive oral care
Background/Aim: Autism spectrum disorder (ASD) is pervasive neurodevelopmental condition with raising prevalence over the last decades. Oral health related problems arise mostly due to challenging ...behavior, communication limitation, and resistance to receiving dental treatment. The aim of this retrospective study was to investigate the frequency, quality and type of dental care during routine appointments and under general anesthesia (GA) in persons with ASD. Matreial and Methods: The data were obtained in retrospective cross-sectional study by analyzing patients' records from the central electronic database of the Clinic for Dentistry of Vojvodina. Demographic, medical and dental data were analyzed employing Mann Whitney U test, Kruskal Wallis test and CATREG regression analysis. Results: A total of 51 patients from 4.2-47.6 years of age had an average of 13.2 ±13.5 dental appointments, with 2.27±4.23 treatments done under GA in a period of 7 years. The average number of restored teeth was 3.64±4.42 and 4.64±5.95 teeth were extracted. Only 21.5% of participants regularly attended scheduled appointments. Patients who started oral health care earlier had more teeth restored and extracted during RDT, and were less subjected to treatment under GA. Conclusions: Dental services to patients with ASD are commonly limited to more radical approach comprising multiple teeth extractions and repeated treatment under GA. It is of utmost importance to tailor comprehensive plan for dental care provision in individuals with ASD at earliest possible age.
Chopping is an effective way to mitigate transistor flicker noise in biosignal amplifiers. However, chopping creates a ripple at the output of the amplifier, which is due to the upmodulated amplifier ...offset and flicker noise. Many techniques have been suggested in the literature to reduce these ripples. This brief presents a ripple-reduction technique that is far simpler than previous techniques, yet effective and area efficient while consuming no additional power. Simulations using a 65-nm complementary metal-oxide-semiconductor process show that the output ripples are attenuated by 78 dB, whereas all other performance parameters of the amplifier remain unchanged.
Closed-loop neuromodulation is an essential function in future neural implants for delivering efficient and effective therapy. However, a closed-loop system requires the neural-recording front-end to ...handle large stimulation artifacts-a feature not supported by most state-of-the-art designs. In this paper, we present a neural-recording front-end that has an input range of ±50 mV and can be used in closed-loop systems. The proposed front-end avoids the saturation due to stimulation artifacts by employing a voltage-controlled oscillator (VCO) to directly convert the input signal into the frequency domain. The VCO nonlinearity is corrected using area-efficient foreground polynomial correction. Implemented in a 40-nm CMOS process, the design occupies 0.135 mm 2 with an analog power of 3 μW and a digital switching power of 4 μW. It achieves ten times higher linear input range than prior art, and 79-dB spurious-free dynamic range at peak input, with an input-referred noise of 5.2 μV rms across the local-field-potential band of 1-200 Hz. With on-chip subhertz high-pass filters realized by duty-cycled resistors, the front-end also eliminates the need of off-chip dc-blocking capacitors.
Background/Aim: Understanding the composition of bacteria in infected root canals is important for ameliorating the treatment strategies that lead to the elimination of pathogens and infection ...control, but also prevent reinfection. Aim of this study was to investigate microbial composition of primary infected root canals with apical periodontitis of young permanent teeth, originating form school children in Serbia, and its association with clinical symptoms. Material and Methods: To determine the bacterial composition of infected root canals in children, 35 endodontic samples were obtained. The identification of cultured bacteria was performed by MALDI-TOF MS analysis. The presence or absence of clinical symptoms were recorded. Results: Facultative anaerobes were 2,2 times more frequent than obligate anaerobes. The most common facultative anaerobes belonged to following genera, Streptococcus (58 isolates), Actinomyces (10) and Enterococcus (8), while predominant obligate anaerobes, belonged to genera Veillonella (15), Prevotella (9) and Fusobacterium (8). The most common clinical isolates recovered from infected root canals with symptomatic apical periodontitis were Veillonella parvula (10) and Fusobacterium nucleatum (7), while from the asymptomatic ones, they were Streptococcus mitis/Streptococcus oralis (5). Prevalence of Parvimonas micra, Prevotella buccae and Streptococcus constellatus within the root canals might be associated to clinical symptoms. Conclusions: Species of genera Streptococcus and Veillonella were the most common isolates from primary infected root canals with apical periodontitis in Serbian school children. Facultative anaerobes were predominant over obligate anaerobes. The prevalence of obligate anaerobes was much higher in symptomatic compared to asymptomatic root canal infections. No specific bacterial strain might be associated to a single examined clinical symptom (pain, tenderness to percussion or swelling), but majority of the strains are associated to all of the examined three symptoms.
Irreversible degradation of quercetin and rutin, dissolved in methanol and
water, induced by continuous UV-irradiation from two different sub-ranges
(UV-B and UV-C) has been studied in this work. The ...degradation of both
flavonoids is related to formation of UV-induced degradation products: both
processes follow first-order kinetics. The degradation and products formation
rate constants are both dependent on the involved UV-photons energy input in
both solvents.
nema
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