Zobrazení zdroje stránky Josephsenwagner3284

The mechanisms underlying the superb MAP and related phenomena are investigated, opening new directions for fabricating CF-based microwave absorbers with high efficiency and wide-bandwidth. Finally, the occurrence of multi-reflection phenomena of EM waves in absorbers are critically analyzed.The COVID-19 pandemic and the consequent declaration of a state of alarm have required changes throughout the entire health system and diagnostic imaging departments are no exception. In our department, these circumstances led to an immediate restructuring of the working dynamics of our group of imaging technologists that had an important role in the front lines of the battle. To ensure that these new needs were met, the staff had to be trained and distributed into different areas and working groups; moreover, new protective measures and protocols had to be adopted in the working environment. We also defined different care circuits for patients with COVID-19 and those without COVID-19, incorporating new technologies, adapting existing resources to the new scenario, and creating a circuit for the rapid diagnosis of COVID-19. This paper also provides detailed recommendations for organizing radiology departments in the case of new outbreaks of COVID-19.<br /><br /> Accurate and reproducible biomarkers are required to allow a more personalized approach to patient care. Body composition is one such biomarker affecting outcomes in a range of surgical and oncological conditions. The aim of this study is to determine the age and sex specific distribution of body composition data, based on information gathered from computed tomography (CT).<br /><br /> This prospective study used healthy subjects from the medical records linkage of the Rochester Epidemiology Project, based in Minnesota, USA. Each patient had a CT scan without intravenous contrast performed between 1999 and 2001. Quantification was performed using previously validated semi-automated in-house developed software for body composition analysis. Subcutaneous adipose tissue area, visceral adipose tissue area, intermuscular adipose tissue area and skeletal muscle area were measured and indexed to subject height. Generalized Additive Models for Location, Scale and Shape were used to assess the location, scale, and shape of each variable across age, stratified by sex. Z-scores specific to sex were assessed for each of the parameters analyzed. Age-specific z-scores were calculated using the formula Z= (Index Variable - μ)/σ or Z= (√ (Index Variable) - μ)/σ.<br /><br /> There were 692 subjects enrolled in the study. The fitted model equation was offered for each variable with values presented for μ and σ. Modelling with penalized splines was performed for VAT index, IMAT index and total adipose tissue index. Scatterplots of each variable were produced with lines of Z-scores as a visual representation.<br /><br /> This study offers comparative data to allow comparison amongst multiple populations. This will form an important reference for future research and clinical practice.<br /><br />This study offers comparative data to allow comparison amongst multiple populations. This will form an important reference for future research and clinical practice.<br /><br /> Studies evaluating the trueness of intraoral scanners (IOSs)at anatomic locations within an intracoronal preparation are lacking.<br /><br /> The purpose of this invitro study was to evaluate the trueness of digital scans obtained by IOSs at the margin and intaglio surfaces of intracoronal preparations.<br /><br /> Six IOSs (CEREC Omnicam, E4D, FastScan, iTero, TRIOS, Zfx IntraScan) were used to obtain digital scans of various intracoronal preparations. Standard tessellation language (STL)data sets obtained from a reference scanner and each IOS were superimposed, and the deviation of the digital casts was assessed at multiple measuring points along the margin and intaglio surfaces of each preparation. The Kruskal-Wallis test and multiple Mann-Whitney tests were used to detect differences in trueness (α=.05).<br /><br /> The overall median trueness values were lowest for TRIOS (23.9 μm), followed by Zfx IntraScan (24.6 μm), iTero (25.4 μm), FastScan (26.1 μm), CEREC Omnicam (26.9 μm), and E4D (77.5 μm). The greatest deviation was generally observed at the line angles between the preparation surfaces. The axiogingival line angle was the most error-prone location in the cavity preparations. An increased tendency to produce a more accurate impression was observed when the cavity had a greater width and more divergent walls.<br /><br /> The trueness of digital scans was influenced by the type of IOS and the location within a prepared cavity. The trueness decreased at the line angles between the preparation surfaces, particularly at the axiogingival line angle. Among the tested IOSs, E4D produced the least accurate digital scans.<br /><br />The trueness of digital scans was influenced by the type of IOS and the location within a prepared cavity. The trueness decreased at the line angles between the preparation surfaces, particularly at the axiogingival line angle. Among the tested IOSs, E4D produced the least accurate digital scans.<br /><br /> Marginal fit of zirconia restorations is an important criterion for their long-term success. However, in spite of the wide use of zirconia in dentistry, the relationship between marginal fit and low-temperature degradationfrom aging is unclear.<br /><br /> The purpose of this invitro study was to compare the marginal adaptation of veneered and monolithic zirconiaand metal-ceramic computer-aided design and computer-aided manufacturing (CAD-CAM) crowns before and after cementation and to evaluate the influence of artificial aging on the adaptation of zirconia crowns.<br /><br /> Seventy-two standardized dies were prepared to receive a posterior crown and randomly divided into 6 groups (n=12) as per the material and the presence or not of cement metal-ceramic, veneered zirconia, and monolithic zirconia. The zirconia groups were subjected to accelerated low-temperature degradation through hydrothermal aging in an autoclave at 131 °C and 0.17 MPa for 5 and 20 hours. A scanning electron microscopewith a magnification of×1000 was usezirconia crowns showed marginal gaps that were within an acceptable range of clinical discrepancy, regardless of cementation. Marginal adaptation was not influenced by aging. Low-temperature degradation did not lead to a significant transformation from the tetragonal to monoclinic phase.Guided tooth preparations allow clinicians to provide fixed dental prostheses for dentate patients in an efficient manner. One approach uses a digital preparation device technique where the preparation of a tooth needing a crown is guided by a device. Compared with conventional techniques, this method allows for accurate abutment preparation more efficiently and with improved quality. By controlling tooth preparation, this method preserves natural tooth structure and provides adequate clearance for the restorative material. To illustrate this technique, an adhesive minimally invasive fixed complete-mouth rehabilitation was provided by using a 3D-printed digital preparation device.There is limited research comparing nutrient removal in concentrated and dilute waste streams. Accordingly, the goal of this research was to study the effect of dilution on ammonium and potassium removal from real hydrolyzed urine using natural zeolites. The performance of two natural zeolites, clinoptilolite and chabazite, was studied and compared using batch equilibrium experiments at four dilution levels defined as urine volume divided by total solution volume (expressed as a percent) 100%, 10%, 1% and 0.1%. The adsorption behavior of other exchangeable ions, namely sodium, calcium, and magnesium, in clinoptilolite and chabazite was studied to improve the understanding of ion exchange stoichiometry. Ammonium and potassium removals were highest in undiluted urine samples treated with clinoptilolite or chabazite. This is a key finding as it illustrates the benefit of collecting undiluted urine via source separation. High removal of ammonium and potassium by clinoptilolite and chabazite was also achieved in 10% urine solutions, which are representative of water-efficient flush systems and show that nutrient recovery is possible for diluted urine as well. Chabazite showed higher ammonium and much higher potassium removal than clinoptilolite. Finally, the results showed that clinoptilolite and chabazite demonstrated stoichiometric exchange between ammonium and potassium in urine solutions with mobile cations in the zeolites.Water pollution due to microplastics (MPs) is recognized as a major anthropogenic impact. Once MPs reach the ecosystems, they are exposed to a variety of other pollutants, which can be sorbed on them, transported and eventually desorbed. In this work, we tested the hypothesis that MPs can behave as conveyors for delivering chemicals toxic to aquatic microorganisms by investigating the vector role of MPs of polyethylene terephthalate (PET), polylactic acid (PLA), polyoxymethylene (POM) and polystyrene (PS) to the macrolide antibiotics azithromycin (AZI) and clarithromycin (CLA). AZI and CLA were chosen, as they are included in the Watch List for EU monitoring concerning water policy by Decision (EU) 2018/840. MPs were loaded in contact with 500 μg/L of AZI or 1000 μg/L of CLA. Results showed that both antibiotics were sorbed on all tested MPs. The more hydrophobic AZI was sorbed in higher proportion than CLA. Both antibiotics were desorbed from MPs upon contact with water with percentages between 14.6 ± 2.6% for AZI and 1.9 ± 1.4% for CLA of the concentrations to which the MPs were initially exposed. Virgin MPs were not toxic to the cyanobacterium Anabaena sp. PCC7120. However, antibiotic-loaded MPs significantly inhibited the growth and chlorophyll content of the cyanobacterium. Most of the sorbed antibiotics became released upon contact with cyanobacterial cultures, which was the cause for the observed toxicity. Therefore, MPs can play a role as vectors of antibiotics in freshwaters systems affecting the basic trophic level of photosynthetic microorganisms.Carbon nanotubes (CNTs) have been widely used in various fields with the rapid development of nanotechnology. Pesticides have an irreplaceable role in agricultural production, which leads to their massive utilization and their inevitably penetrate into the aquatic environment. However, limited information is available regarding the impact of CNTs on the toxicity and enrichment of chiral compounds to organisms. Using zebrafish as a model to study whether the enantioselective bioaccumulation and oxidative stress of chiral pollutants may be altered in the presence of MWCNTs. Significant enantioselective bioaccumulation was observed in zebrafish with the preferential accumulation of R-(-)-indoxacarb during the 28-day bioaccumulation. The combined exposure of MWCNTs does not affect the enantioselectivity of zebrafish bioaccumulation, but increase the bioaccumulation amount of R-(-)-indoxacarb by 65%. Moreover, the average degradation half-life of indoxacarb enantiomers was 1.30 days. The indoxacarb causes oxidative stress toxicity in zebrafish liver and exhibited enantioselectivity, while the addition of MWCNTs did not significantly change the enantioselectivity of oxidative stress toxicity of indoxacarb, but enhanced the toxicity 20% with increased MWCNTs concentrations. This study suggests that the risk of the co-presence of nanomaterials and chiral pesticides in aquatic environments should be taken into consideration.