An Optical System to Monitor the Displacement Field of Glass-fibre Posts Subjected to Thermal Loading

Endocanalar posts are necessary to build up and retain coronal restorations but they do not reinforce dental roots. It was observed that the dislodgement of post-retained restorations commonly occurs after several years of function and long-term retention may be influenced by various factors such as temperature changes. Temperature changes, in fact, produce micrometric deformations of post and surrounding tissues/materials that may generate high stress concentrations at the interface thus leading to failure. In this study we present an optical system based on the projection moiré technique that has been utilized to monitor the displacement field of endocanalar glass-fibre posts subjected to temperature changes. Measurements were performed on forty samples and the average displacement values registered at the apical and middle region were determined for six different temperature levels. A total of 480 displacement measurements was hence performed. The values of the standard deviation computed for each of the tested temperatures over the forty samples appear reasonably small which proves the robustness and the reliability of the proposed optical technique. The possible implications for the use of the system in the applicative context were discussed

Roughness analysis on composite materials (Microfilled, nanofilled and silorane) after different finishing and polishing procedures

The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting surface roughness. In the present study, 156 samples were realized with three composite materials,-microfilled, nanofilled and silorane-, and treated with different finishing and polishing procedures. Profilometric analyses were carried out on the samples’ surface, the measured roughness values were submitted to statistical analysis. A complete factorial plan was drawn up and two-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of roughness: (i) material; (ii) polishing/finishing procedure. Tukey post-hoc test was also conducted to evaluate any statistically significant differences between the material/procedure combinations. The results show that the tested materials do not affect the resulting surface quality but roughness values depend on the finishing/polishing procedure adopted. The procedures that involve: (a) the finishing with medium Sof-Lex discs and (b) the finishing with two tungsten carbide multi-blade milling cutters Q series and UF series are those that allow the lowest values of roughness to be obtained

Heterogeneity and penetration of HIV-1 non-subtype B viruses in an Italian province: Public health implications

SUMMARYThis study assessed changes in prevalence and distribution of HIV-1 non-subtype B viruses in Italian and immigrant patients over two decades in a province in Italy. All HIV-positive patients who underwent genotypic resistance testing were selected. Prevalence of non-subtype B viruses in 3-year periods was calculated. All sequences of non-subtype B and those provided by REGA as unassigned were analysed for phylogenetic relationships. In total, 250/1563 (16%) individuals were infected with a non-subtype B virus. Prevalence increased over time, reaching a peak (31·5%) in 2004–2006. In Italian patients, the most frequent subtypes were B (92·5%) and F1 (4%). F1 subtype was also prevalent in patients from South America (13·6%); in patients of African origin, CRF02_AG (54·9%) and G (12·3%) were the most frequent. HIV-1 non-subtype B infections in Italians were mostly found in patients who acquired HIV sexually. A phylogenetic relationship between F subtypes in Italian and representative HIV-1 sequences from Brazil was found. C subtypes in Italians were phylogenetically related to subtypes circulating in Brazil. Inter-subtype recombinants were also found in the latest years. The HIV-1 epidemic in Brescia province evolved to the point where about 1/3 patients recently diagnosed harboured non-B HIV subtypes. The distribution of HIV-1 non-B subtypes in Italian patients resembled that in South American patients and phylogenetic relatedness between some Italian and South American HIV-1 strains was found. The possible epidemiological link between these two populations would have been missed by looking only at risk factors for HIV acquisition declared by patients. The evidence of inter-subtype recombinants points to significant genetic assortment. Overall our results support phylogenetic analysis as a tool for epidemiological investigation in order to guide targeted prevention strategies

Tocilizumab and corticosteroids for covid-19 treatment in elderly patients

Background. The mortality rate for coronavirus disease-19 (COVID-19) increases with age. Some anti-inflammatory drugs such as tocilizumab or steroids have been proposed for the treatment of severe disease; however, few data are available in the elderly. Methods. A retrospective case-series of patients hospitalized between March 1st and June 15th, 2020 with confirmed COVID-19 by RT-PCR testing on throat/nasopharyngeal swabs and age ≥ 65 years was analysed. Patients were retrospectively divided into three groups according to the chosen treatment [standard of care (SOC), tocilizumab or corticosteroids] and patient characteristics and occurrence of adverse events were compared among groups. Results. Overall, 206 patients were included, 148 treated with standard of care, 42 with steroids and 16 with tocilizumab. Patients treated with steroids or Tocilizumab presented more frequently with fever (p = .003), dyspnea (p < .001), bilateral opacities/infiltrates at chest X-ray (p =.026) or CT-scan (p = .020), and more frequently required non-invasive/invasive ventilation (p < .001). Crude mortality was 27%, without differences among groups (p = .074). No specific adverse events were observed during/after the administration of steroids or tocilizumab; however, a trend towards an increased risk of secondary infections was described compared to SOC (p = .097). At multivariate logistic regression, only tocilizumab administration was an independent predictor of secondary infections (aOR = 6.72, 95% CI = 1.43-31.39, p = .015). Conclusions. Tocilizumab and corticosteroid could have a possible role for severe form of pneumonia in course of COVID-19 also in elderly patients, even if great attention to the monitoring of infectious complications should be paid in this special population

Effect of workpiece heat treatment on surface quality of AWJ kerf

Abrasive water jet (AWJ) can be effectively employed on a broad selection of work materials, ranging from polymers to lapideous materials and high grade steels. The AWJ cutting process involves several variables, including hydraulic, abrasive, mixing and cutting parameters. Moreover workpiece properties, mainly modulus and hardness, affect material removal type (cutting and deformation wear mode). This paper concentrates on the influence of the mechanical properties of the workpiece on kerf roughness that is achieving more and more attentions from manufacturers, aiming towards near net shape production. In particular, the same carbon steel (C40 UNI EN 10083-2) was used for all tests; two heat treatments were performed on different specimen sets. AWJ cuts on 'as is' (normalised) and hardened specimens (water-quenched) were realised using different traverse speed. The surface roughnesses of the kerfs at different depths were measured to evaluate process performance. A statistical analysis was carried out to assess the significance of the results. It was found that workpiece hardness affects surface finish in different ways, depending on water pressure, traverse rate and depth of measurement across the kerf. Such results support the theory about two different material removal mechanisms, activated at different levels of jet erosive power

The SenStylus: A Novel Rumble-Feedback Pen Device for CAD Application in Virtual Reality

We have developed a pen device for CAD applications in virtual reality which provides novel features compared to existing systems. The SenStylus consists of a wireless pen designed to be ergonomically handled by the user for spatial interaction using a six degree of freedom optical tracking. In addition to the classic digital button(s) input, it provides analog multi-axial control, and a dual-rumble feedback output. We have integrated the device into an existing virtual reality CAD environment and extended the application functionalities with new devicespecific features. The SenStylus vibration feedback improves perception in the virtual world by controlling frequency, amplitude, and duration of the feedback, simulating a variety of responses during collisions and selection tasks. This capability enforces the visual depth sensitivity, which is critical when wo rking with complex CAD models. The multi-axial analog input provides a natural interaction paradigm to the user, thus simulating pen pressure and angle as in real world sketching and in real clay modeling. Dynamic tool-tip dimensioning and shaping are implemented as extra features. We present some applications to prove the added value of the SenStylus. The evaluation of the device received positive feedback by designers and engineers alike. The new features offered by this device can easily be extended to other VR applications using the API provided

The revival of an \u80\u9cold\u80\u9d marker: CD4/CD8 ratio

The effectiveness of modern antiretroviral therapies transformed HIV infection into a chronic disease characterized by a persistent condition of inflammation and immune activation. For this reason, even though AIDS-related mortality has been reduced with an increased life expectancy, patients living with HIV infection are more likely to develop non-AIDS events despite the achievement of complete suppression of HIV replication. Hence, the scientific community feels the need to find new biomarkers, which would be suitable in clinical practice for identifying patients who require close monitoring because of an increased risk of developing comorbidities. A renewed interest has emerged about the usefulness of the CD4/CD8 ratio as a marker of immune activation and immune senescence. Recently, many studies have underlined that the CD4/CD8 ratio might represent a good predictor of AIDS and non-AIDS events. Herein, the potential role of the CD4/CD8 ratio for monitoring of HIV patients in different clinical settings is reviewed. (AIDS Rev. 2017;19:81-8)