Technologies on Behalf of the Dentistry Dissemination in Pandemic Times: An Interinstitutional Experience

The COVID-19 pandemic persists despite the ongoing mass immunization campaign, and there is a long journey ahead until effective control of the situation. In Brazil, telemedicine has grown widely. After the initial adaptation process during the first pandemic year, remote teaching and teleconsultation/ telemonitoring have consolidated such technology. By definition, telemedicine means the use of information technology to improve health care by approximating professionals and patients in distant locations. However, despite the acceptance in several health areas, dentists have rejected this new approach, claiming that telemedicine lacks the power to attract patients’ attention. To refute wrongly conceived theories and demonstrate the effectiveness of these resources, we described our experiences concerning dental and multidisciplinary residency education in two states (Sergipe and Paraíba) in the northeast region of Brazil, one of the most affected by the pandemic

Spatial lipidomics reveals sphingolipid metabolism as anti-fibrotic target in the liver

\ua9 2025 The Authors. Background and aims: Steatotic liver disease (SLD), which encompasses various causes of fat accumulation in the liver, is a major cause of liver fibrosis. Understanding the specific mechanisms of lipotoxicity, dysregulated lipid metabolism, and the role of different hepatic cell types involved in fibrogenesis is crucial for therapy development. Methods: We analysed liver tissue from SLD patients and 3 mouse models. We combined bulk/spatial lipidomics, transcriptomics, imaging mass cytometry (IMC) and analysis of published spatial and single-cell RNA sequencing (scRNA-seq) data to explore the metabolic microenvironment in fibrosis. Pharmacological inhibition of sphingolipid metabolism with myriocin, fumonisin B1, miglustat and D-PDMP was carried out in hepatic stellate cells (HSCs) and human precision cut liver slices (hPCLSs). Results: Bulk lipidomics revealed increased glycosphingolipids, ether lipids and saturated phosphatidylcholines in fibrotic samples. Spatial lipidomics detected >40 lipid species enriched within fibrotic regions, notably sphingomyelin (SM) 34:1. Using bulk transcriptomics (mouse) and analysis of published spatial transcriptomics data (human) we found that sphingolipid metabolism was also dysregulated in fibrosis at transcriptome level, with increased gene expression for ceramide and glycosphingolipid synthesis. Analysis of human scRNA-seq data showed that sphingolipid-related genes were widely expressed in non-parenchymal cells. By integrating spatial lipidomics with IMC of hepatic cell markers, we found excellent spatial correlation between sphingolipids, such as SM(34:1), and myofibroblasts. Inhibiting sphingolipid metabolism resulted in anti-fibrotic effects in HSCs and hPCLSs. Conclusions: Our spatial multi-omics approach suggests cell type-specific mechanisms of fibrogenesis involving sphingolipid metabolism. Importantly, sphingolipid metabolic pathways are modifiable targets, which may have potential as an anti-fibrotic therapeutic strategy

Paper 2: The Road Surface and Safety of Vehicles

The control of a vehicle depends ultimately on the friction available between its tyres and the road surfaces to give adequate skidding resistance when wet under the many varied conditions of speed and road layout which are encountered in the course of normal driving. Methods of measuring the skidding resistance of road surfaces are described, with particular emphasis on the interpretation of results in relation to accident risk and on the minimum requirements for safety under different road conditions. The features of road surface texture which give these requirements are outlined and results of field surveys show the extent to which the requirements are met at the present time. The influence of tyre tread characteristics on the frictional properties of road surfaces is also discussed. </jats:p

Friction between Conical and Spherical Shaped Sliders and Wet Rubber

Abstract Investigations have shown that a high skidding resistance on wet roads is associated with the presence of sharp edges in the road surface: on these sharp edges high pressures are set up which assist in breaking through the lubricating water film between tire and road. This paper gives some details of laboratory tests now being made to investigate further the dependence of skidding resistance on such localized pressures. Pressure distributions beneath rigid spheres and cones pressed into rubber have been calculated, on the basis of the elastic theory, from measurements of their penetration into tire-tread rubber under load. The experimental evidence confirms that under the conditions of test employed the rubber is behaving as an elastic material. The effect of the pressures on friction under wet conditions has been investigated by sliding different shapes over wet rubber, using a laboratory friction machine designed to simulate conditions between tire and road when skidding takes place. These tests indicate that the coefficient of friction recorded under wet conditions is closely related to the pressure over the contact area between slider and rubber, and that, to ensure a satisfactory skidding resistance in wet weather, the shape of individual projections in the road must be such that average pressures of the order of 1000 lb in−2 are set up on them. Ideally, what is required is that the individual projections in the surface of the road should have angles at their tips of 90° or less : the necessary pressures are unlikely to be obtained with rounded or polished projections, whatever their size or the load applied to them.</jats:p

Road Surface Characteristics and Skidding Resistance

Abstract When roads are wet their skidding resistance is reduced by the lubricating action of the film of water on the road. Under some circumstances this reduction may be substantial and the extent of it is largely dependent on the characteristics of the road surface. The first requirement for a good skidding resistance on wet roads is to facilitate break through of the water film in order to establish areas of dry contact between the road and the tire. Drainage channels, provided by the large scale texture of the road or by a pattern on the tire, assist in getting rid of the main bulk of water and are of increasing importance the higher the speed. The penetration of the remaining water film can be achieved only if there are sufficient fine scale sharp edges in the road on which high pressures (about 1000 lb/in2) are built up. The existence of such fine scale sharpness gives the surfaces a harsh feel. When vehicles are travelling at speeds of about 30 mph the fine scale texture of the road is the dominant factor determining skidding resistance. However, as they travel faster, it becomes increasingly difficult to penetrate the water film in the time available, however harsh the surface. At high speeds the requirements for a good skidding resistance are therefore different. The resistance to skidding arises to a larger extent from energy losses in the rubber of the tire as the surface of the tread is deformed by projections in the road surface and, although the physical properties of the tread rubber are important in this respect, it is essential to have sufficiently large and angular projections in the road surface to deform the tread, even though a water film may still be present on the surface. At higher speeds the coarseness of texture becomes as important as its harshness.</jats:p