The impact of cigarette/e-cigarette vapour on simulated pulmonary surfactant monolayers under physiologically relevant conditions

Deviation in pulmonary surfactant structure–function activity can impair airway patency and lead to respiratory disorders. This novel study aims to evaluate the influence cigarette/e-cigarette vapour has on model surfactant films located within a simulated pulmonary environment using a lung biosimulator. Chromatographic analysis confirmed that nicotine levels were consistent with the sampling regimen employed. On exposure to smoke vapour, Langmuir isotherms exhibited condensed character and a significant reduction in maximum surface pressure was noted in all cases. Langmuir isocycles, reflective of the human breathing cycle, demonstrated condensed character on smoke vapour delivery. A reduction in themaximumsurface pressure was clear only in the case of cigarette vapour application. The components of cigarette vapour can cause oxidative damage to pulmonary surfactant and impair recycling. Neutral nicotine molecules can weaken the structure of the monolayer and cause destabilisation. A protective effect was evident in the case of repeated surfactant compression – relaxation cycles (i.e. the ability to reduce the surface tension term was impaired less), demonstrating a likely innate biological defensive mechanism of the lung. E-cigarette vapour appeared to have a reduced impact on surfactant performance, which may hold value in harm reduction over the longer term

A comparative study on colour and surface parameters of current esthetic restorative CAD/CAM materials

With the development of newer technologies, computer aided design and computer aided manufacturing help immensely in designing, planning and creating a dental prosthesis with the precise 3-D printing technology. Recently, patients are at increasing demand for everlasting colour stability of restorations in such a way that it improves the aesthetic appearance of teeth. CAD/CAM systems are developed to assemble all ceramic materials which restores the aesthetic zone, attributing to the aesthetics and its clinical long-term survivability.A well-known fact that the type, thickness, composition, curing protocols, and polishing methods of resin composites influences the colour characteristics of the restorations. 99 all-ceramic samples with both glazed or polished CAD/CAM were taken into study. The samples were assessed for the surface roughness (Ra) and colour change after immersion in hot and coffee drink and then were subjected to thermocycling for about 30 days. Total samples of 99 among which 33 samples were manufactured from   Vita Enamic, Vitablocs Mark II, and Vita Suprinity.  All the disc were milled uniformly to obtain a standard dimension of 10mm ×10 mm±0.2 diameter and the thickness of the block ranges from 2.0±0.2 mm based on the manufacturer’s instructions using a CAD/CAM machine (Amann Girrbach, Germany) and then glazed

A Comparative Study on Colour and Surface Parameters of Current Esthetic Restorative CAD/CAM Materials

With the development of newer technologies, computer aided design and computer aided manufacturing help immensely in designing, planning and creating a dental prosthesis with the precise 3-D printing technology. Recently, patients are at increasing demand for everlasting colour stability of restorations in such a way that it improves the aesthetic appearance of teeth. CAD/CAM systems are developed to assemble all ceramic materials which restores the aesthetic zone, attributing to the aesthetics and its clinical long-term survivability.A well-known fact that the type, thickness, composition, curing protocols, and polishing methods of resin composites influences the colour characteristics of the restorations. 99 all-ceramic samples with both glazed or polished CAD/CAM were taken into study. The samples were assessed for the surface roughness (Ra) and colour change after immersion in hot and coffee drink and then were subjected to thermocycling for about 30 days. Total samples of 99 among which 33 samples were manufactured from   Vita Enamic, Vitablocs Mark II, and Vita Suprinity.  All the disc were milled uniformly to obtain a standard dimension of 10mm ×10 mm±0.2 diameter and the thickness of the block ranges from 2.0±0.2 mm based on the manufacturer's instructions using a CAD/CAM machine (Amann Girrbach, Germany) and then glazed

Volatile organic compounds (VOCs) removal capacity of ZSM-5 zeolite adsorbents for near real-time BTEX detection

International audienceThe environmental impact of air pollution along with the registered detrimental effects on human health due to BTEX exposure have forced most countries to set limit values in public spaces and buildings, requiring the development of in situ devices able to quantify in (near)-real time the pollutants concentration, even at ppb levels. In this work, several ZSM-5 zeolites with 79 < Si / Al < 316 have been synthesized and used as part of a pre-concentration unit connected to a miniaturized GC prototype, needed to drop the detection limit according to current legislation. The most important parameters influencing the multicomponent gas-phase adsorption of BTEX over ZSM-5 zeolites have been found to be the number of available acid sites (Al content), the zeolite pore size and its hydrophobicity. The experimental results demonstrate that a compromise between the hydrophobic character and the number of Al atoms should be found in order to properly design an adsorbent for near-real time BTEX detection