Proximal direct composite restorations and chairside CAD/CAM inlays: Marginal adaptation of a two-step self-etch adhesive with and without selective enamel conditioning

The aim of this study was to evaluate the marginal adaptation of CEREC ceramic inlays, CEREC composite inlays and direct composite restorations in unbeveled proximal slot cavities under artificial aging conditions. Two groups of each restoration type were prepared (n = 6), one group with a self-etch adhesive, the other group with H3PO4 enamel etching before the self-etch adhesive application. Replicas were generated before and after long-term thermo-mechanical loading under dentinal fluid simulation and margins were evaluated at ×200 magnification in the scanning electron miscroscope (SEM). Statistically, significant differences were found before and after loading with respect to the percentages of "continuous margins”, the direct composite filling with H3PO4 enamel etching giving the lowest percentages of "continuous margins” after loading (p < 0.05). The highest percentage of "continuous margin” was attained by composite inlays without H3PO4 enamel etching. However, these results were not significantly different from ceramic inlays after stressing. Polymerization shrinkage is still one critical property of composite restorative materials. The marginal adaptation of indirect adhesive proximal slot restorations without enamel bevels both fabricated out of composite and ceramic is better than that of directly placed composite restoration

Exploring the hidden potential of sugar beet industry brownfields (case study of the Czech Republic).

The paper focuses on spatial analyses of sugar beet industry brownfields in the Czech Republic. In the first part of the paper history of sugar beet industry on the area of the Czech Republic is briefly presented, then links between location of these sites and its transport potential are discussed. Benefits of brownfields regeneration for regional development are also evaluated. In the empirical part of the paper 49 brownfield sites within the Czech Republic, where the sugar beet industry was abandoned during the transition period after 1989, are evaluated and classified based on field research and aerial picture analyses. Three examples of reuse of former sugar beet factories are finally presented. It was found that development potential of studied sites is highly depended on their geographical location and some inspiration might be derived from presented examples. More targeted supportive policy in the Czech Republic to support regeneration of brownfields is needed. In the concluding part of the paper further development possibilities of sugar beet industry brownfields and their railway connection are considered

Light curing time reduction: in vitro evaluation of new intensive light-emitting diode curing units

The aim of the present in vitro study was to establish the minimum necessary curing time to bond stainless steel brackets (Mini Diamond Twin™) using new, intensive, light-emitting diode (LED) curing units. Seventy-five bovine primary incisors were divided into five equal groups. A standard light curing adhesive (Transbond™ XT) was used to bond the stainless steel brackets using different lamps and curing times. Two groups were bonded using an intensive LED curing lamp (Ortholux™ LED) for 5 and 10 seconds. Two more groups were bonded using another intensive LED curing device (Ultra-Lume™ LED 5) also for 5 and 10 seconds. Finally, a high-output halogen lamp (Optilux™ 501) was used for 40 seconds to bond the final group, which served as a positive control. All teeth were fixed in hard acrylic and stored for 24 hours in water at 37°C. Shear bond strength (SBS) was measured using an Instron testing machine. Weibull distribution and analysis of variance were used to test for significant differences. The SBS values obtained were significantly different between groups (P < 0.001). When used for 10 seconds, the intensive LED curing units achieved sufficient SBS, comparable with the control. In contrast, 5 seconds resulted in significantly lower SBS. The adhesive remnant index (ARI) was not significantly affected. A curing time of 10 seconds was found to be sufficient to bond metallic brackets to incisors using intensive LED curing units. These new, comparatively inexpensive, curing lamps seem to be an advantageous alternative to conventional halogen lamps for bonding orthodontic bracket

Structure and dynamics of deep-seated slope failures in the Magura Flysch Nappe, outer Western Carpathians (Czech Republic)

International audienceDeep-seated mass movements currently comprise one of the main morphogenetic processes in the Flysch Belt of the Western Carpathians of Central Europe. These mass movements result in a large spectrum of slope failures, depending on the type of movement and the nature of the bedrock. This paper presents the results of a detailed survey and reconstruction of three distinct deep-seated slope failures in the Raca Unit of the Magura Nappe, Flysch Belt of the Western Carpathians in the Czech Republic. An interdisciplinary approach has enabled a global view of the dynamics and development of these deep-seated slope failures. The three cases considered here have revealed a complex, poly-phase development of slope failure. They are deep-seated ones with depths to the failure surface ranging from 50 to 110m. They differ in mechanism of movement, failure structure, current activity, and total displacement. The main factors influencing their development have been flysch-bedrock structure, lithology, faulting by bedrock separation (which enabled further weakening through deep weathering), geomorphic setting, swelling of smectite-rich clays, and finally heavy rainfall. All of the slope failures considered here seem to have originated during humid phases of the Holocene or during the Late Glacial

Caries diagnosis using light fluorescence devices: VistaProof and DIAGNOdent

The modern concept of minimally invasive dentistry encompasses early detection of incipient carious lesions and their treatment. Due to the low sensitivity of visual inspection and radiography in the detection of occlusal hidden carious lesions under a macroscopically sound surface, several devices have been developed to increase detection accuracy. DIAGNOdent is one of the tools used for that purpose and VistaProof is a new device recently introduced into the market. They both use light fluorescence to detect incipient carious lesions. DIAGNOdent is based on the fact that carious lesions show higher level of fluorescence than sound tissues when excited by light at specific wavelength. Vistaproof is based on the same principle, but it uses a different wavelength of excitation than DIAGNOdent and a video camera for the detection of fluorescence. The aim of this article was to compare these two devices and present their clinical use

A new aerosol wet removal scheme for the Lagrangian particle model FLEXPART v10

A new, more physically based wet removal scheme for aerosols has been implemented in the Lagrangian particle dispersion model FLEXPART. It uses three-dimensional cloud water fields from the European Centre for MediumRange Weather Forecasts (ECMWF) to determine cloud extent and distinguishes between in-cloud and below-cloud scavenging. The new in-cloud nucleation scavenging depends on cloud water phase (liquid, ice or mixed-phase), based on the aerosol's prescribed efficiency to serve as ice crystal nuclei and liquid water nuclei, respectively. The impaction scavenging scheme now parameterizes below-cloud removal as a function of aerosol particle size and precipitation type (snow or rain) and intensity. Sensitivity tests with the new scavenging scheme and comparisons with observational data were conducted for three distinct types of primary aerosols, which pose different challenges for modeling wet scavenging due to their differences in solubility, volatility and size distribution: (1) Cs-137 released during the Fukushima nuclear accident attached mainly to highly soluble sulphate aerosol particles, (2) black carbon (BC) aerosol particles, and (3) mineral dust. Calculated e-folding lifetimes of accumulation mode aerosols for these three aerosol types were 11.7, 16.0, and 31.6 days respectively, when well mixed in the atmosphere. These are longer lifetimes than those obtained by the previous removal schem, and, for mineral dust in particular, primarily result from very slow in-cloud removal, which globally is the primary removal mechanism for these accumulation mode particles. Calculated e-folding lifetimes in FLEXPART also have a strong size dependence, with the longest lifetimes found for the accumulation-mode aerosols. For example, for dust particles emitted at the surface the lifetimes were 13.8 days for particles with 1 aem diameter and a few hours for 10 aem particles. A strong size dependence in below-cloud scavenging, combined with increased dry removal, is the primary reason for the shorter lifetimes of the larger particles. The most frequent removal is in-cloud scavenging (85% of all scavenging events) but it occurs primarily in the free troposphere, while below-cloud removal is more frequent below 1000m (52% of all events) and can be important for the initial fate of species emitted at the surface, such as those examined here. For assumed realistic in-cloud removal efficiencies, both BC and sulphate have a slight overestimation of observed atmospheric concentrations (a factor of 1.6 and 1.2 respectively). However, this overestimation is largest close to the sources and thus appears more related to overestimated emissions rather than underestimated removal. The new aerosol wet removal scheme of FLEXPART incorporates more realistic information about clouds and aerosol properties and it compares better with both observed lifetimes and concentration than the old scheme.Peer reviewe

Endothelial C-type natriuretic peptide maintains vascular homeostasis

PMCID: PMC4151218Wellcome Trust (084449/Z/07/Z and 078496/Z/05/Z

Regulation of acetylcholinesterase activity by nitric oxide in rat neuromuscular junction via N-methyl-d-aspartate receptor activation

Acetylcholinesterase (AChE) is an enzyme that hydrolyses the neurotransmitter acetylcholine, thereby limiting spillover and duration of action. This study demonstrates the existence of an endogenous mechanism for the regulation of synaptic AChE activity. At the rat extensor digitorum longus neuromuscular junction, activation of N-methyl-d-aspartate (NMDA) receptors by combined application of glutamate and glycine led to enhancement of nitric oxide (NO) production, resulting in partial AChE inhibition. Partial AChE inhibition was measured using increases in miniature endplate current amplitude. AChE inhibition by paraoxon, inactivation of NO synthase by Nω-nitro-l-arginine methyl ester, and NMDA receptor blockade by dl-2-amino-5-phosphopentanoic acid prevented the increase in miniature endplate current amplitude caused by amino acids. High-frequency (10 Hz) motor nerve stimulation in a glycine-containing bathing solution also resulted in an increase in the amplitude of miniature endplate currents recorded during the interstimulus intervals. Pretreatment with an NO synthase inhibitor and NMDA receptor blockade fully eliminated this effect. This suggests that endogenous glutamate, released into the synaptic cleft as a co-mediator of acetylcholine, is capable of triggering the NMDA receptor/NO synthase-mediated pathway that modulates synaptic AChE activity. Therefore, in addition to well-established modes of synaptic plasticity (e.g. changes in the effectiveness of neurotransmitter release and/or the sensitivity of the postsynaptic membrane), another mechanism exists based on the prompt regulation of AChE activity. NO molecules depress AChE activity in the neuromuscular junction thereby enhancing endplate current amplitude. Endogenous glutamate, released into the synaptic cleft as a co-mediator of acetylcholine, is capable of triggering the NMDA receptor-/NO synthase-mediated pathway that modulates synaptic AChE activity. In addition to well-established modes of synaptic plasticity another mechanism exists based on the prompt regulation of AChE activity. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd

Increase in precipitation scavenging contributes to long-term reductions of light-absorbing aerosol in the Arctic

We investigated long-term changes using a harmonised 22-year data set of aerosol light absorption measurements, in conjunction with air mass history and aerosol source analysis. The measurements were performed at Zeppelin Observatory, Svalbard, from 2002 to 2023. We report a statistically significant decreasing long-term trend for the light absorption coefficient. However, the last 8 years of 2016–2023 showed a slight increase in the magnitude of the light absorption coefficient for the Arctic haze season. In addition, we observed an increasing trend in the single-scattering albedo from 2002 to 2023. Five distinct source regions, representing different transport pathways, were identified. The trends involving air masses from the five regions showed decreasing absorption coefficients, except for the air masses from Eurasia. We show that the changes in the occurrences of each transport pathway cannot explain the reductions in the absorption coefficient observed at the Zeppelin station. An increase in contributions of air masses from more marine regions, with lower absorption coefficients, is compensated for by an influence from high-emission regions. The proportion of air masses en route to Zeppelin, which have been influenced by active fires, has undergone a noticeable increase starting in 2015. However, this increase has not impacted the long-term trends in the concentration of light-absorbing aerosol. Along with aerosol optical properties, we also show an increasing trend in accumulated surface precipitation experienced by air masses en route to the Zeppelin Observatory. We argue that the increase in precipitation, as experienced by air masses arriving at the station, can explain a quarter of the long-term reduction in the light absorption coefficient. We emphasise that meteorological conditions en route to the Zeppelin Observatory are critical for understanding the observed trends.</p

A multi-purpose, multi-rotor drone system for long-range and high-altitude volcanic gas plume measurements

A multi-rotor drone has been adapted for studies of volcanic gas plumes. This adaptation includes improved capacity for high-altitude and long-range, real-time SO2 concentration monitoring, long-range manual control, remotely activated bag sampling and plume speed measurement capability. The drone is capable of acting as a stable platform for various instrument configurations, including multi-component gas analysis system (MultiGAS) instruments for in situ measurements of SO2, H2S, and CO2 concentrations in the gas plume and portable differential optical absorption spectrometer (MobileDOAS) instruments for spectroscopic measurement of total SO2 emission rate, remotely controlled gas sampling in bags and sampling with gas denuders for posterior analysis on the ground of isotopic composition and halogens. The platform we present was field-tested during three campaigns in Papua New Guinea: in 2016 at Tavurvur, Bagana and Ulawun volcanoes, in 2018 at Tavurvur and Langila volcanoes and in 2019 at Tavurvur and Manam volcanoes, as well as in Mt. Etna in Italy in 2017. This paper describes the drone platform and the multiple payloads, the various measurement strategies and an algorithm to correct for different response times of MultiGAS sensors. Specifically, we emphasize the need for an adaptive flight path, together with live data transmission of a plume tracer (such as SO2 concentration) to the ground station, to ensure optimal plume interception when operating beyond the visual line of sight. We present results from a comprehensive plume characterization obtained during a field deployment at Manam volcano in May 2019. The Papua New Guinea region, and particularly Manam volcano, has not been extensively studied for volcanic gases due to its remote location, inaccessible summit region and high level of volcanic activity. We demonstrate that the combination of a multi-rotor drone with modular payloads is a versatile solution to obtain the flux and composition of volcanic plumes, even for the case of a highly active volcano with a high-altitude plume such as Manam. Drone-based measurements offer a valuable solution to volcano research and monitoring applications and provide an alternativespan idCombining double low line"page4256"/&gt; and complementary method to ground-based and direct sampling of volcanic gases