The purpose of this manuscript is to discuss the current available methods to detect early lesions amenable to prevention. The current evidenced-based caries understanding, based on biological ...concepts, involves new approaches in caries detection, assessment, and management that should include non-cavitated lesions. Even though the importance of management of non-cavitated (NC) lesions has been recognized since the early 1900 s, dental caries has been traditionally detected at the cavitation stage, and its management has focused strongly on operative treatment. Methods of detection of early carious lesions have received significant research attention over the last 20 years. The most common method of caries detection is visual-tactile. Other non-invasive techniques for detection of early caries have been developed and investigated such as Quantitative Light-induced Fluorescence (QLF), DIAGNOdent (DD), Fibre-optic Transillumination (FOTI) and Electrical Conductance (EC). Based on previous systematic reviews, the diagnosis of NCCLs might be more accurately achieved in combination of the visual method and the use of other methods such as electrical methods and QLF for monitoring purposes.
This article presents ORB-SLAM3, the first system able to perform visual, visual-inertial and multimap SLAM with monocular, stereo and RGB-D cameras, using pin-hole and fisheye lens models. The first ...main novelty is a tightly integrated visual-inertial SLAM system that fully relies on maximum a posteriori (MAP) estimation, even during IMU initialization, resulting in real-time robust operation in small and large, indoor and outdoor environments, being two to ten times more accurate than previous approaches. The second main novelty is a multiple map system relying on a new place recognition method with improved recall that lets ORB-SLAM3 survive to long periods of poor visual information: when it gets lost, it starts a new map that will be seamlessly merged with previous maps when revisiting them. Compared with visual odometry systems that only use information from the last few seconds, ORB-SLAM3 is the first system able to reuse in all the algorithm stages all previous information from high parallax co-visible keyframes, even if they are widely separated in time or come from previous mapping sessions, boosting accuracy. Our experiments show that, in all sensor configurations, ORB-SLAM3 is as robust as the best systems available in the literature and significantly more accurate. Notably, our stereo-inertial SLAM achieves an average accuracy of 3.5 cm in the EuRoC drone and 9 mm under quick hand-held motions in the room of TUM-VI dataset, representative of AR/VR scenarios. For the benefit of the community we make public the source code.
Magnetic refrigeration (MR) at room temperature is an emerging technology and shows real potential to enter conventional markets. The principle of MR obeys the magnetocaloric effect (MCE), which is ...based on the effect caused by a magnetic field on the materials that bear the property of varying the magnetic entropy, as well as its temperature, when varying the magnetic field. This article revises the MCE, its theory and thermodynamics. It discusses the properties that must be met by the magnetocaloric materials as well as those most suitable for room temperature MR and those displaying a promising future. Finally, a presentation and description of the Carnot, Brayton, Ericsson, AMR and cascading MR cycles is given with a view to establishing selection criteria based on their performances.
We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1–3.1 GHz observations with the Australia Telescope Compact ...Array over 18 consecutive days in April 2017. We detected radio emission from Proxima Centauri for most of the observing sessions, which spanned ~1.6 orbital periods of the planet Proxima b. The radio emission is stronger at the low-frequency band, centered around 1.6 GHz, and is consistent with the expected electron-cyclotron frequency for the known star’s magnetic field intensity of ~600 gauss. The 1.6 GHz light curve shows an emission pattern that is consistent with the orbital period of the planet Proxima b around the star Proxima, with its maxima of emission happening near the quadratures. We also observed two short-duration flares (a few minutes) and a long-duration burst (about three days) whose peaks happened close to the quadratures. We find that the frequency, large degree of circular polarization, change in the sign of circular polarization, and intensity of the observed radio emission are all consistent with expectations from electron cyclotron-maser emission arising from sub-Alfvénic star–planet interaction. We interpret our radio observations as signatures of interaction between the planet Proxima b and its host star Proxima. We advocate for monitoring other dwarf stars with planets to eventually reveal periodic radio emission due to star–planet interaction, thus opening a new avenue for exoplanet hunting and the study of a new field of exoplanet–star plasma interaction.
In this work we briefly describe the most relevant features of WSXM, a freeware scanning probe microscopy software based on MS-Windows. The article is structured in three different sections: The ...introduction is a perspective on the importance of software on scanning probe microscopy. The second section is devoted to describe the general structure of the application; in this section the capabilities of WSXM to read third party files are stressed. Finally, a detailed discussion of some relevant procedures of the software is carried out.
Gully erosion has become a field of growing interest among the research community but there still are numerous knowledge gaps that need to be addressed. The aim of this work is to carry out a ...systematic review on significant trends in gully erosion research included in the Web of Science database in order to evaluate the survey methodologies, evaluate the impact of key factors on the complexity of gully erosion responses and raise public awareness of this urgent environmental issue. Gully erosion represents at present around 10% of soil erosion research, a percentage that is at odds with being the worst form of soil degradation in agricultural areas. Despite the fact that it is an ubiquitous process all around the world, the worst stages of degradation take place where unsustainable human practices operate in erosion-prone conditions such as erodible soils, soft lithologies or geotechnically instable slopes. Anthropic influence is typically the main driver of gully erosion evolution and has acted differently in time and results across the countries depending on the history of land use and management practices. Although gully erosion is known to be largely controlled by deep-profile properties, the study on subsurface processes has frequently remained mostly descriptive and it is losing ground to other more recent techniques aiming to assess morphological changes. We found empirical support for the argument that deeper incision tends to lead to higher degradation rates, which endorses the focus on subsurface dynamics and early control to prevent catastrophic land degradation. Long-standing detailed survey programmes are still scarce in gully erosion studies all of which hampers a reliable evaluation of this highly variable phenomenon. Further coordinated and sustained research efforts are still required to tackle this urgent environmental problem through better understanding (e.g. building longer and consistent data series, combining survey methodologies regarding surface and subsurface factors, providing standardised guidelines for interpretation), more effective control implementation and wider dissemination.
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•Hydrothermal treatment of Coal fly produce cancrinite and analcime zeolite.•Cancrinite zeolite exhibits ferrimagnetic signature.•Adsorption of blue methylene is described by ...Freundlich and Langmuir models.
Coal fly ash (CFA) was obtained from the Sochagota TermoPaipa IV power plant in Boyacá Colombia. CFA was subjected to a hydrothermal activation with NaOH. Morphology, elemental and mineralogical composition and magnetic properties of the obtained products were studied by means of SEM-EDX, XRD and VSM.
Activation with NaOH (4–5 M) between 80 and 150 °C for 24 h produced cancrinite zeolite; activation with NaOH at 2 and 3 M at 95 °C produced analcime zeolite. It was found out, that the synthesized zeolites exhibit a ferrimagnetic behavior due to iron coming from CFA. The magnetic response of the obtained products allows the use of these materials to environmental applications in aqueous medium. Adsorption test for methylene blue was performed for an analcime and cancrinite zeolite, the results show that equilibrium is reached after 60 min. The data of adsorption isotherms for analcime and cancrinite zeolite were fitted to Freundlich and Langmuir model, respectively. The synthesized zeolites from CFA were successfully used to remove methylene blue from aqueous solution.
The antioxidant activities (AA) of
Sechium edule extracts were tested by three established in vitro methods, namely reducing power, β-carotene linoleate model and 1,1- diphenyl-2 picrylhydrazyl ...(DPPH) radical-scavenging. Leaf ethanolic extracts and leaf and seed water extracts showed strong inhibitory activity by β-carotene bleaching (AA values of 90%). Furthermore, these extracts exerted hydrogen-donating ability in the presence of DDPH stable radical (IC
50 2
μg/ml). These extracts also showed strong reducing power by the potassium ferricyanide reduction method. Leaf and seed extracts may be exploited as biopreservatives in food applications as well as for health supplements or functional food, to aleviate oxidative stress.
We explore the unusual electromagnetic response of ultrathin anisotropic σ-near-zero uniaxial metasurfaces, demonstrating extreme topological transitions--from closed elliptical to open ...hyperbolic--for surface plasmon propagation, associated with a dramatic tailoring of the local density of states. The proposed metasurfaces may be implemented using nanostructured graphene monolayers and open unprecedented venues for extreme light confinement and unusual propagation and guidance, combined with large tunability via electric bias.
Modest and even severe vitamin D deficiency is widely prevalent around the world. There is consensus that a good vitamin D status is necessary for bone and general health. Similarly, a better vitamin ...D status is essential for optimal efficacy of antiresorptive treatments. Supplementation of food with vitamin D or using vitamin D supplements is the most widely used strategy to improve the vitamin status. Cholecalciferol (vitamin D
3
) and ergocalciferol (vitamin D
2
) are the most widely used compounds and the relative use of both products depends on historical or practical reasons. Oral intake of calcifediol (25OHD
3
) rather than vitamin D itself should also be considered for oral supplementation. We reviewed all publications dealing with a comparison of oral cholecalciferol with oral calcifediol as to define the relative efficacy of both compounds for improving the vitamin D status. First, oral calcifediol results in a more rapid increase in serum 25OHD compared to oral cholecalciferol. Second, oral calcifediol is more potent than cholecalciferol, so that lower dosages are needed. Based on the results of nine RCTs comparing physiologic doses of oral cholecalciferol with oral calcifediol, calcifediol was 3.2-fold more potent than oral cholecalciferol. Indeed, when using dosages ≤ 25 μg/day, serum 25OHD increased by 1.5 ± 0.9 nmol/l for each 1 μg cholecalciferol, whereas this was 4.8 ± 1.2 nmol/l for oral calcifediol
.
Third, oral calcifediol has a higher rate of intestinal absorption and this may have important advantages in case of decreased intestinal absorption capacity due to a variety of diseases. A potential additional advantage of oral calcifediol is a linear dose-response curve, irrespective of baseline serum 25OHD, whereas the rise in serum 25OHD is lower after oral cholecalciferol, when baseline serum 25OHD is higher. Finally, intermittent intake of calcifediol results in fairly stable serum 25OHD compared with greater fluctuations after intermittent oral cholecalciferol.
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