Stair-climbing wheelchair.q05: from the concept to the prototype

In this paper, an electric stair-climbing wheelchair, named wheelchair.q05, able to move on flat ground and to climb stairs, is presented. The proposed solution has been developed through a series of studies and designs, all based on a smart hybrid triple leg-wheel locomotion unit. The stability of the device is guaranteed by a rear support of a pair of pivoting wheels during motion on flat ground, and by the support of an idle track, when climbing on or going down stairs. By means of mechanisms and actuators, it is possible to change the configuration of the wheelchair, from the flat ground motion to the stair climbing configuration

COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy

The outbreak and diffusion of SARS-CoV-2, responsible for the coronavirus disease (COVID-19), has caused an emergency in the health system worldwide. After a first development in Wuhan, China, the virus spread in other countries, with Italy registering the second highest number of cases in Europe on the 7th of April 2020 (135,586 in total). The World Health Organization declared the pandemic diffusion of COVID-19, and restrictive measures to limit contagion have been taken in several countries. The virus has a predominantly respiratory transmission through aerosol and droplets. The importance of infection control is therefore crucial in limiting the effects of virus diffusion. We aim to discuss the risks related to dental practice and current recommendations for dental practitioners. A literature search was performed to retrieve articles on the management of COVID-19 diffusion in dental practice. The documented clinical experience, the measures of professional prevention, and the actual Italian situation were reported and described. Four articles were retrieved from the literature search. Among the eligible articles, 3 reported measures to contrast COVID-19 diffusion. The infection management protocols suggested were reviewed. Finally, recommendations based on the Italian experience in terms of patient triage, patients' entrance into the practice, dental treatment, and after-treatment management are reported and discussed. COVID-19 is a major emergency worldwide, which should not be underestimated. Due to the rapidly evolving situation, further assessment of the implications of COVID-19 outbreak in dental practice is needed

An innovative technique for the investigation of the 4-fold forbidden beta-decay of 50^{50}V

For the first time a Vanadium-based crystal was operated as cryogenic particle detector. The scintillating low temperature calorimetric technique was used for the characterization of a 22 g YVO$_4$ crystal aiming at the investigation of the 4-fold forbidden non-unique $\beta^-$ decay of $^{50}$V. The excellent bolometric performance of the compound together with high light output of the crystal makes it an outstanding technique for the study of such elusive rate process. The internal radioactive contaminations of the crystal are also investigated showing that an improvement on the current status of material selection and purification are needed, $^{235/238}$U and $^{232}$Th are measured at the level of 28 mBq/kg, 1.3 Bq/kg and 28 mBq/kg, respectively. In this work, we also discuss a future upgrade of the experimental set-up which may pave the road for the detection of the rare $^{50}$V $\beta^-$ decay

Hemostatic Agents for the Management of Bleeding Risk Associated with Oral Anticoagulant Therapy Following Tooth Extraction: A Systematic Review

The occurrence of bleeding following dental extraction is a relatively common complication. A history of therapy with oral anticoagulants represents a major favoring factor, both in patients treated with vitamin K-antagonists (especially warfarin) and with direct oral anticoagulants (DOACs). Several local hemostatic measures can be applied to limit the bleeding risk in these patients. The aim of this systematic review is to evaluate what measures can be adopted to limit the bleeding risk following dental extractions in patients treated with oral anticoagulants. A literature search was performed, and 116 articles were retrieved. Titles and abstract analyses excluded 91 articles, and three more articles were excluded following full-text analysis. The systematic review was performed on 22 articles. Among the included articles, 20 studies reported on patients treated with warfarin, and two studies on patients treated with DOACs. The agents employed included local intra-alveolar agents, tranexamic acid, and PRF. The included studies were all at moderate/high risk of bias. Moreover, limited evidence is available on hemostasis in patients treated with DOACs. The available evidence hinders stating the superiority of one agent over the others. Further research is advised to increase the level of evidence of the application of hemostatic agents in patients treated with oral anticoagulants

Relativistic electrons from sparks in the laboratory

Discharge experiments were carried out at the Eindhoven University of Technology in 2013. The experimental setup was designed to search for electrons produced in meter-scale sparks using a 1 MV Marx generator. Negative voltage was applied to the high voltage (HV) electrode. Five thin (1 mm) plastic detectors (5 $\rm cm^2$ each) were distributed in various configurations close to the spark gap. Earlier studies have shown (for HV negative) that X-rays are produced when a cloud of streamers is developed 30-60 cm from the negative electrode. This indicates that the electrons producing the X-rays are also accelerated at this location, that could be in the strong electric field from counterstreamers of opposite polarity. Comparing our measurements with modeling results, we find that $\sim$300 keV electrons produced about 30-60 cm from the negative electrode are the most likely source of our measurements. A statistical analysis of expected detection of photon bursts by these fiber detectors indicates that only 20%-45% of the detected bursts could be from soft ($\sim$10 keV) photons, which further supports that the majority of detected bursts are produced by relativistic electrons

A new investigation of half-lives for the decay modes of 50^{50}V

A new search for the decay modes of the 4-fold forbidden non-unique decay of $^{50}$V has been performed at the Gran Sasso Underground Laboratory (LNGS). In total an exposure of 197 kg $\times$ d has been accumulated. The half-life for the electron capture into the first excited state of $^{50}$Ti has been measured with the highest precision to date as $2.67_{-0.18}^{+0.16} \times 10^{17}$ yr (68% C.I.) in which systematics uncertainties dominate. The search for the $\beta$-decay into the first excited state of $^{50}$Cr resulted in a lower limit of ${1.9} \times 10^{19}$ yr (90% C.I.), which is an improvement of almost one order of magnitude compared to existing results. The sensitivity of the new measurement is now in the region of theoretical predictions

Sustainable Production of Stiff and Crystalline Bacterial Cellulose from Orange Peel Extract

In this work, a potentially economic and environmentally friendly method for the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus from a biomass containing orange peel extract was evaluated. Orange peel extract was used as a culture medium without any hydrolysis treatment, thus speeding up the synthesis procedure. The efficacy of orange peel as a carbon source was compared with that of sucrose. The orange peel extract formed thicker cellulose gels than those formed using sucrose. X-ray diffraction (XRD) revealed both a high crystallinity index and crystallite size of BC nanofibers in samples obtained from orange peel (BC_Orange). Field emission scanning electron microscopy (FE-SEM) revealed a highly densely packed nanofibrous structure (50 nm in diameter). BC_Orange presented a two-fold increase in water holding capacity (WHC), and dynamic mechanical analysis (DMA) showed a 44% increase in storage modulus compared to sucrose derived BC. These results showed that the naturally available carbon sources derived from orange peel extract can be effectively used for BC production. The orange-based culture medium can be considered a profitable alternative to the generation of high-value products in a virtuous circular economy model

Phylogeographyc inferences from the mtDNA variation of the three-toed skink, Chalcides chalcides (Reptilia: Scincidae)

Genetic diversity was analyzed in Chalcides chalcides populations from peninsular Italy, Sardinia, Sicily and Tunisia by sequencing 400 bp at the 50 end of the mitochondrial gene encoding cytochrome b (cyt b) and by restriction fragment length polymorphism (RFLP) analysis of two mitochondrial DNA segments (ND-1/2 and ND-3/4). The results of the phylogenetic analysis highlighted the presence of three main clades corresponding with three of the four main geographical areas (Tunisia, Sicily and the Italian peninsula), while Sardinia proved to be closely related to Tunisian haplotypes suggesting a colonization of this island from North Africa by human agency in historical times. On the contrary, the splitting times estimated on the basis of cyt b sequence data seem to indicate a more ancient colonization of Sicily and the Italian Peninsula, as a consequence of tectonic and climatic events that affected the Mediterranean Basin during the Pleistocene. Finally, the analysis of the genetic variability of C. chalcides populations showed a remarkable genetic homogeneity in Italian populations when compared to the Tunisian ones. This condition could be explained by a rapid post-glacial expansion from refugial populations that implied serial bottlenecking with progressive loss of haplotypes, resulting in a low genetic diversity in the populations inhabiting the more recently colonized areas