713 research outputs found
Further insights on predictors of environmental tobacco smoke exposure during the pediatric age
Background: The smoking ban in public places has reduced Environmental Tobacco Smoke (ETS) exposure for non-smokers, but despite this, domestic environments still remain places at high risk of exposure, and, today, about 40% of children worldwide are exposed to ETS at home. The aims of the study are to investigate the contribution of several factors on ETS exposure among a group of Italian children and to evaluate the changes in smoking precautions adopted at home when the smoker is the mother, the father, or both parents, respectively. Methods: A cross-sectional study was performed on a sample of 519 Italian schoolchildren. Information was collected via a questionnaire. Results: 41.4% of the participants lived with at least one smoker. Almost half of the children exposed to ETS lived with one or more smokers who do not observe any home smoking ban. Lower maternal or paternal educational levels significantly increase the risk of ETS exposure at home and the “worst case” is represented by both parents who smoke. Conclusions: More effective preventive interventions are needed to protect children from ETS exposure. Some interventions should be specifically dedicated to smokers with a low educational level and to mothers that smoke
Heavy electrons: Electron droplets generated by photogalvanic and pyroelectric effects
Electron clusters, X-rays and nanosecond radio-frequency pulses are produced
by 100 mW continuous-wave laser illuminating ferroelectric crystal of LiNbO_3.
A long-living stable electron droplet with the size of about 100 mcm has freely
moved with the velocity 0.5 cm/s in the air near the surface of the crystal
experiencing the Earth gravitational field. The microscopic model of cluster
stability, which is based on submicroscopic mechanics developed in the real
physical space, is suggested. The role of a restraining force plays the inerton
field, a substructure of the particles' matter waves, which a solitary one can
elastically withstand the Coulomb repulsion of electrons. It is shown that
electrons in the droplet are heavy electrons whose mass at least 1 million of
times exceeds the rest mass of free electron. Application for X-ray imaging and
lithography is discussed.Comment: 15 p., 3 fig
Isotopic Grand Unification with the Inclusion of Gravity (revised version)
We introduce a dual lifting of unified gauge theories, the first
characterized by the isotopies, which are axiom- preserving maps into broader
structures with positive-definite generalized units used for the representation
of matter under the isotopies of the Poincare' symmetry, and the second
characterized by the isodualities, which are anti-isomorphic maps with
negative-definite generalized units used for the representation of antimatter
under the isodualities of the Poincare' symmetry. We then submit, apparently
for the first time, a novel grand unification with the inclusion of gravity for
matter embedded in the generalized positive-definite units of unified gauge
theories while gravity for antimatter is embedded in the isodual isounit. We
then show that the proposed grand unification provides realistic possibilities
for a resolution of the axiomatic incompatibilities between gravitation and
electroweak interactions due to curvature, antimatter and the fundamental
space-time symmetries.Comment: 20 pages, Latex, revised in various details and with added reference
Gait analysis advancements: rehabilitation value and new perspectives from forensic application
The clinical and rehabilitation value of gait analysis is remarkable and indisputable and poised to grow as technological advancements unfold. This article aims to shed light on the advances in how gait is assessed, enabling those who have suffered an injury impairing their motor skills to be diagnosed more accurately and efficiently as well as to compare the hallmarks of rehabilitative and forensic gait analysis. The authors have conducted an analysis of relevant papers (published between 1967 and 2020) from a medicolegal perspective, cited in PubMed, MEDLINE, Cochrane Library, EMBASE, and available recommendations for the legal application of such techniques. Moreover, considering the use of gait analysis as a forensic tool, this study broadens the scope of research by including search engines, legal databases, and court filings (DeJure, Lexis Nexis, Justia) between 2000 and 2022. The instrumental assessment of movement (Gait Analysis) has come to constitute an essential analytical tool for the biomedical sector to objectively and accurately assess human movement and posture. The article is also aimed at elaborating differences and similarities between clinical and forensic gait analysis. When it comes to the forensic applicability of gait analysis and its evidentiary value, however, there is a pressing need for a review of its scientific basis. Therefore, it is necessary to conduct a thorough evaluation of its use in legal practice, as stressed in scientific literature and surveys. It is of utmost importance to highlight the procedural and assessment standards currently applied to forensic gait analysis, to evaluate its strengths and weaknesses, and to achieve standardized guidelines based on broad scientific consensus
Invariant variational principle for Hamiltonian mechanics
It is shown that the action for Hamiltonian equations of motion can be
brought into invariant symplectic form. In other words, it can be formulated
directly in terms of the symplectic structure without any need to
choose some 1-form , such that , which is not unique
and does not even generally exist in a global sense.Comment: final version; to appear in J.Phys.A; 17 pages, 2 figure
A probabilistic approach to the evaluation of seismic resilience in road asset management
Road networks are classified as critical infrastructure systems. Their loss of functionality not only hinders residential and commercial activities, but also compromises evacuation and rescue after disasters. Dealing with risks to key strategic objectives is not new to asset management, and risk management is considered one of the core elements of asset management. Risk analysis has recently focused on understanding and designing strategies for resilience, especially in the case of seismic events that present a significant hazard to highway transportation networks. Following a review of risk and resilience concepts and metrics, an innovative methodology to stochastically assess the economic resources needed to restore damaged infrastructures, one that is a relevant and complementary element within a wider resilience-based framework, is proposed. The original methodology is based on collecting and analyzing ex post reconstruction and hazard data and was calibrated on data measured during the earthquake that struck central Italy in 2016 and collected in the following recovery phase. Although further improvements are needed, the proposed approach can be used effectively by road managers to provide useful information in developing seismic retrofitting plans
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A Comparative Study on Graphene Oxide and Carbon Nanotube Reinforcement of PMMA-Siloxane-Silica Anticorrosive Coatings.
Carbon nanotubes (CNTs) and graphene oxide (GO) have been used to reinforce PMMA-siloxane-silica nanocomposites considered to be promising candidates for environmentally compliant anticorrosive coatings. The organic-inorganic hybrids were prepared by benzoyl peroxide (BPO)-induced polymerization of methyl methacrylate (MMA) covalently bonded through 3-(trimethoxysilyl)propyl methacrylate (MPTS) to silica domains formed by hydrolytic condensation of tetraethoxysilane (TEOS). Single-walled carbon nanotubes and graphene oxide nanosheets were dispersed by surfactant addition and in a water/ethanol solution, respectively. These were added to PMMA-siloxane-silica hybrids at a carbon (CNT or GO) to silicon (TEOS and MPTS) molar ratio of 0.05% in two different matrices, both prepared at BPO/MMA molar ratios of 0.01 and 0.05. Atomic force microscopy and scanning electron microscopy showed very smooth, homogeneous, and defect-free surfaces of approximately 3-7 ÎĽm thick coatings deposited onto A1020 carbon steel by dip coating. Mechanical testing and thermogravimetric analysis confirmed that both additives CNT and GO improved the scratch resistance, adhesion, wear resistance, and thermal stability of PMMA-siloxane-silica coatings. Results of electrochemical impedance spectroscopy in 3.5% NaCl solution, discussed in terms of equivalent circuits, showed that the reinforced hybrid coatings act as a very efficient anticorrosive barrier with an impedance modulus up to 1 GΩ cm(2), approximately 5 orders of magnitude higher than that of bare carbon steel. In the case of GO addition, the high corrosion resistance was maintained for more than 6 months in saline medium. These results suggest that both carbon nanostructures can be used as structural reinforcement agents, improving the thermal and mechanical resistance of high performance anticorrosive PMMA-siloxane-silica coatings and thus extending their application range to abrasive environments.This work was supported by Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES), and SĂŁo Paulo Research Foundation (FAPESP)This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acsami.6b0478
Laser and thermal therapy in athletes’ tennis elbow: an observational study
BACKGROUND: Lateral epicondylitis (LE), is a widespread painful situation in the upper extremity that usually occurs due to overuse of the wrist extensor muscles. The aim of our study was to investigate the analgesic and functional effects of laser therapy in association with thermal therapy in sports patients suffering from lateral epicondylitis. METHODS: We retrospectively analyzed amateur tennis patients who played sports at least 3 times a week, with medical and ultrasound diagnosis of subacute lateral epicondylitis. All patients underwent 6 sessions of Laser therapy with qmd® Helios laser. A group of patients instead (23, Thermal-Laser Group, TLG), underwent a session of Thermal therapy (qmd® Helios cryo-thermal) before the Laser therapy. The Laser Group (21, LG) on the other hand only performed laser therapy. Patients included in the study were evaluated at baseline (T0), at the end of treatment (T1) and after 15 days from the end of treatment (T2 through Visual Analogue Scale-VAS, muscle strength (Dynamometer) and function (Disabilities of the Arm, Shoulder and Hand-DASH questionnaire). RESULTS: Fifty-two patients (23 M, 21 F) were enrolled (21 LG; 23 TLG). All evaluations performed show significant improvement over time in both groups. The TLG shows at T1 a greater increase in force compared to the LG. CONCLUSIONS: Laser therapy has certainly been an effective intervention in the management of epicondyle pain for some time. More studies with a higher number of patients and longer follow-up are needed in order to better characterize the benefits of this combination therapy
Regenerative potential of DPSCs and revascularization. direct, paracrine or autocrine effect?
A new source of mesenchymal stem cells has recently been discovered, the so-called dental pulp derived stem cells (DPSCs) which therefore could represent potentially tools for regenerative medicine. DPSC originate from the neural crest and are physiologically involved in dentin homeostasis; moreover, they contribute to bone remodeling and differentiation into several tissues including cartilage, bone, adipose and nervous tissues. DPSCs have also been shown to influence the angiogenesis process, for example through the release of secretory factors or by differentiating into vascular and/or perivascular cells. Angiogenesis, that has a pivotal role in tissue regeneration and repair, is defined as the formation of new vessels from preexisting vessels and is mediated by mutual and reciprocal interactions between endothelial cells and perivascular cells. It is also known that co-cultures of perivascular and endothelial cells (ECs) can form a vascular network in vitro and also in vivo. Since DPSCs seem to have characteristics similar to pericytes, understanding the possible mechanism of interaction between DPSCs and ECs during neo-angiogenesis is dramatically important for the development of advanced clinical application in the field of regeneration. Graphical abstract: [Figure not available: see fulltext.
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