467 research outputs found

    Understanding taxi travel demand patterns through Floating Car Data

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    This paper analyses the current structure of taxi service use in Rome, processing taxi Floating Car Data (FCD). The methodology used to pass from the original data to data useful for the demand analyses is described. Further, the patterns of within-day and day-to-day service demand are reported, considering the origin, the destination and other characteristics of the trips (e.g. travel time). The analyses reported in the paper can help the definition of space-temporal characteristics of future Shared Autonomous Electrical Vehicles (SAEVs) demand in mobility scenarios

    Common nonlinear features and spin-orbit coupling effects in the Zeeman splitting of novel wurtzite materials

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    The response of semiconductor materials to external magnetic fields is a reliable approach to probe intrinsic electronic and spin-dependent properties. In this study, we investigate the common Zeeman splitting features of novel wurtzite materials, namely, InP, InAs, and GaAs. We present values for the effective g factors of different energy bands and show that spin-orbit coupling effects, responsible for the spin splittings, also have noticeable contributions to the g factors. Within the Landau level picture, we show that the nonlinear Zeeman splitting recently explained in magnetophotoluminescence experiments for InP nanowires by D. Tedeschi et al. [Phys. Rev. B 99, 161204 (2019)] is also present in InAs, GaAs, and even the conventional GaN. Such nonlinear features stem from the peculiar coupling of the A and B valence bands as a consequence of the interplay between the wurtzite crystal symmetry and the breaking of time-reversal symmetry by the external magnetic field. Moreover, we develop an analytical model to describe the experimental nonlinear Zeeman splitting and apply it to InP and GaAs data. Extrapolating our fitted results, we found that the Zeeman splitting of InP reaches a maximum value, which is a prediction that could be probed at higher magnetic fields

    Pediatric patients tolerance: a comparative study about using of Er:YAG laser and self-adhesive flowable composite for treatment of primary decayed teeth

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    Aim. To verify the tolerance of children aged between 3 and 8 years, having class I caries and treated with Er:YAG laser in association with a new self-adhesive flowable resin in comparison with a highspeed diamond bur and a conventional flowable resin treatment. Methods. A group of 80 healthy children (43 males and 37 females) ranging in age from 3 to 8 years, who had been diagnosed with at least one active occlusal non-cavitated superficial carious lesions in first or second deciduous molars, were selected for the present study. They were divided in 4 groups: group A: Class I occlusal cavities prepared using an Er: YAG laser and a self-adhesive flowable resin; Group B: Class I occlusal cavities prepared using an Er: YAG laser and a conventional flowable resin; Group C: Class I occlusal cavities prepared using a high-speed diamond bur and a self-adhesive flowable resin; Group D: Class I occlusal cavities prepared using a high-speed diamond bur and a conventional flowable resin. Before and after the treatments the patient tolerance was tested with the modified Wong-Baker pain level scale. Results. In the first group, the tolerance rate was 95% with 0 score (no hurt) for 19 patients; in Group D, the tolerance rate was 75%. Just one child of group D experienced hurting worst because of non cooperative patient. Conclusion. From these results it emerged that, although the limits of the study, Er:Yag laser in association with self-adhering composite, is very effective in pediatric dentistry and is a good treatment option especially for non cooperative patients

    Risk factors for obstructive sleep apnea syndrome in children: state of the art

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    The obstructive sleep apnea syndrome (OSAS) represents only part of a large group of pathologies of variable entity called respiratory sleep disorders (RSD) which include simple snoring and increased upper airway resistance syndrome (UARS). Although the etiopathogenesis of adult OSAS is well known, many aspects of this syndrome in children are still debated. Its prevalence is about 2% in children from 2 to 8 years of age, mostly related to the size of the upper airways adenoid tissue. Several risk factors linked to the development of OSAS are typical of the pediatric age. The object of this paper is to analyze the state of the art on this specific topic, discussing its implications in terms of diagnosis and management

    Obstructive sleep apnoea in patients treated for head and neck cancer: A systematic review of the literature

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    Background and objectives: Obstructive sleep apnoea (OSA) is clinically defined by signs of daytime sleepiness and objective measures of disordered breathing during sleep. The literature is still controversial on the incidence and aetiology of OSA secondary to head and neck cancer treatment. The aim of this systematic review is to evaluate and discuss the prevalence of OSA in patients treated with surgery and/or chemo/radiotherapy for head and neck cancer. Materials and methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search was performed on May 2020 using the MEDLINE database, Scopus, and Google Scholar. The searches were conducted using combinations of the following terms: head and neck cancer, OSA, radiotherapy, chemotherapy, partial laryngectomy, laryngeal cancer, neoplasm, tumour, carcinoma, and oropharyngeal cancer. Results: Our results suggest that head and neck cancer patients have a higher incidence of OSA (59.78%) compared to the general population; differences may occur based on the type of treatment. Conclusions: Clinicians should recognise the higher prevalence of OSA in patients treated for head and neck cancer and should consider a comprehensive sleep history as part of the evaluation and management of these patients. Further research is needed to evaluate the exact prevalence, aetiology, and correct management of OSA after treatment for head and neck cancer

    CBCT and intra-oral scanner: the advantages of 3D technologies in orthodontic treatment

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    Background: The aim is to demonstrate the validity of the monitoring through intraoral scanner of the dental movements and the real impact, advantages, and convenience, in terms of treatment time and efficiency gain, to frequently monitor a patient with the scanner application. Methods: A movement control of palatally impacted canines was performed, surgically treated with laser opercolectomy. Three-dimensional models of the patient’s dental arch were obtained with intraoral scanner during a monitoring time of 4 months. The STL (Standard Triangle Language) files were superimposed with the 3D models extrapolated from the pre-operative CT (Computerized Tomography). The measurements of eruption, exposed palatal and vestibular areas, and distances between the canines and the incisors were performed, using digital technologies and with a digital caliber. Results: Descriptive and inferential statistical analysis of the data obtained from both conventional and digital monitoring has been realized and performing the T Student Test for paired data. Conclusion: The advantages of digital monitoring are numerous, like the possibility to reduce the error of method caused by manual measurement on plaster casts and the possibility to compare the pattern and amount of eruption of the canine in the same patient overtime

    4,4′-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) Lead Iodide C30H22N2Pb2I6: A Highly Luminescent, Chemically and Thermally Stable One-Dimensional Hybrid Iodoplumbate

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    A new one-dimensional hybrid iodoplumbate, namely, 4,4′-(anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1- pyridinium) lead iodide C30H22N2Pb2I6 (AEPyPbI), is reported here for the first time with its complete characterization. The material exhibits remarkable thermal stability (up to 300 °C), and it is unreactive under ambient conditions toward water and atmospheric oxygen, due to the quaternary nature of the nitrogen atoms present in the organic cation. The cation exhibits strong visible fluorescence under ultraviolet (UV) irradiation, and when its iodide is combined with PbI2, it forms AEPyPb2I6, an efficient light-emitting material, with a photoluminescence emission intensity comparable to that of high-quality InP epilayers. The structure determination was obtained using three-dimensional electron diffraction, and the material was extensively studied by using a wide range of techniques, such as X-ray powder diffraction, diffuse reflectance UV−visible spectroscopy, thermogravimetry-differential thermal analysis, elemental analysis, Raman and infrared spectroscopies, and photoluminescence spectroscopy. The emissive properties of the material were correlated with its electronic structure by using state-of-the-art theoretical calculations. The complex, highly conjugated electronic structure of the cation interacts strongly with that of the Pb−I network, giving rise to the peculiar optoelectronic properties of AEPyPb2I6. The material, considering its relatively easy synthesis and stability, shows promise for lightemitting and photovoltaic devices. The use of highly conjugated quaternary ammonium cations may be useful for the development of new hybrid iodoplumbates and perovskites with optoelectronic properties tailored for specific applications

    Gap Opening in Double-Sided Highly Hydrogenated Free-Standing Graphene

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    Conversion of free-standing graphene into pure graphane-where each C atom is sp3bound to a hydrogen atom-has not been achieved so far, in spite of numerous experimental attempts. Here, we obtain an unprecedented level of hydrogenation (≈90% of sp3bonds) by exposing fully free-standing nanoporous samples-constituted by a single to a few veils of smoothly rippled graphene-to atomic hydrogen in ultrahigh vacuum. Such a controlled hydrogenation of high-quality and high-specific-area samples converts the original conductive graphene into a wide gap semiconductor, with the valence band maximum (VBM) ∼3.5 eV below the Fermi level, as monitored by photoemission spectromicroscopy and confirmed by theoretical predictions. In fact, the calculated band structure unequivocally identifies the achievement of a stable, double-sided fully hydrogenated configuration, with gap opening and no trace of πstates, in excellent agreement with the experimental results

    Association between subclinical atherosclerosis and oral inflammation: a cross-sectional study

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    Background: The aim of this cross-sectional study was to investigate the association between carotid intima-media thickness (c-IMT) values and periodontal and peri-implant diseases in a sample of patients with hypertension. Methods: A total of 151 participants with presence of at least one dental implant in function for >5 years were recruited. Anthropometric measurements, 24-h ambulatory blood pressure monitoring, ultrasound assessment of carotid arteries (c-IMT and presence of plaque) were recorded and venous blood samples obtained. An oral examination was performed by calibrated examiners to ascertain prevalence and severity of periodontal and peri-implant diseases. Binomial logistic regression was performed to investigate the potential association between various measures of exposure of dental diseases and predictors of cardiovascular risk (c-IMT > 0.9 mm and presence of plaque or their combination). Results: Diagnosis of periodontitis (OR 6.71, 95% CI: 2.68-16.76, P < 0.001), cumulative mucosal/gingival inflammation (Periodontal Screening and Recording score) (OR 1.25, 95% CI:1.12-1.41, P < 0.001), and mucositis (OR 3.34, 95% CI:1.13-9.85, P < 0.05) were associated with c-IMT > 0.9 mm and/or plaque presence independent of age, sex, smoking, 24 h systolic blood pressure and body mass index differences. No statistically significant results were noted for peri-implantitis. Linear regression models confirmed a positive association of cumulative mucosal/gingival inflammation (β = 0.011, SE 0.002, P < 0.001), diagnosis of periodontitis (β = 0.114, SE 0.020, P < 0.001), and peri-implant diseases (β = 0.011, SE 0.002, P < 0.001) with increased c-IMT values. Conclusions: This study confirms a positive association between mucosal/gingival inflammation and subclinical atherosclerosis assessed by c-IMT values and the presence of carotid plaque in patients with hypertension, independent of traditional cardiovascular risk factors. Future studies are needed to further characterize this relationship

    Association between subclinical atherosclerosis and oral inflammation: A cross-sectional study

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    Background: The aim of this cross-sectional study was to investigate the association between carotid intima-media thickness (c-IMT) values and periodontal and peri-implant diseases in a sample of patients with hypertension. Methods: A total of 151 participants with presence of at least one dental implant in function for >5 years were recruited. Anthropometric measurements, 24-h ambulatory blood pressure monitoring, ultrasound assessment of carotid arteries (c-IMT and presence of plaque) were recorded and venous blood samples obtained. An oral examination was performed by calibrated examiners to ascertain prevalence and severity of periodontal and peri-implant diseases. Binomial logistic regression was performed to investigate the potential association between various measures of exposure of dental diseases and predictors of cardiovascular risk (c-IMT > 0.9 mm and presence of plaque or their combination). Results: Diagnosis of periodontitis (OR 6.71, 95% CI: 2.68-16.76, P  0.9 mm and/or plaque presence independent of age, sex, smoking, 24 h systolic blood pressure and body mass index differences. No statistically significant results were noted for peri-implantitis. Linear regression models confirmed a positive association of cumulative mucosal/gingival inflammation (β = 0.011, SE 0.002, P < 0.001), diagnosis of periodontitis (β = 0.114, SE 0.020, P < 0.001), and peri-implant diseases (β = 0.011, SE 0.002, P < 0.001) with increased c-IMT values. Conclusions: This study confirms a positive association between mucosal/gingival inflammation and subclinical atherosclerosis assessed by c-IMT values and the presence of carotid plaque in patients with hypertension, independent of traditional cardiovascular risk factors. Future studies are needed to further characterize this relationship
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