5,211 research outputs found

    CUB models: a preliminary fuzzy approach to heterogeneity

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    In line with the increasing attention paid to deal with uncertainty in ordinal data models, we propose to combine Fuzzy models with \cub models within questionnaire analysis. In particular, the focus will be on \cub models' uncertainty parameter and its interpretation as a preliminary measure of heterogeneity, by introducing membership, non-membership and uncertainty functions in the more general framework of Intuitionistic Fuzzy Sets. Our proposal is discussed on the basis of the Evaluation of Orientation Services survey collected at University of Naples Federico II.Comment: 10 pages, invited contribution at SIS2016 (Salerno, Italy), in SIS2016 proceeding

    Minimum bias and soft QCD ATLAS results

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    Soft-QCD measurements in proton-proton collisions at √s = 900 GeV and √s = 7TeV recorded with the ATLAS detector at the LHC using a single-arm minimum bias trigger are presented. The charged particle multiplicity distribution, its dependence on transverse momentum and pseudorapidity and its correlation with the average transverse momentum will be shown. Moreover, the measurement of the underlying event properties using charged particles is discussed. Finally the measurement of the angular correlations between charged particles is presented. All the measurements are compared with Monte Carlo predictions

    Laser microgrooved vs. machined healing abutment disconnection/reconnection: a comparative clinical, radiographical and biochemical study with split-mouth design

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    Background: Repeated removal and replacement of healing abutments result in frequent injuries to the soft tissues.Purpose: The purpose of this study was to evaluate the effect of disconnection/reconnection of laser microgrooved vs. machined healing and prosthetic abutments on clinical periodontal parameters, marginal bone levels, and proinflammatory cytokine levels around dental implants.Material and methods: Twenty-four patients each received 2 implants with one-stage protocol in a split-mouth design on the same jaw. In each patient, one healing and prosthetic abutments with a laser microgrooved surface (LMS group) and one healing and prosthetic abutments with machined surface (MS group) were used. Four months following implant placement (T0), the healing abutments were disconnnected and reconnected three times to carry out the impression procedures and metal framework try-in. Four weeks later (T1), definitive prosthetic abutments were installated with screw-retained crowns. Modified plaque index (mPI), modified gingival index (mGI) bleeding on probing (BOP), and probing depth (PD) were recorded at T0 and T1. At the same time points, samples for immunological analyses were taken from the sulcus around each implant. Peri-implant crevicular fluid (PICF) samples were analyzed for interleukin-1beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor (TNF)-alpha levels using the ELISA kit.Results: At T0 and T1, mPI and mGI showed no statistical difference between the two groups, while higher PD and BoP values were noted for the MS group (P < 0.05). The mean PICF volume and mean concentrations of IL-1 beta, IL-6, and (TNF)-alpha in the LMS group were statistically less than those in the MS group (P < 0.05). In addition, comparison of IL-6 and IL-1 beta mean concentrations at T0 and T1 in the MS group showed a statistically significant increase (p < 0.05) over time, which was not noted for the LMS.Conclusion: Disconnection/reconnection of healing and prosthetic abutments with a laser-microgrooved surface resulted in less inflammatory molecular response compared with conventional machined ones

    Changes of radiographic trabecular bone density and peri-implant marginal bone vertical dimensions around non-submerged dental implants with a laser-microtextured collar after 5 years of functional loading

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    Objectives: The progressive peri-implant bone remodeling caused by dynamic cycles of microdamage may change peri-implant bone characteristics and volume after the functional loading. This prospective study was designed to evaluate the radiographic trabecular bone density and peri-implant vertical dimensional changes around the non submerged dental implant with a laser-microtextured collar (NSLI)s after 5 years of functional loading. Methods: Digital periapical radiographs of 58 NSLIs supported fixed single crowns and fixed partial dentures in 26 patients (14 men, mean age of 52 ± 3.8 years) were used for comparative evaluation between the implant placement [Baseline (BSL)], the definitive Crowns Delivery (CD) and the 5 years post-functional loading examination (T5). Regions of interest (ROI) were taken into consideration for the measurement of mean gray levels, standard deviation, and variation coefficient. The texture parameters, such as contrast, correlation, angular second moment and entropy, were investigated by using the software ImageJ (v.1.50i), by means of the Gray-level Co-occurrence Matrix (GLCM) Texture Tool plugin. Vertical Periimplant Marginal Bone Level (VPMBL) was assessed at the mesial and the distal sides of each implant by subtracting the measure at BSL from the measure at T5 by means of dedicate software (VixWin Platinum Imaging Software). Mixed regression models were adopted to analyze data. The possible effects of some variables, such as the use of provisional denture, location, crown/implant ratio, type of prosthetic design (single or splinted), on radiographic dimensional vertical changes, gray levels and texture analysis variables were also evaluated. Results: From BSL to T5, mesial and distal VPMBL showed a statistically significant gain of 0.9 ±0.5, and 0.10 mm ±0.6, respectively (P<0.05). From CD to T5, mean gray levels increased from 94.4±26.8) to 111.8±27.1 (P<0.05), while the coefficient of variation decreased from 0.08±0,03 to 0.05±0.04) (P<0.05). Variables showed no statistically significant correlation with texture parameters (P > 0.05). Conclusion: NSLIs showed an increase in radiographic vertical peri-implant marginal bone levels and bone density up to 5 years of loading

    Thermal Conductivity Enhancement of Al2O3 Nanofluid in Ethylene Glycol and Water Mixture

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    AbstractThe ability of nanofluids that exhibits enhanced thermal performance is acknowledged by researchers through studies since decades ago. However, the observation of thermal properties for nanofluids in water and ethylene glycol based is not fully explored yet. Hence, this paper presents the thermal conductivity of water and ethylene glycol (EG) based Al2O3 nanofluid. The 13 nm sized Al2O3 nanoparticles were dispersed into three different volume ratio of water: EG such as 40:60, 50:50 and 60:40 using a two-step method. The measurement of thermal conductivity was performed using KD2 Pro Thermal Properties Analyzer at working temperatures of 30 to 70 ÌŠC for volume concentration of 0.5 to 2.0%. The results indicate that the thermal conductivity increases with the increase of nanofluid concentration and temperature. While the percentage of ethylene glycol increase, the range of thermal conductivity decreases due to ethylene glycol properties. The measurement data of the nanofluids give maximum enhancement of thermal conductivity at condition 2.0% volume concentration, temperature of 70 ÌŠC and for all base fluid

    Zinc oxide non-eugenol cement versus resinous cement on single implant restoration: a split-mouth study

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    Cement-retained implant restorations still represents a widely used prosthetic solution today, considering the simple execution, the possibility of correcting the implant axis according to the dental axis and an extremely satisfactory aesthetic. The objective of the study is to evaluate whether resin-based cements are actually more aggressive towards the peri-implant tissue compared to zinc oxide cements. In the present study 18 patients (8 males and 10 females) were examined with a split-mouth design. The follow-up period for patients after delivery of the cement-retained single crown is a maximum of 48 months. A total of 36 implants were inserted and monitored during this period. Clinical and radiographic tests were carried out on all 36 implants, with constant re-evaluation, as well as the occurrence of some prosthetic or biological problems that brought the patient back to visit. The results for both cements were in line with the indications of the respective manufacturers. During the observational period, no implant failed, with a survival rate of 100% on these 36 implants. In conclusion, it is possible to establish that the number of decementations of the cement-retained crowns cemented with Temp Bond non-eugenol was higher, but not statistically significant. In contrast, the biological complications per implant and the MBL were significantly higher in the cement-retained crowns cemented with Implacem
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