268 research outputs found

    Survival rate of indirectly bonded brackets using single vs. two-component orthodontic adhesive: A 12-month split-mouth clinical trial

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    Objective: Compare the bonding survival rate of two distinct bonding materials: Ortho Solo + Gradia LoFlo Resin and single component GC Ortho Connect. Materials and Methods: Indirect bonding fixed appliance treatment was required for 26 consecutive patients, 8 males and 18 females, with a mean age of 22.1 +/- 4.2 years. All patients were treated with SWM (Straight-Wire Mirabella) technique (Sweden and Martina, Due Carrare, Padova, Italy). Each patient's bonding process followed a contralateral pattern. Firstly, a 37 % orthophosphoric acid etching gel was used for 20 s, subsequently the single or two components light-cured adhesives were applied through a split-mouth cross-arch procedure. The patients underwent a 12-month follow-up period and brackets failures were rebounded, but not further included in the study. Statistical analysis was performed to analyse the survival rate of the bonding materials and the influence of the variables, with a significant level of α = 0,05. Results: The GC Connect group was used on 349 teeth, while the Ortho Solo + Gradia group was used on 351 teeth, and the indirect debonding rate was respectively 17.5% and 12.8%. With respect to the total sample, statistically significant values were found for both sex and dental arch. The bracket's survival rate for incisors, canines, premolars and molars was not significant. However, a higher debonding rate was clinically appreciable in upper and lower molars. Conclusion: In a 12-months observation period, considering all maxillary and mandibular teeth the indirect survival rate for the group GC Ortho Connect and Ortho Solo + Gradia was respectively 82.5% and 87.2%. Although the difference was not significant, a pronounced tendency to debonding for the single component group was appreciable from a clinically point of view

    Dynamic reconfiguration of electrical connections for partially shaded PV modules: Technical and economical performances of an Arduino-based prototype

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    The partial shading phenomenon is a well known problem of photovoltaic plants. Partial shading leads to undesirable effects such the electrical mismatch, the generation of hot spots, and generally the decrease of production of electric energy. To mitigate the last effect, a dynamic reconfiguration of the electrical connections between modules was taken into account. In this paper, starting from an already developed system for a small-scale photovoltaic plant reconfiguration, the study of the economical benefits of the employment of a reconfigurator are traced. Five different incentive policies of diverse Countries have been considered to evaluate the increase of Net Present Value of system with and without a reconfigurator

    Power bus management techniques for space missions in low earth orbit

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    In space vehicles, the typical configurations for the Solar Array Power Regulators in charge of managing power transfer from the solar array to the power bus are quite different from the corresponding devices in use for terrestrial applications. A thorough analysis is reported for the most popular approaches, namely Sequential Switching Shunt Regulation and parallel-input Pulse Width Modulated converters with Maximum Power Point Tracking. Their performance is compared with reference to a typical mission in low Earth orbit, highlighting the respective strengths and weaknesses. A novel solar array managing technique, the Sequential Maximum Power Tracking, is also introduced in the trade-off and was demonstrated able to boost energy harvesting, especially in the presence of mismatching in the solar array. It also can achieve top levels of reliability using a rather simple control hardware. Its operation was verified both by a Matlab–Simulink model and by an experimental breadboard

    Recycling of a multilayer barrier food packaging through the use of a nanofiller: Effect of post-consumer plastic bag conditions

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    Barrier food packaging films result very difficult to recycle since they are multilayer films composed by at least two different materials. In this context, aim of this study was to assess the use of a nanofiller for the mechanical recycling of multilayer barrier plastic bags used for food vacuum packaging. In particular, graphene nanoplatelets (GnPs) were used as nanofiller studying the effect of their concentration on the properties of the nanocomposites obtained by using polyamide (PA)/polyethylene (PE) bags as polymeric matrix. Moreover, the effect of plastic bags life conditions on the nanocomposite properties were evaluated by exposing the multilayer films to accelerated weathering or to contact with a fatty food simulant (olive oil). The results indicated that the incorporation of GnPs led to an enhancement of the morphology of the polymer blends, consequently resulting in nanocomposites with increased stiffness without a drastic reduction in ductility. The nanocomposites produced using post-consumer bags exhibited lower properties compared to materials produced using pre-consumer bags. However, even in this case, the addition of GnPs contributed to an improvement in the properties demonstrating that the use of this nanofiller can be a viable method to recycle multilayer packaging

    Creutzfeldt-Jakob disease after COVID-19: infection-induced prion protein misfolding? A case report

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    Creutzfeldt-Jakob disease (CJD) is a rare, fatal disease presenting with rapidly progressive neurological deficits caused by the accumulation of a misfolded form (PrPSc) of prion protein (PrPc). Coronavirus disease 2019 (COVID-19) is a primarily respiratory syndrome caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); many diverse neurological complications have been observed after COVID-19. We describe a young patient developing CJD two months after mild COVID-19. Presenting symptoms were visuospatial deficits and ataxia, evolving into a bedridden state with preserved consciousness and diffuse myoclonus. Diagnostic work-up was suggestive of CJD. The early age of onset and the short interval between respiratory and neurological symptoms might suggest a causal relationship: a COVID-19-related neuroinflammatory state may have induced the misfolding and subsequent aggregation of PrPSc. The present case emphasizes the link between neuroinflammation and protein misfolding. Further studies are needed to establish the role of SARS-CoV-2 as an initiator of neurodegeneration

    Multisensory mental representation in covid-19 patients and the possibility of long-lasting gustatory and olfactory dysfunction in the CNS

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    Gustatory (GD) and olfactory (OD) dysfunctions are the most frequent neurological manifestations of COVID-19. We used mental imagery as an experimental psychological paradigm to access olfactory and gustatory brain representations in 80 Italian COVID-19 adult patients (68.75% reported both OD and GD). COVID-19 patients with OD + GD have a significantly and selectively decreased vividness of odor and taste imagery, indicating that COVID-19 has an effect on their chemosensory mental representations. OD + GD length and type influenced the status of mental chemosensory representations. OD + GD were become all COVID-19 negative at the time of testing. Data suggest that patients are not explicitly aware of long-term altered chemosensory processing. However, differences emerge when their chemosensory function is implicitly assessed using self-ratings. Among patients developing OD + GD, self-ratings of chemosensory function (taste, flavor) were significantly lower as compared to those who did not. At the level of mental representation, such differences can be further detected, in terms of a reduced ability to mentally activate an odor or taste mental image. Our study shows that COVID-19 infection not only frequently causes hyposmia and dysgeusia, but that may also alter the mental representations responsible for olfactory and gustatory perception

    Experimental study on B-spline-based modulation schemes applied in multilevel inverters for electric drive applications

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    This work presents the design, simulation, and experimental validation of new B-Spline-based modulation techniques applied to a Multilevel Power Inverter (MPI), particularly focusing the attention on the harmonic content of the output voltages of the inverter. Simulation and experimental results are proposed and discussed, mainly describing the potential benefits, such as the increase of the multi-level operation of the converter, and drawbacks (low-order harmonics) related to the adoption of B-Spline functions for multilevel inverters applied in the field of electrical drives

    Comparison of topical tacrolimus 0.1 % in pectin ointment with clobetasol 0.5% ointment in adults with moderate to severe desquamative gingivitis: A 4-week, randomized, double-blind clinical trial.

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    BACKGROUND: Desquamative gingivitis (DG) is a clinical condition characterized by red, painful, glazed, and friable gingiva, which might be a manifestation of some autoimmune mucocutaneous diseases. The time from the development of initial signs of DG to diagnosis can vary from months to years. Based on a literature search, no data concerning patients with DG without signs of autoimmune disease were available. OBJECTIVE: The aim of this trial was to compare the efficacy and tolerability of monotherapy with topical tacrolimus 0.1% in pectin ointment versus clobetasol propionate 0.5% ointment in adults affected by DG. METHODS: This randomized, double-blind clinical trial was conducted at the Dipartimento di Medicina Clinica e Sperimentale, Universita di Verona, Verona, Italy. Patients aged > or =18 years were selected using the department's electronic medical records based on a clinical diagnosis of moderate to severe DG. After a 2-week washout period, patients were randomly assigned to receive 2 mL of tacrolimus 0.1% in pectin (equivalent to 0.2 mg of tacrolimus) or 2 mL of clobetasol propionate 0.5% ointment (equivalent to 1 mg of clobetasol) QD for 4 weeks. Evaluations were performed before treatment (baseline), after the treatment period (week 4), and at 2 follow-up visits at weeks 6 and 8. The signs of DG (ie, erythema [atrophy] and desquamation [erosions/ulceration]) were quantified by a blinded investigator using a calculated score based on their surface extension, using a drawing in which the areas of various zones of the mouth were indicated as a percentage of the whole oral mucosa. Severity of erythema and desquamation was rated on a 4-point scale (0 = absent; 1 = involvement of 15% [severe]). The primary end point was the number of patients who achieved remission (severity score of 0) in either sign; the secondary end point was the proportions of patients achieving improvement (severity score of 0 or 1) in either sign. Before and after treatment, we measured the serum concentrations of tacrolimus and its metabolites with an immunoenzymatic assay kit. Tolerability was assessed using hematology, biochemistry, urinalysis, measurements of systolic/diastolic blood pressure and heart rate, patient interview, and spontaneous reporting. RESULTS: A total of 24 patients (18 women, 6 men; all white of Italian origin; age range, 21-65 years; 12 patients per treatment group) were enrolled in the study. In the tacrolimus group, 11 (91.7%) patients achieved remission of erythema and/or desquamation at weeks 4 and 6; at week 8, these rates were 9 (75.0%) and 8 (66.7%), respectively; none of the patients in the clobetasol group achieved remission of either sign at any time point (all, P < 0.001). At weeks 4, 6, and 8, significantly greater proportions of patients treated with tacrolimus had improved erythema and desquamation compared with those treated with clobetasol (all, P < 0.001). At week 4, all patients had undetectable serum tacrolimus concentrations (<1.5 microg/L). Six (50.0%) patients in the tacrolimus group reported a mild oral burning sensation, and 6 (50.0%) patients in the clobetasol group reported mild mouth dryness. No other adverse events were reported. CONCLUSIONS: The results of this small study suggest that topical tacrolimus 0.1 % in pectin was more effective compared with clobetasol propionate 0.5% ointment in the treatment of DG. Both treatments were generally well tolerated in the population studied

    Randomized placebo-controlled trial comparing desloratadine and montelukast in monotherapy and desloratadine plus montelukast in combined therapy for chronic idiopathic urticaria

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    BACKGROUND: H 1 -receptor antagonists are considered to be particularly effective in reducing pruritus, and they are therefore recommended as first-line treatment in patients with chronic idiopathic urticaria (CIU). Recently, antileukotriene receptors have been used in patients with CIU, either administered as monotherapy or combined with H 1 -receptor antagonists. OBJECTIVE: We compared the clinical efficacy of 5 mg of desloratadine administered once daily either as monotherapy or combined with a leukotriene antagonist, 10 mg of montelukast daily, and 10 mg of montelukast administered daily as monotherapy for the treatment of patients affected by CIU with placebo. METHODS: One hundred sixty patients aged 18 to 69 years (mean +/- SD, 43.9 +/- 13.4 years) with a history of moderate CIU were selected. A randomized, double-blind, double-dummy, placebo-controlled, parallel-group study design was used. Patients were treated with 5 mg of desloratadine once daily (n = 40), 10 mg of montelukast once daily (n = 40), 5 mg of desloratadine (n = 40) in the morning plus montelukast in the evening, or matched placebo (n = 40). Assessment of treatment efficacy was based on scores of daily cutaneous symptoms evaluated reflectively and instantaneously. RESULTS: Only the group treated with desloratadine as monotherapy or as combined therapy concluded the whole study. Twenty-seven of the 40 patients in the montelukast group and 35 of the 40 patients in the placebo group discontinued the treatment. As reflective evaluation, all groups showed significant differences compared with the placebo group in terms of total symptom score, number of hives, and size of largest hive. In addition to the pruritus, only the groups treated with desloratadine as monotherapy or combined therapy showed significant differences compared with those receiving placebo, whereas there were no differences between the montelukast and placebo groups. Finally, no differences were found between the desloratadine group and the desloratadine plus montelukast group. The instantaneous evaluation demonstrated similar results regarding the desloratadine group and the desloratadine plus montelukast group versus the placebo group, whereas there were no significant differences between the group treated with montelukast alone and the placebo group for pruritus and size of largest hive. No differences were found between the group treated with desloratadine alone and the desloratadine plus montelukast group. CONCLUSIONS: The results of this comparative study demonstrate that desloratadine is highly effective for the treatment of patients affected by CIU. In addition, the regular combined therapy of desloratadine plus montelukast does not seem to offer a substantial advantage with respect to desloratadine as monotherapy in patients affected by moderate CIU
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