309 research outputs found

    A new design approach to the use of composite materials for heavy transport vehicles

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    In order to keep or to reach a high level of competitiveness and performance of a product, it is necessary to explore all the possible solutions that allow the best compromise between costs and project requirements. By this point of view the study of alternative designs and/or materials to use, is an important aspect that can identify a new concept or way of thinking about a product. This paper presents how to make use of composite materials in the field of heavy vehicles transportation. A new semitrailer in composite material has been designed, using a methodical redesign approach and an optimisation process. The main innovation in this project is, besides the use of the Glass Fibre Reinforced Plastics (GFRPs), also a new topology of the vehicle frame; the designed semitrailer, in fact. has a monocoque structur

    Urban landscape evolution as a consequence of an invasive pest: The case of a small sicilian town

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    The Red Palm Weevil (RPW), after its accidental introduction in Italy in 2005, determined a progressive disruption of Canary palms mostly in the central and southern regions. As it is difficult to undertake the management of this pest, the possibility of substituting the killed/symptomatic palms with other ornamental trees has been recently discussed. In this context, understanding the citizens' needs about green areas can improve the management of public parks and urban greening. Involving citizens on the natural resource management using public participation processes is crucial. The case study of a small town of Sicily (Italy) was treated and the spread of this pest was monitored. Moreover, the possibility of substituting the killed palms with other ornamentals was discussed by involving a sample of the population through a direct survey aimed at detecting the preferences in respect to certain tree species (as potential substitutes of the killed palms) listed in a questionnaire administered face-to-face. The citizen's samples showed great interest in the green areas (97%) and indicated a traditional Mediterranean plant as Nerium oleander as the preferred palm substitute candidate

    Virtual reality and live scenario simulation: options for training medical students in mass casualty incident triage

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    Introduction Multicasualty triage is the process of establishing the priority of care among casualties in disaster management. Recent mass casualty incidents (MCI) revealed that health personnel are unfamiliar with the triage protocols. The objective of this study is to compare the relative impact of two simulation-based methods for training medical students in mass casualty triage using the Simple Triage and Rapid Treatment (START) algorithm. Methods A prospective randomized controlled longitudinal study. Medical students enrolled in the emergency medicine course were randomized into two groups (A and B). On day 1, group A students were exposed to a virtual reality (VR) scenario and group B students were exposed to a live scenario (LS), both exercises aiming at triaging 10 victims in a limited period of time (30 seconds/victim). On day 2 all students attended a 2-hour lecture about medical disaster management and START. On day 3 group A and B students were exposed to a LS and to a VR scenario respectively. The vital signs and clinical condition of the 10 victims were identical in the two scenarios. Ability of the groups to manage a simulated triage scenario was then compared (times and triage accuracy). Results Groups A and B were composed of 25 and 28 students respectively. During day 1 group A LS triage accuracy was 58%, while the average time to assess all patients was 4 minutes 28 seconds. The group B VR scenario triage accuracy was 52%, while the average time to complete the assessment was 5 minutes 18 seconds. During day 3 the triage accuracy for group A VR simulation was 92%, while the average time was 3 minutes 53 seconds. Group B triage accuracy during the LS was 84%, with an average time of 3 minutes 25 seconds. Triage scores improved significantly during day 3 (P < 0.001) in the two groups. The time to complete each scenario decreased significantly from day 1 to day 3. Conclusions The study demonstrates that the training course generates significant improvement in triage accuracy and speed. It also reveals that VR simulation compared to live exercises has equivalent results in prompting critical decisions in mass casualty drills. In the beginning the average time to complete the VR scenario was higher than the LS. This could be due to the fact that on day 1 very detailed VR victims created a higher challenge for untaught students. However, the higher triage accuracy recorded at the end of day 3 in VR could be explained by a lower stress level compared to the LS, which could be creating a more stressful environment in taught students

    The impact of fixed triple therapy with beclometasone/formoterol/glycopyrronium on health status and adherence in chronic obstructive pulmonary disease (COPD) in an italian context of real life: The TRITRIAL study protocol

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    Background: The fixed triple combination Beclometasone dipropionate/Formoterol fuma- rate/Glycopyrronium (BDP/FF/G, Trimbow\uae), an extrafine formulation in a unique pressur- ized metered dose inhaler, is indicated for the maintenance treatment in adult patients with moderate to severe COPD, not adequately treated by ICS/LABA or LABA/LAMA. Besides the evidence from three randomized controlled trials, the impact of fixed triple therapy has not been extensively evaluated in a real-world population of COPD patients. TRITRIAL (TRIple Therapy in Real life: Impact on Adherence and HeaLth status) is a non- interventional study to assess the effect of BDP/FF/G in a real world setting in Italy. Design: TRITRIAL is a 12-month, multicenter, cohort, prospective, longitudinal observational study. Two follow-up visits will be performed at 6 and 12 months, respectively. The study includes the collection of anamnestic clinical and functional data before the start of BDP/FF/G. The study is built for digital conduction, from signature of the informed consent on a dedicated web platform, to the collection of questionnaires and clinical data on the eCRF. Population: A total of 800 patients with COPD ranging from Global Initiative for Obstructive Lung Disease (GOLD) stages 2 to 4, receiving therapy with BDP/FF/G accord- ing to the Summary of Product Characteristics and local clinical practice, will be recruited. All concomitant therapies will be permitted for the duration of the study. Evaluations: The primary endpoint is the change of CAT score at 12 months versus baseline. Secondary endpoints are adherence, health-related quality of life, sleep quality, disease-related outcomes (lung function and COPD exacerbations), device usability, eco- nomic resources consumption, and safety. Conclusion: TRITRIAL study is expected to give relevant information about effectiveness of BDP/FF/G fixed triple therapy in a real-life setting of patients with COPD, where adherence, usability of inhalers and patient\u2019s preference of the device are crucial factors for the success of the therapy

    Study of a constrained finite element elbow prosthesis: the influence of the implant placement

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    Background: The functional results of total elbow arthroplasty (TEA) are controversial and the medium- to long-term revision rates are relatively high. The aim of the present study was to analyze the stresses of TEA in its classic configuration, identify the areas of greatest stress in the prosthesis–bone–cement interface, and evaluate the most wearing working conditions. Materials and methods: By means of a reverse engineering process and using a 3D laser scanner, CAD (computer-aided drafting) models of a constrained elbow prosthesis were acquired. These CAD models were developed and their elastic properties, resistance, and stresses were studied through finite element analysis (finite element method—FEM). The obtained 3D elbow-prosthesis model was then evaluated in cyclic flexion–extension movements (&gt; 10 million cycles). We highlighted the configuration of the angle at which the highest stresses and the areas most at risk of implant mobilization develop. Finally, we performed a quantitative study of the stress state after varying the positioning of the stem of the ulnar component in the sagittal plane by ± 3°. Results: The greatest von Mises stress state in the bone component for the 90° working configuration was 3.1635&nbsp;MPa, which occurred in the most proximal portion of the humeral blade and in the proximal middle third of the shaft. At the ulnar level, peaks of 4.1763&nbsp;MPa were recorded at the proximal coronoid/metaepiphysis level. The minimum elastic resistance and therefore the greatest stress states were recorded in the bone region at the apex of the ulnar stem (0.001967&nbsp;MPa). The results of the analysis for the working configurations at 0° and 145° showed significant reductions in the stress states for both prosthetic components; similarly, varying the positioning of the ulnar component at 90° (−&nbsp;3° in the sagittal plane, 0° in the frontal plane) resulted in better working conditions with a greater resulting developed force and a lower stress peak in the ulnar cement. Conclusion: The areas of greatest stress occur in specific regions of the ulnar and humeral components at the bone–cement–prosthesis interface. The heaviest configuration in terms of stresses was when the elbow was flexed at 90°. Variations in the positioning in the sagittal plane can mechanically affect the movement, possibly resulting in longer survival of the implant. Level of evidence:

    Evaluation of acute cardiovascular effects of immediate-release methylphenidate in children and adolescents with attention-deficit hyperactivity disorder

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    Attention-deficit hyperactivity disorder is a frequent condition in children and often extends into adulthood. Use of immediate-release methylphenidate (MPH) has raised concerns about potential cardiovascular adverse effects within a few hours after administration. This study was carried out to investigate acute effects of MPH on electrocardiogram (ECG) in a pediatric population. A total of 54 consecutive patients with attention-deficit hyperactivity disorder (51 males and 3 females; mean age =12.14±2.6 years, range 6–19 years), receiving a new prescription of MPH, underwent a standard ECG 2 hours before and after the administration of MPH 10 mg per os. Basal and posttreatment ECG parameters, including mean QT (QT interval when corrected for heart rate [QTc]), QTc dispersion (QTd) interval duration, T-peak to T-end (TpTe) intervals, and TpTe/QT ratio were compared. Significant modifications of both QTc and QTd values were not found after drug administration. QTd fluctuated slightly from 25.7±9.3 milliseconds to 25.1±8.4 milliseconds; QTc varied from 407.6±12.4 milliseconds to 409.8±12.7 milliseconds. A significant variation in blood pressure (systolic blood pressure 105.4±10.3 vs 109.6±11.5; P&lt;0.05; diastolic blood pressure 59.2±7.1 vs 63.1±7.9; P&lt;0.05) was observed, but all the data were within normal range. Heart rate moved from 80.5±15.5 bpm to 87.7±18.8 bpm. No change in TpTe values was found, but a statistically significant increase in TpTe/QTc intervals was found with respect to basal values (0.207±0.02 milliseconds vs 0.214±0.02 milliseconds; P&lt;0.01). The findings of this study show no significant changes in ECG parameters. TpTe values can be an additional parameter to evaluate borderline cases

    Detection of Antibodies to Human Herpesvirus 8 (HHV-8) among Women of Child-Bearing Age in the Apulia Region (South-Eastern Italy):

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    In this study the authors investigated the presence of serum antibodies to Human Herpesvirus 8 (HHV-8) in a group of women of child-bearing age in the Apulia region (South Eastern Italy). A seroprevalence of 16.8% was observed, increasing, although non significantly, with the age of the women (10.6% in women between 19 and 25 years, 25.3% in women aging more than 35 years). The presence of antibodies to Hepatitis C Virus (HCV) was significantly associated to the detection of antibodies to HHV-8. Possible mother-to-child transmission of HHV-8 as well as the outcome of fetuses or children born to HHV-8 positive mothers are still a matter of debate. This study, showing the wide diffusion of HHV-8 infection in healthy women of child-bearing age in our geographical area, highlights the urgency of studies aimed to better clarify these relevant topics

    Mechanical behavior of a sandwich with corrugated GRP core: numerical modeling and experimental validation

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    In this work the mechanical behaviour of a core reinforced composite sandwich structure isstudied. The sandwich employs a Glass Reinforced Polymer (GRP) orthotropic material for both the twoexternal skins and the inner core web. In particular, the core is designed in order to cooperate with the GRPskins in membrane and flexural properties by means of the addition of a corrugated laminate into the foamcore. An analytical model has been developed to replace a unit cell of this structure with an orthotropicequivalent thick plate that reproduces the in plane and out of plane behaviour of the original geometry.Different validation procedures have been implemented to verify the quality of the proposed method. At first acomparison has been performed between the analytical model and the original unit cell modelled with a FiniteElement mesh. Elementary loading conditions are reproduced and results are compared. Once the reliability ofthe analytical model was assessed, this homogenised model was implemented within the formulation of a shellfinite element. The goal of this step is to simplify the FE analysis of complex structures made of corrugatedcore sandwiches; in fact, by using the homogenised element, the global response of a real structure can beinvestigated only with the discretization of its mid-surface. Advantages are mainly in terms of time to solutionsaving and CAD modelling simplification. Last step is then the comparison between this FE model andexperiments made on sandwich beams and panels whose skins and corrugated cores are made of orthotropiccross-ply GRP laminates. Good agreement between experimental and numerical results confirms the validity ofthe proposed model
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