111 research outputs found

    Application of FMEA method for assessment of reliability of structures

    Get PDF
    In the last years several methods have been proposed, aimed to explore the theme of degradation and reliability of building components, with the main purpose of preventing performance deficits in general, and especially from sudden and unforeseen faults. This topic is an element of strong competitiveness in the world of professionals and business, and fits with the trend clearly demonstrated by the regulatory framework, particularly in the field of structures. One of the methods that can be used to assess the suitability of a component to its performance specifications, and which belongs to the field of Risk Management, is FMEA, (Failure Modes and Effects Analysis). This methodology analyzes a project from the point of view of its reliability before it is carried out and realized.To allow this verification the components are firstly verified in the form of drawings, technical specifications, flow-charts, information, standards, etc. that are all the elements that make up the documentation of the work to be performed and the knowledge that is available on the subject. There have been many applications of FMEA on building components, and it is of particular interest - considering the recrudescence of seismic events of the last decade, but also the emergence of structural defects, even of a certain gravity – for the use in the field of structures. This is of a considerable relevance in a period when there are issues about the possibility of adaptation of the real estate to earthquakes, but it also raises the argument of the modalities and the criteria leading the inevitable reconstruction of what no longer exists. In this article an example of application to a reinforced concrete structure is shown, from which it is possible to notice the most critical items and the modalities for preventing negative events

    Performance characterization of the concrete subjected to fire in terms of sustainability

    Get PDF
    The research, in a context of a sustainability of the building process, that should consider adequately the problem of building waste disposal, has the objective of determining the performance characteristics of concrete under the effect of fire, in order to evaluate the possibility of reutilization, and in positive case, what could the best uses be, considering the current regulations. The experimentation, carried out on cubic samples with a side of 15 cm (according to UNI EN 12390, using aggregates with Dmax= 30 mm), with Portland cement of mixture 42,5 in two types (one with Pozzolana CEM II/B-P 42.5 and one with limestone CEM II/A-LL 42.5), with class of resistance C25/30, is based on the following parameters: increase of temperature, nature of fire, heating speed, time of exposition. The tests that have been carried out were both destructive (sclerometric, ultrasounds, Sonreb) and non-destructive (crushing and thermogravimetric), and the experimental results obtained also show that: - the concretes present a remaining mechanical resistance that is lower than 50% of the initial one, after they have been subjected to the full cycle of temperature increase; - between 200°C and 600°C, there is a significant decomposition of the binding component (hydrated cement), while that of limestone is predictable for temperatures higher than 700°C; - the phenomenon of the “explosive spalling” – verified on two samples – has far more devastating consequences than the simple decay of the mechanical characteristics as, considered in a structural element, it causes a reduction of the resisting section, with a consequential increase of tensions in the remaining part, and direct exposition of the reinforcement without protection, situations which can cause the structural collapse of the element. Some uses in the field of transport have been hypothesized, also basing on the indications of the current regulations and on the detected statistics of the current uses

    MULTICRITERIA ANALYSIS FOR CHOOSING MAINTENANCE STRATEGIES

    Get PDF
    The life cycle of building components can be managed according to different maintenance strategies, which mainly differ in performance and economic terms. What is the most convenient among the possible scenarios? It has been shown in the past that the typology of maintenance interventions and the consequent periodicity are closely related to performance decay, and can lead to choices that, however, generally concern the purely economic sphere. In this sense, it seems interesting to know the modalities of the performance decay, which may allow – even though for many components the "measurement" of its values is problematic - the construction of performance / time curves. This result was possible, in other experiments conducted in the past, for one of the components to be considered most critical for the whole building (the plaster), thanks to a study that sampled 53 buildings with homogeneous characteristics (both from the technological point of view and from the era of realization), observed within 20 years. This paper highlights that the only economic evaluation is not enough to identify the ideal solution, because – inter alia - there is a more suitable solution depending on the context framework in which the decision maker is operating. Commitment, budget, component typology, time span to consider, are the main factors influencing the choice, not ignoring design issues. A Topsis multicriteria analysis is proposed, the results of which are an interesting starting point for define maintenance plans characterized by greater reliability, not only technical but also economical

    LCC analysis for glued laminated timber components exposed in external

    Get PDF
    The aim of the experimentation is to characterize the performances of glued laminated timber components exposed to atmospheric agents, in the light of the concept of Life Cycle Cost, particularly emphasized in the Italian new legislation on public works. In fact, it could be seen that the design of the construction details and the initial characteristics of glue laminated timber components, require a particular attention to avoid errors that may undermine the possibility to perform the structural functions for which, above all, this material it is dedicated. The experimentation consisted of a series of tests aimed to identify the performance of glued laminated timber beams taken in site, after a work executed some years ago on a theatre built in Roman era, and to compare them with similarly manufactured new elements. The tests performed were thermography, ultrasound, Wood-Pecker penetrometer, mechanical characterization. The results will be used to begin setting limits and conditions for outdoor use of glue laminated timber, and assume a reliable life cycle, and consequently identify the most appropriate maintenance strategy for the LCC

    Deregulation of cancer-stem-cell-associated miRNAs in tissues and sera of colorectal cancer patients

    Get PDF
    Colorectal cancer (CRC) is a deadly tumour in Western countries characterized by high cellular/molecular heterogeneity. Cancer stem cells (CSC) act in cancer recurrence, drug-resistance and in metastatic epithelial-to-mesenchymal transition. microRNAs (miRNAs) contribute to cancer is increasing, and miRNA roles in CSC phenotype and fate and their utility as CRC biomarkers have also been reported. Here, we investigated miR-21, miR-221, miR-18a, miR-210, miR-31, miR-34a, miR-10b and miR-16 expression in experimental ALDH+ and CD44+/CD326+ colorectal CSCs obtained from the human CRC cell lines HCT-116, HT-29 and T-84. Then, we moved our analysis in cancer tissue (CT), healthy tissue (HT) and serum (S) of adult CRC patients (n=12), determining relationships with clinical parameters (age, sex, metastasis, biochemical serum markers). Specific miRNA patterns were evident in vitro (normal, monolayers and CSCs) and in patients' samples stratified by TNM stage (LOW vs HIGH) or metastasis (Met vs no-Met). miR-21, miR-210, miR-34a upregulation ad miR-16 dowregulation associated with the CSCs phenotype. miR-31b robustly overexpressed in monolayers and CSCs, and in CT ad S of HIGH grade and Met patients, suggesting a role as marker of CRC progression and metastasis. miR-18a upregulated in all cancer models and associated to CSC phenotype, and to metastasis and age in patients. miR-10b downregulated in CT and S of LOW/HIGH grade and no-Met patients. Our results identify miRNAs useful as colorectal CSC biomarker and that miR-21, miR-210, miR-10b and miR-31b are promising markers of CRC. A specific role of miR-18a as metastatic CRC serum biomarker in adult patients was also highlighted

    Satisfaction with chronic obstructive pulmonary disease treatment: results from a multicenter, observational study

    Get PDF
    Background: Understanding the level of patients' satisfaction with treatment and its determinants have the potential to impact therapeutic management and clinical outcome in chronic conditions such as chronic obstructive pulmonary disease (COPD). Methods: A national, multicenter, longitudinal, observational study of COPD from 20 Italian pulmonary centers to explore patients' satisfaction to treatment [assessed by the Treatment Satisfaction Questionnaire, 9 items (TSQM-9)] and association with clinical parameters [including dyspnea score, COPD Assessment Test (CAT) score, exacerbation rate], adherence to treatment [Morisky Medication-Taking Adherence Scale (MMAS-4)], illness perception [evaluated by Brief Illness Perception Questionnaire (B-IPQ)] in a 1-year follow up. Results: A total of 401 COPD patients were enrolled [69.4% group B Global Initiative for COPD (GOLD), considering 366 patients with available GOLD 2017 classification at enrollment]. At enrollment, satisfaction with treatment was moderate, being TSQM-9 mean scores for effectiveness 64.2 [95% confidence interval (CI) 62.5-65.9], for convenience 75.8 (95% CI 74.2-77.3), and for global satisfaction 65.7 (95% CI 64.0-67.4). Global satisfaction was negatively associated with disease perception (beta = -0.4709, p < 0.0001), and grade of dyspnea (beta = -4.2564, p = 0.009). Satisfaction with treatment was lower in patients with poor compared with optimal adherence to treatment (beta = -4.5608, p = 0.002). Changes in inhalation regimens during follow up did not modify the satisfaction with treatment. Conclusions: The results of this real-life study showed that the patients' satisfaction with treatments is only moderate in COPD. A high grade of patients' satisfaction is associated mainly with a low perception of the disease, high adherence to treatment and lower level of dyspnea

    The Inhibitory Role of miR-486-5p on CSC Phenotype Has Diagnostic and Prognostic Potential in Colorectal Cancer

    Get PDF
    Colorectal cancer (CRC) is the third most frequent cancer worldwide and the second cause of cancer deaths. Increasing evidences supports the idea that the poor prognosis of patients is related to the presence of cancer stem cells (CSCs), a cell population able to drive cancer recurrence and metastasis. The deregulation of microRNAs (miRNAs) plays a role in the formation of CSC. We investigated the role of hsa-miR-486-5p (miR-486-5p) in CRC, CSCs, and metastasis, in order to reach a better understanding of the biomolecular and epigenetic mechanisms mir-486-5p-related. The expression of miR-486-5p was investigated in three di erent matrices from CRC patients and controls and in CSCs obtained from the CRC cell lines HCT-116, HT-29, and T-84. In the human study, miR-486-5p was up-regulated in serum and stool of CRC patients in comparison with healthy controls but down-regulated in tumor tissue when compared with normal mucosa. miR-486-5p was also down-regulated in the sera of metastatic patients. In vitro, miR-486-5p was down-regulated in CSC models and it induced an inhibitory e ect on stem factors and oncogenes in the main pathways of CSCs. Our results provide a step forward in understanding the role of mir-486-5p in CRC and CSC, and suggest that further studies are needed to investigate its diagnostic and prognostic power, possibly in combination with other biomarkers.Instituto de Salud Carlos III PIE16-00045 DTS19/00145Junta de AndalucíaEuropean Union (EU) SOMM17/6109/UGR (UCE-PP2017-3)Chair "Doctors Galera-Requena in cancer stem cell research" CMC-CTS963Fondazione Banco di Sardegn

    KPC-3 Klebsiella pneumoniae ST258 clone infection in postoperative abdominal surgery patients in an intensive care setting: analysis of a case series of 30 patients

    Get PDF
    Objective: We studied the clinical course, Intensive Care Unit (ICU) and hospital outcomes of 30 postoperative abdominal surgery patients who showed severe infections caused by Klebsiella pneumoniae Sequence Type 258 producing K. pneumoniae carbapenemase 3 (KPC-Kp). Methods: Patients with at least two positive blood cultures for KPC-Kp after admission to the ICU were recruited for a 12-month period and treated with a combination regimen of colistin plus tigecycline. They were started on a high-dose (initial dose of 200 mg then 100 q12) of tigecycline combined with colistin, taking into account intra-abdominal abscess severity and MCIs for tigecycline. Results: The average age of the patients was 56.6 ± 15 (male = 16, female = 14), average APACHE score on admission was 22.72. Twenty out of 30 patients (66%) came from the surgical emergency unit. Patients showed KPC-Kp postoperative infection as follows: intra-abdominal abscess in 15 patients (50%), anastomotic leakage in 8 (24%), surgical site infection (SSI) in 4 (12%) and peritonitis in 3 (10%). Overall crude mortality rate in the ICU due to infection was 40% (12 out of 30 patients). Twelve out of 30 patients (40%) were started on a combination treatment of high-dose tigecycline and intravenous colistin; five of them showed tigecycline MICs of 0.8 - 1. Mortality was significantly associated with a greater number of surgical procedures, previous ICU admission (<0.0005), APACHE II ( p=0.018)and SOFA score (p<0.0005) and VAP (0.013). Treatment with high doses of tigecycline obtained a favourable outcome in patients with intraabdominal abscess. Discussion: Critically-ill surgical patients with KPC-Kp infections have to be treated in a timely manner, taking into account the severity of post-operative complications such as intra-abdominal abscess and anastomotic leakage. In these cases, early suspicion and detection are essential to reducing infection-related morbidity and mortality. Finally, studies evaluating antibiotic combination therapy and well-controlled clinical trials are needed to define the optimal treatment of infections caused by KPC-Kp and, more generally, carbapenem-resistant bacteria

    Effect of a single acupuncture treatment on surgical wound healing in dogs: a randomized, single blinded, controlled pilot study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The aim of the study was to investigate the effect of acupuncture on wound healing after soft tissue or orthopaedic surgery in dogs.</p> <p>Methods</p> <p>29 dogs were submitted to soft tissue and/or orthopaedic surgeries. Five dogs had two surgical wounds each, so there were totally 34 wounds in the study. All owners received instructions for post operative care as well as antibiotic and pain treatment. The dogs were randomly assigned to treatment or control groups. Treated dogs received one dry needle acupuncture treatment right after surgery and the control group received no such treatment. A veterinary surgeon that was blinded to the treatment, evaluated the wounds at three and seven days after surgery in regard to oedema (scale 0-3), scabs (yes/no), exudate (yes/no), hematoma (yes/no), dermatitis (yes/no), and aspect of the wound (dry/humid).</p> <p>Results</p> <p>There was no significant difference between the treatment and control groups in the variables evaluated three and seven days after surgery. However, oedema reduced significantly in the group treated with acupuncture at seven days compared to three days after surgery, possibly due the fact that there was more oedema in the treatment group at day three (although this difference was nor significant between groups).</p> <p>Conclusions</p> <p>The use of a single acupuncture treatment right after surgery in dogs did not appear to have any beneficial effects in surgical wound healing.</p

    SNAPSHOT USA 2020: A second coordinated national camera trap survey of the United States during the COVID-19 pandemic

    Get PDF
    Managing wildlife populations in the face of global change requires regular data on the abundance and distribution of wild animals, but acquiring these over appropriate spatial scales in a sustainable way has proven challenging. Here we present the data from Snapshot USA 2020, a second annual national mammal survey of the USA. This project involved 152 scientists setting camera traps in a standardized protocol at 1485 locations across 103 arrays in 43 states for a total of 52,710 trap-nights of survey effort. Most (58) of these arrays were also sampled during the same months (September and October) in 2019, providing a direct comparison of animal populations in 2 years that includes data from both during and before the COVID-19 pandemic. All data were managed by the eMammal system, with all species identifications checked by at least two reviewers. In total, we recorded 117,415 detections of 78 species of wild mammals, 9236 detections of at least 43 species of birds, 15,851 detections of six domestic animals and 23,825 detections of humans or their vehicles. Spatial differences across arrays explained more variation in the relative abundance than temporal variation across years for all 38 species modeled, although there are examples of significant site-level differences among years for many species. Temporal results show how species allocate their time and can be used to study species interactions, including between humans and wildlife. These data provide a snapshot of the mammal community of the USA for 2020 and will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, and the impacts of species interactions on daily activity patterns. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication
    corecore