647 research outputs found

    In vitro evaluation of carrier based obturation technique: a CBCT study

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    AIM: The goal of the study was to compare the ability of two different carrier based obturation (CBO) techniques to reach working length and fill in three-dimensions root canal systems, by using CBCT. MATERIALS AND METHODS: Twenty-six extracted molars were scanned with CBCT and 40 curved canals were selected (between 30° and 90°) and divided in two similar groups (n=20). All canals were prepared up to size 25 taper .06 using nickel-titanium instrumentation. The canals in the Group SC were obturated using Soft-Core obturators (Kerr, Romulus, Mi, USA), while Group TH canals (n= 20) were obturated using Thermafil Endodontic Obturators (Tulsa Dental Products, Tulsa, OK, USA), strictly following manufacturers' instructions for use. The obturations were analyzed by means of CBCT to measure the distance from the apical limit of obturation to the apical foramen and the presence of voids inside root canals. RESULTS: There was no significant difference between the two groups in the mean distance of the apical extent of the obturation (t test, p>0.05). Overfilling occurred in only 3 cases (2 in Group TH and 1 in Group SC). The percentages of voids in both groups were very low with no significant difference (Z test, p>0.05). CONCLUSIONS: The two tested CBO techniques showed similar positive results in terms of performance, even if, after checking with verifiers, in most cases the size of the selected Soft-Core obturator was one size smaller than Thermafil

    WEUSEDTO—Water End USE Dataset and TOols: An open water end use consumption dataset and data analytics tools

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    Globalization, climate changes, innovative technologies and new human habits have increased atten- tion to water conservation and management. Therefore, behavioural studies became a key element to understand how and when water is used in residential environment. Water End USE Dataset and TOols (WEUSEDTO), an open water end use consumption dataset and data analytics tools, has been released to help researchers, water utilities and companies to test models and algorithms on real water consumption data. The dataset combines with some notebook python able to analyse high-resolution water data (data recorded with 1 sample per second) to provide several tools to manage raw data, compute statistical analysis, learn fixture usage and generate synthetic simulation models. In addition, washbasin flow data were used as a test case to illustrate the main features of WEUSEDTO: providing volume and duration of single events, classifying usages and simulating user’s behaviour

    Design optimization of a high-speed synchronous reluctance machine

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    Synchronous reluctance machines, including the per¬manent magnet assisted variants are competitive motor topologies if the application requires high efficiency and a cost effective solution with a high flux weakening capability. However, increas¬ing operating speeds incur challenging design and development decisions, mainly in order to find design solutions that ensure the machines structural integrity without compromising the overall performance. In this paper, a comprehensive design procedure for high speed synchronous reluctance machines is presented. In order to validate the procedure, a 5 kW, 80000 rpm machine is considered. The proposed strategy consists of a two-step procedure in which the electromagnetic and structural designs have been properly decoupled dividing the design space in two subsets. Each subset mainly affects the electromagnetic or the structural performances. Several structural design optimizations have been then performed with the aim of finding the optimal trade-off between the rotor geometrical complexity (that defines the required computational resources) and the electromagnetic performance. The reported experimental tests of the prototyped machine validate the proposed design strategy which can be used as general guidelines on the structural design of synchronous reluctance machines

    Dynamic control of water distribution system based on network partitioning

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    The availability on the market of remote control valves for water distribution systems allows a more flexible implementation of the “divide and conquer” paradigm, that consists in dividing large networks into smaller district meter areas defining a water network partitioning (WNP), aiming at controlling water balance, pressure levels and water quality protection. The positioning of gate valves is carried out using optimization approaches to guarantee the network reliability that can be significantly reduced by WNP owing to the closure of several pipes by means of gate valves, decreasing topologic and energy redundancy. Anyway, starting from the optimal positioning of remote controlled gate valves, obtained with SWANP software, the paper investigates the effectiveness of dynamic control, in order to face hydraulic failure in fire estinguishment. The proposed methodology, based on heuristic optimization algorithm, finds the optimal layouts minimizing the number of valves to be opened and maximizing the system performance. The study highlights the advantages of adaptively reconfigurable networks starting from a partitioned system, confirming that a dynamic control represents a significant improvement for smart water networks

    Scientific evidence for the treatment of children with irritable bowel syndrome

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    Irritable bowel syndrome (IBS) is the commonest cause of recurrent abdominal pain in children in both more developed and developing parts of the world. It is characterized by abdominal pain that is improved by defecation and whose onset is associated with a change in stool form and/or frequency and is not explained by structural or biochemical abnormalities. A number of potential patho-physiological mechanisms have been described, but so far the exact underlying etiology of IBS is unclear. Likewise, no optimal treatment has ever been found neither for adult nor for pediatric patients. Current therapeutic options include drugs, dietary interventions and biopsychosocial therapies. The present review aims at evaluating the scientific evidence supporting the efficacy of these treatments for children with IBS

    Acute appendicitis in infants

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    Acute appendicitis is very uncommon in the first year of life and often its presentation is atypical with high risk of complications. Hereby, we present 4 clinical cases of infants, who were diag- nosed with acute appendicitis in our hospital over the last year. The reported clinical cases high- light the several drawbacks clinicians face when managing infants with symptoms suggestive for acute appendicitis. After specific diagnostic work-up, even if not conclusive, patients were intra- operatively diagnosed with acute appendicitis and underwent appendicectomy. Maintaining a high index of suspicion for acute appendicitis in infants presenting with intra-abdominal sepsis of unclear etiology is, in our opinion, the most crucial factor to avoid complications and longer hospitalization

    Pyridostigmine in pediatric Intestinal pseudo-obstruction. case report of a 2-year old girl and literature review

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    Pediatric chronic intestinal pseudo-obstruction is a rare disorder characterized by a severe impairment of gastrointestinal motility leading to intestinal obstruction symptoms in the absence of mechanical causes. The diagnosis is usually clinical and diagnostic work is usually aimed to rule out mechanical obstruction and to identify any underlying diseases. Treatment is challenging and requires a multidisciplinary effort. In this manuscript we describe the youngest child successfully treated with the orally administrable, longacting, reversible anti-cholinesterase drug, pyridostigmine. Like other drugs belonging to cholinesterase inhibitors, pyridostigmine enhances gut motility by increasing acetylcholine availability in the enteric nervous system and neuro-muscular junctions. Based on the direct evidence from the reported case, we reviewed the current literature on the use of pyridostigmine in severe pediatric dysmotility focusing on intestinal pseudo-obstruction. The overall data emerged from the few published studies suggest that pyridostigmine is an effective and usually well tolerated therapeutic options for patients with intestinal pseudo-obstruction. More specifically, the main results obtained by pyridostigmine included marked reduction of abdominal distension, reduced need of parenteral nutrition, and improvement of oral feeding. The present case and review on pyridostigmine pave the way for eagerly awaited future randomized controlled studies testing the efficacy of cholinesterase inhibitors in pediatric severe gut dysmotility

    Optimal Sensor Placement in a Partitioned Water Distribution Network for the Water Protection from Contamination

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    Water network protection from accidental and intentional contamination is one of the most critical issues for preserving the citizen health. Recently, some techniques have been proposed in the literature to define the optimal sensor placement. On the other hand, through the definition of permanent DMAs (District Meter Areas), water network partitioning allows significant reduction in the number of exposed users through the full isolation of DMA. In this paper, the optimal sensor placement is coupled with water network partitioning in order to define the best location of isolation valves and control stations, to be closed and installed respectively. The proposed procedure is based on different procedures, and it was tested on a real water network, showing that it is possible both to mitigate the impact of a water contamination and simplify the sensor placement through the water network partitioning

    Celiac crisis as the life-threatening onset of celiac disease in children. a case report

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    Celiac disease (CD) is an immune-mediated enteropathy caused by a permanent sensitivity to gluten in genetically susceptible individuals. In rare cases, CD may occur with a severe potential life-threatening manifestation known as a celiac crisis (CC). This may be a consequence of a delayed diagnosis and expose patients to possible fatal complications. We report the case of a 22-month-old child admitted to our hospital for a CC characterized by weight loss, vomiting, and diarrhea associated with a malnutrition state. Early identification of symptoms of CC is essential to provide a prompt diagnosis and management

    High speed drives review: machines, converters and applications

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    The development of new power electronic device and high performance magnetic materials are the main technological factors that have led both industries and research community to focus their attention on high speed electrical drives. Several papers have already outlined the electrical machine and/or converter topology choice for certain high speed application. This choice depends on the applications under study. This paper aims to identify the most important high speed applications. For each of them, the main design challenges are highlighted and an overview of available market product is presented
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