165 research outputs found

    Evaluation of the single jet flow rate for a multi-hole GDI nozzle

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    Fuel injectors featuring differentiated hole-to-hole dimensions improve the fuel distribution in the cylinder ensuring a more efficient and cleaner combustion for GDI (Gasoline Direct Injection) engines. A proper diagnostic system able to detect the actual fuel flow rate exiting each hole of a GDI nozzle is requested in order to optimize the matching between the spray and the combustion chamber. Measuring the spray impact force of a single plume allows the detection of the momentum flux exiting the single hole and, under appropriate hypotheses, the evaluation of the corresponding mass flow rate time-profile. In this paper two methodologies for the hole-specific flow rate evaluation, both based on the spray momentum technique, were applied to two different GDI nozzles, one featuring equal hole dimensions and one with two larger holes. Three different energizing times at 100 bar of fuel pressure were tested in order to cover a wide range of operating conditions. The results were validated in terms of injected mass by means of a proper device able to collect and weigh the fuel injected by each single nozzle hole, and in terms of mass flow rate using a Zeuch-method flow meter as reference. Both the proposed methodologies showed an excellent accuracy in the fuel amount detection with percentage error lower than 5% for standard energizing times and lower than 10% for very short injections working in ballistic conditions. The mass flow rate time-profile proved a good accuracy in the detection of the start and end of injection and the static flow rate level

    Determinants of enhanced thromboxane biosynthesis in renal transplantation

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    Background. Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients (RTRs) are still significant, with a high incidence of cardiovascular disease-related deaths. Methods. We investigated thromboxane (TXA2) biosynthesis and endothelial and coagulative activation in 65 patients who received a renal transplant. Results. The rate of TXA2 biosynthesis (urinary 11-dehydro-TXB2 excretion largely reflects platelet TXA2 production in vivo) was significantly (P < 0.0001) higher in RTRs than in healthy subjects. Plasma von Willebrand factor (vWF) and thrombin-antithrombin (TAT) complexes were significantly higher (P < 0.001) in RTRs compared with controls. Urinary 11-dehydro-TXB2 directly correlated with plasma vWF and cholesterol. We next examined the relative influence of cyclosporine A (CsA) on TXA2 biosynthesis and endothelial activation, comparing a group of RTRs not receiving CsA with an age- and sex-matched group of patients treated with CsA. Urinary excretion of 11-dehydro-TXB2 and plasma levels of vWF were significantly increased in RTRs who received CsA compared with those who did not. After an overall follow-up of 120 months, RTRs who experienced cardiovascular events had a higher frequency of abnormal plasma levels of vWF than patients who remained event free. Conclusion. Renal transplantation is associated with in vivo platelet activation highly related to endothelial activation. This is particularly evident in CsA-treated patients. Administration of drugs that are able to reduce or eliminate thromboxane-dependent platelet activation in vivo may be beneficial to reduce the risk of cardiovascular events in RTRs

    Prodromal phase: Differences in prodromal symptoms, risk factors and markers of vulnerability in first episode mania versus first episode psychosis with onset in late adolescence or adulthood

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    Objective: This study was aimed at identifying differences in the prodromal symptoms and their duration, risk factors and markers of vulnerability in patients presenting a first episode mania (FEM) or psychosis (FEP) with onset in late adolescence or adulthood in order to guide tailored treatment strategies. Methods: Patients with a FEM or FEP underwent a clinical assessment. Prodromes were evaluated with the Bipolar Prodrome Symptom Scale-Retrospective (BPSS-R). Chi-squared tests were conducted to assess specific prodromal symptoms, risk factors or markers of vulnerability between groups. Significant prodromal symptoms were entered in a stepwise forward logistic regression model. The probabilities of a gradual versus rapid onset pattern of the prodromes were computed with logistic regression models. Results: The total sample included 108 patients (FEM = 72, FEP = 36). Social isolation was associated with the prodromal stage of a FEP whilst Increased energy or goal-directed activity with the prodrome to a FEM. Physically slowed down presented the most gradual onset whilst Increased energy presented the most rapid. The presence of obstetric complications and difficulties in writing and reading during childhood were risk factors for FEP. As for markers of vulnerability, impairment in premorbid adjustment was characteristic of FEP patients. No specific risk factor or marker of vulnerability was identified for FEM. Conclusion: Early characteristics differentiating FEP from FEM were identified. These findings might help shape early identification and preventive intervention programmes

    Personalizing Cancer Pain Therapy: Insights from the Rational Use of Analgesics (RUA) Group

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    Introduction: A previous Delphi survey from the Rational Use of Analgesics (RUA) project involving Italian palliative care specialists revealed some discrepancies between current guidelines and clinical practice with a lack of consensus on items regarding the use of strong opioids in treating cancer pain. Those results represented the basis for a new Delphi study addressing a better approach to pain treatment in patients with cancer. Methods: The study consisted of a two-round multidisciplinary Delphi study. Specialists rated their agreement with a set of 17 statements using a 5-point Likert scale (0 = totally disagree and 4 = totally agree). Consensus on a statement was achieved if the median consensus score (MCS) (expressed as value at which at least 50% of participants agreed) was at least 4 and the interquartile range (IQR) was 3–4. Results: This survey included input from 186 palliative care specialists representing all Italian territory. Consensus was reached on seven statements. More than 70% of participants agreed with the use of low dose of strong opioids in moderate pain treatment and valued transdermal route as an effective option when the oral route is not available. There was strong consensus on the importance of knowing opioid pharmacokinetics for therapy personalization and on identifying immediate-release opioids as key for tailoring therapy to patients’ needs. Limited agreement was reached on items regarding breakthrough pain and the management of opioid-induced bowel dysfunction. Conclusion: These findings may assist clinicians in applying clinical evidence to routine care settings and call for a reappraisal of current pain treatment recommendations with the final aim of optimizing the clinical use of strong opioids in patients with cancer

    Narrative Spaces: bridging architecture and entertainment via interactive technology

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    Our society's modalities of communication are rapidly changing. Large panel displays and screens are be ing installed in many public spaces, ranging from open plazas, to shopping malls, to private houses, to theater stages, classrooms, and museums. In parallel, wearable computers are transforming our technological landscape by reshaping the heavy, bulky desktop computer into a light weight, portable device that is accessible to people at any time. Computation and sensing are moving from computers and devices into the environment itself. The space around us is instrumented with sensors and displays, and it tends to reflect adiffused need to combine together the information space with our physical space. This combination of large public and miniature personal digital displays together with distributed computing and sensing intelligence offers unprecedented opportunities to merge the virtual and the real, the information landscape of the Internet with the urban landscape of the city, to transform digital animated media in story tellers, in public installations and through personal wearable technology. This paper describes technological platforms built at the MIT Media Lab, through 1994-2002, that contribute to defining new trends in architecture that merge virtual and real spaces, and are reshaping the way we live and experience the museum, the house, the theater, and the modern city
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