1,226 research outputs found

    Some Results on the Boundary Control of Systems of Conservation Laws

    Full text link
    This note is concerned with the study of the initial boundary value problem for systems of conservation laws from the point of view of control theory, where the initial data is fixed and the boundary data are regarded as control functions. We first consider the problem of controllability at a fixed time for genuinely nonlinear Temple class systems, and present a description of the set of attainable configurations of the corresponding solutions in terms of suitable Oleinik-type estimates. We next present a result concerning the asymptotic stabilization near a constant state for general nĂ—nn\times n systems. Finally we show with an example that in general one cannot achieve exact controllability to a constant state in finite time.Comment: 10 pages, 4 figures, conferenc

    An Efficient Manifold Algorithm for Constructive Interference based Constant Envelope Precoding

    Get PDF
    In this letter, we propose a novel manifold-based algorithm to solve the constant envelope (CE) precoding problem with interference exploitation. For a given power budget, we design the precoded symbols subject to the CE constraints, such that the constructive effect of the multiuser interference is maximized. While the objective function for the original problem is not complex differentiable, we consider the smooth approximation of its real representation, and map it onto a Riemannian manifold. By using the Riemmanian conjugate gradient algorithm, a local minimizer can be efficiently found. The complexity of the algorithm is analytically derived in terms of floating-points operations (flops) per iteration. Simulations show that the proposed algorithm outperforms the conventional methods on both symbol error rate and computational complexity

    A new emerging oral infection: Raoultella planticola in a boy with haematological malignancy

    Get PDF
    BACKGROUND: Oral mucositis is a common complication in pediatric cancer patients, affecting up to 80% of children. Due to neutropenia and disruption of the mucosal barrier, chemotherapy-induced oral mucositis is often complicated by super-infections. CASE REPORT: A 16-years old male with stage 3 Burkitt's lymphoma developed chemotherapy induced oral mucositis grade 3 (according to WHO scale). Ulcers were quickly growing (reaching a maximum diameter of 3 cm) and became greyish in colour, resulting in dysphagia and pain. A swab of the lesions was taken and microbiological tests were performed. The sample grew for Raoultella planticola, an encapsulated Gram-negative bacterium whose full pathogenic potential still needs to be defined. TREATMENT: The patient received antibiotic combination therapy with Amikacin and Ceftazidime for 8 days. Complete healing of the lesions and resolution of the symptoms were reached and he completed his antineoplastic therapy without further complications. FOLLOW-UP: Twelve months after the infection, he is alive and well, with no oral complaints. CONCLUSION: This is the first report of a Raoultella planticola infection in a patient with chemotherapy induced oral mucositis. This type of infection must be added to the list of organisms to be considered when caring for these patients

    Adolescents and primary herpetic gingivostomatitis: an Italian overview

    Get PDF
    Aim The aim of this study was to investigate the therapies administered to Italian adolescents with primary herpetic gingivostomatitis (PHGS) Methods The medical records of 74 adolescents with PHSG were reviewed. The following data were recorded: age, gender, day of onset, type of treatment, lesions' severity, pain scoring, eating, and drinking ability. The oral examination was performed at the first evaluation (T0) and after one week (T1). Results All patients showed up at the first visit at least 48 h after the onset of symptoms. No patient was prescribed an antiviral therapy. An antibiotic therapy was prescribed in order to prevent secondary bacterial infections. Fifteen patients had been treated with non alcoholic chlorhexidine rinses (group A), 29 patients with non alcoholic chlorhexidine rinses plus hyaluronic acid gel (group B); 30 patients with non alcoholic chlorhexidine rinses plus Mucosyte (R) (group C). A significant improvement of the pain scoring and lesions' severity was noted in group C. Conclusion In Italian adolescents, PHGS is diagnosed at least 48 h after onset and the antibiotic therapy is widely prescribed in order to prevent overinfections. Among topical therapies, an association of verbascoside and sodium hyaluronhate seems to favour a faster healing

    Is there any correlation between otitis media and dental malocclusion in children? A systematic review

    Get PDF
    PurposeThis study aims to evaluate whether there is a correlation between otitis and dental malocclusions.MethodsElectronic databases were searched for observational studies published until July 2021 without language or time restrictions. PROSPERO: CRD42021270760. Observational studies on children with and without OM and/or malocclusion were included. After removing duplicates and excluding not-eligible articles, two reviewers screened relevant articles independently. Two reviewers independently extracted data and assessed data quality and validity through the Newcastle-Ottawa Scale (NOS) quality assessment tool for non-randomized studies.ResultsFive studies met the selection inclusion criteria and were included in the studies for a total of 499 patients. Three studies investigated the relationship between malocclusion and otitis media, while the remaining two studies analyzed the inverse relationship and one of them considered eustachian tube dysfunction as a proxy of OM. An association between malocclusion and otitis media and vice versa emerged, although with relevant limitations.ConclusionThere is some evidence that there is an association between otitis and malocclusion; however, it is not yet possible to establish a definitive correlation

    Idiopathic thrombocytopenic purpura: current concepts in pathophysiology and management.

    Get PDF
    Idiopathic thrombocytopenic purpura (ITP) is characterized by a low platelet count, which is the result of both increased pla- telet destruction and insufficient platelet production. Although the development of autoantibodies against platelet glycoproteins remains central in the pathophysiology of ITP, several abnormalities involving the cellular mechanisms of immune modu- lation have been identified. Conventional treatments for ITP aim at reducing platelet destruction, either by immunosuppression or splenectomy. Two new thrombopoietic agents,AMG 531 and eltrombopag, have been used in clinical trials to stimulate platelet production in ITP patients not responsive to standard treatments. These new molecules bear no structural resemblance to thrombopoietin, but still bind and activate the thrombopoietin receptor. This review will focus on the pathophysiology and treatment of ITP in adults, highlighting recent advances in both fields

    Obstetrics and Gynecology Emergency Department Activity during Lockdown in a Teaching Hospital, Hub Center, for COVID-19

    Get PDF
    Background. The lockdown related to the SARS-CoV-2 pandemic has imposed profound changes in the interaction of the population with hospitals and emergency departments. The main aim of this research was to evaluate the impact of lockdown on the activity of obstetrics and gynecology emergency department (OGED) in a teaching hospital, hub center, for COVID-19. Methods. The study considers all visits to the OGED with their different triage color codes that represent the clinical severity of each case (from the most severe to the least one: red, yellow, green, white). Data were selected through the "PSNet"triage program and collected anonymously. We analyzed frequency distributions of the variables separately for each woman and calculated mean and standard deviations for continuous variables. We then analyzed the association between factors and outcomes for categorical variables (expressed as a number and percentage of the total) using the chi-square test (χ2). The level of significance was established with p<0.05. Statistical analysis was performed using SPSS Statistics V20.0. Given the fact that the study has a retrospective observational nature and it is based on an anonymous routine database, approval by the Local Ethics Committee was not necessary. Results. The relative decrease of patients presenting to OGED in 2020 was -50.96%. The percentage of nonpregnant women was significantly lower in 2020 compared to 2019 (p≤0.0001; Δ = -79.46%). Regarding the obstetric group, we saw an important decrease of visits in 2020 compared to 2019 (p<0.0001; Δ = -40%). The prevalence of yellow codes was significantly higher in 2020 (Δ = +29.72%), while that of white (Δ = -61.58%) and green (Δ = -52.22%) codes was significantly lower (p≤0.0001). Comparing the diagnoses at discharge, we could highlight significant reductions in 2020 for more than one diagnosis: bleeding (p≤0.0001; Δ = -70.42%), pain (p≤0.0001; Δ = -81.22%), urinary diseases (p=0.004; Δ = -75.64%), and gastrointestinal diseases (p≤0.0001; Δ = -87.50%). Conclusions. An evident change emerged in relation to the dynamics between the local obstetrical and gynecological population, and OGED resources. The COVID-19 lockdown greatly reduced the rate of admission to OGED without time-related obstetric and gynecological complications. The reduction of admissions suggests a more appropriate use of the ED by patients that may inspire future policies for the implementation of emergency services

    Non-specific oral and cutaneous manifestations of coronavirus disease 2019 in children

    Get PDF
    Background: Coronavirus Disease 2019 (COVID-19) seems to affect children only marginally, as a result, there is less knowledge of its manifestations in childhood. The purpose of this retrospective cross-sectional study was to investigate the oral and cutaneous manifestations in children affected by COVID-19. Material and Methods: All the medical records of children with COVID-19 admitted to the Pediatric Clinic-ASST Spedali Civili of Brescia from March to April 2020 were reviewed. The following data were recorded: Age, temperature, clinical presentation, oral mucosa lesions, taste alteration and cutaneous lesions. Results: The medical records of twenty-seven pediatric patients (mean age 4,2 years + 1,7) were analyzed. The clinical presentation of the disease mainly included elevated body temperature and cough. The following oral lesions were recorded: Oral pseudomembranous candidiasis (7.4 %), geographic tongue (3.7%), coated tongue (7.4 %) and hyperaemic pharynx (37 %). Taste alteration was reported by 3 patients. Six patients presented cutaneous flat papular lesions. Conclusions: As for our paediatric sample, COVID-19 resulted to be associated with non-specific oral and cutaneous manifestations
    • …
    corecore