1,065 research outputs found

    A Semi-Markov Modulated Interest Rate Model

    Full text link
    In this paper we propose a semi-Markov modulated model of interest rates. We assume that the switching process is a semi-Markov process with finite state space E and the modulated process is a diffusive process. We derive recursive equations for the higher order moments of the discount factor and we describe a Monte Carlo al- gorithm to execute simulations. The results are specialized to classical models as those by Vasicek, Hull and White and CIR with a semi-Markov modulation

    Recovery and sanitary selection of local vines of the Sardinia

    Get PDF
    A study was made on the recovery genotypes local grapevine with the aim to conserve them and to evaluate their health status and thus to improve the quality of the propagation material. Clone accessions of 61 vines were grafted and placed in a germoplasma field. The varieties that were considered enologically valuable were subjected to sanitary selection. Some vines showed indubitable healthy qualities, and should be immediately evaluated from an economical point view and then certificated. Possible sanitation treatments were also evaluated, with the aim of extending the number clone accessions to be included in experimental trials to access their yield

    Hepatitis B virus and hepatitis C virus co-infection: additive players in chronic liver disease?

    Get PDF
    Hepatitis B virus (HBV) and hepatitis C virus (HCV) share modes of transmission and their combined infection is a fairly frequent occurrence particularly in areas where the two viruses are endemic and among subjects with a high risk of parenteral infections. Moreover, the number of coinfected patients is likely higher than is usually thought. In fact, many studies have shown that HBV genomes may also be present in HBsAg-negative patients, particularly in those with HCVrelated chronic hepatitis. This condition is commonly called "occult HBV infection". Much evidence suggests that coinfection by HBV and HCV may have considerable clinical relevance. In particular, this condition is generally believed to be a factor favouring the progression of liver fibrosis toward cirrhosis and the development of liver cancer, and in case of both overt and occult HBV infection. In spite of its potential clinical impact, however, there is few information about the possible interplay between the two viruses. Here, we concisely reviewed the available data on the virological and clinical features of the dual HBV/HCV infection prospecting the aspects that should be highlighted in the nearest future for improving the knowledge on this important field of the hepatology

    Therapy of Occult Hepatitis B Virus Infection and Prevention of Reactivation

    Get PDF
    Occult hepatitis B virus infection (OBI) is highly prevalent worldwide. In some cases, it is a consequence of infection with variant viruses mutated in the S gene and producing a surface antigen not recognized by diagnostic kits. In most cases, OBI is due to a strong inhibition of hepatitis B virus (HBV) activities exerted by host defense mechanisms. OBI may reactivate in patients undergoing immunosuppressive therapy and/or chemotherapy with the possibility of a consequent development of acute hepatitis that may lead to hepatic failure. Hematological malignancies and therapeutic schedules including rituximab are the conditions most frequently associated with OBI reactivation. However, this event may occur in a large number of additional clinical and therapeutic settings. Identification of patients prone to undergo reactivation is of great importance for promptly starting a proper antiviral therapy that may stop the HBV reactivation and prevent its clinical sequelae

    Effect of off-pump coronary surgery with right ventricular assist device on organ function and inflammatory response: a randomized controlled trial.

    No full text
    BACKGROUND: Right ventricular assist devices (RVADs) have been proposed to improve exposure of the coronary arteries in off-pump surgery. In this study we investigated the impact of the A-Med RVAD on inflammatory response and organ function in patients undergoing coronary artery bypass grafting. METHODS: Sixty patients were prospectively randomized to conventional surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest, beating heart surgery (off-pump), or beating heart surgery with the RVAD. Serial blood samples were collected postoperatively, for analysis of inflammatory markers, troponin I, protein S100, and free hemoglobin. Renal tubular function was assessed by measuring urine N-acetyl-glucosaminidase activity. RESULTS: No hospital deaths or major postoperative complications occurred in the study population. Interleukin-6, interleukin-8, C3a, and troponin I levels after surgery were significantly higher in the CPB group compared with the off-pump and RVAD groups. Free hemoglobin levels immediately after the operation, peak and total S100 levels, and N-acetyl-glucosaminidase activity were also significantly higher in the CPB group. CONCLUSIONS: Off-pump coronary revascularization, with or without RVAD, reduces inflammatory response, myocardial, neurologic, and renal injury, and decreases hemolysis when compared with conventional surgery with CPB and cardioplegic arrest

    Oxidative dearomatization of phenols and polycyclic aromatics with hydrogen peroxide triggered by heterogeneous sulfonic acids

    Get PDF
    Suitable heterogeneous sulfonic acid derivatives ensure the smooth dearomatization of phenols and bare naphthalenes under mild conditions. The method uses hydrogen peroxide which is a clean oxidant, offering a convenient metal-free tool to access families of quinones derivatives in good yields and with low catalyst loading

    Effectiveness of add-on Pegylated interferon alfa-2a therapy in a Lamivudine-treated patient with chronic hepatitis B

    Get PDF
    Hepatitis B virus (HBV) surface antigen (HBsAg) to anti-HBsAg (anti-HBs) antibody seroconversion is the best, final objective for all available chronic hepatitis B (CHB) treatments. Unfortunately, this goal is rarely obtained with the currently utilized therapeutic approaches. Here we describe the case of a CHB patient who was very successfully treated with a particular therapeutic schedule. The patient was initially treated with lamivudine for four years. Subsequently, pegylated interferon alpha-2a was introduced for a period of one year. During this period of combined therapies, the patient showed a flare of aminotransferase values followed by complete normalization of liver biochemistry parameters and HBsAg/anti-HBs seroconversion that persisted up to 24 months after all therapies had been stopped
    corecore