508 research outputs found

    Role of antiviral therapy in the natural history of hepatitis B virus-related chronic liver disease

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    Hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, hepatocytes, and the host immune system. Natural history studies of chronic hepatitis B (CHB) infection have shown an association between active viral replication and adverse clinical outcomes such as cirrhosis and hepatocellular carcinoma. The goal of therapy for CHB is to improve quality of life and survival by preventing progression of the disease to cirrhosis, decompensation, end-stage liver disease, hepatocellular carcinoma (HCC) and death. This goal can be achieved if HBV replication is suppressed in a sustained manner. The accompanying reduction in histological activity of CHB lessens the risk of cirrhosis and of HCC, particularly in non-cirrhotic patients. However, CHB infection cannot be completely eradicated, due to the persistence of covalently closed circular DNA in the nucleus of infected hepatocytes, which may explain HBV reactivation. Moreover, the integration of the HBV genome into the host genome may favour oncogenesis, development of HCC and may also contribute to HBV reactivation

    Insights on Funeral Practices and Insects Associated with the Tombs of King Ferrante II d'Aragona and Other Renaissance Nobles

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    The impressive Sacristy of the Basilica of San Domenico Maggiore contains 38 wooden sarcophagi with the bodies of 10 Aragonese princes and other Neapolitan nobles, who died in the 15th and 16th centuries. To improve the knowledge about the entomofauna associated with bodies in archaeological contexts, herein we provide insights on the funerary practices and the insect community associated to Ferrante II King of Naples and other Italian Renaissance mummies of the Aragonese dynasty buried in the Basilica of St. Domenico Maggiore. We identified 842 insect specimens: 88% were Diptera (Muscidae, Fanniidae, and Phoridae), followed by 9% Lepidoptera (Tineidae) and 3% Coleoptera (Dermestidae and Ptinidae). Ninety-seven percent of the specimens were collected from the coffin of Francesco Ferdinando d'Avalos, which was the best preserved. A lack of fly species characterizing the first colonization waves of exposed bodies was noted. The most common fly was the later colonizing muscid Hydrotaea capensis (Wiedemann); only a few Fanniidae (Fannia spp.) were retrieved. The lack of blowflies, coupled with recording H. capensis as the dominant fly, supports our hypothesis that corpses have been kept indoors for a long time under confined environmental conditions. Other explanations include odorous oils/balms having been used in the embalming process, causing the delay or stopping the arrival of first colonizer flies. Hermetically sealing of the coffin with bitumen may also have played a role in preventing access to the corpses. This scenario describes a historical context characterized by a well-advanced knowledge of body preparation, with specific burial techniques adopted for nobles

    The influence of antioxidants and cycloheximide on the level of nitric oxide in the livers of mice in vivo

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    AbstractWhen injected into mice prior to the NO generation increase induced with lipopolysaccharide (LPS) from Escherichia coli, exogenous antioxidants diethyldithiocarbamate (DETC) or phenazan (sodium 3.5-di-tert-butyl-4-oxiphenylpropionate) as well as the inhibitor of protein biosynthesis, cycloheximide (CHI) attenuated the NO production in mouse liver in vivo. These data demonstrated the key role of free radicals, which were likely, active oxygen species, in the synthesis of inducible NO-synthase (iNOS) responsible for the NO production in this organ. Similar effects of phenazan and CHI were observed in livers of mice treated with γ-irradiation or LPS + Fe2+-citrate, which suggested that these treatments also induced 1NOS synthesis through initiating the action of active oxygen species. The rate of NO synthesis was estimated by accumulation of paramagnetic mononitrosyl iron complexes with DETC (MNIC-DETC) detected using the EPR method. The formation of MNIC-DETC complexes was found in the brain of mice pre-treated with LPS + Fe2+-citrate which seemed to be due to iNOS synthesis stimulated by this treatment

    Creation of Structural Polymer Composite Materials for Functional Application Using Physicochemical Modification

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    The various aspects of physico-chemical modification of the components of structural materials of functional application based on classical composites and nanocomposites are analyzed. Potential applications of such materials are briefly described. Ultrasonic cavitation treatment is considered as a basic method of physical modification when obtaining the indicated classes of composites. The influence of ultrasonic treatment modes on the technological and operational properties of reactoplastic polymers, as well as on the hardening of reinforced composites based on them, is investigated. Technical means of ultrasonic cavitation processing of liquid binders and polymer composites based on them are briefly described. An effective spectrum of interrelated structural and technological parameters of ultrasonic treatment has been characterized, which is established by calculation and experimentally-statistically. The design issues of the technological processes of obtaining polymer composites of functional application are analyzed. The efficiency of creating carbon fiber composite materials, as well as the prospects for creating of these materials based on reinforcing fabric with nanomodified fillers is described. The methods of obtaining functional nanomodified carbon-composites with improved physicomechanical and operational properties, in particular with increased strength and electrical conductivity, are characterized. The effectiveness of the ultrasonic treatment and production of nanomodified thermoplastic composite materials by extrusion method is considered. Some issues of forming products from intelligent polymer composites are analyzed. The results of the survey can be used in the design of advanced technologies for the creation of functional polymer composites of functional application

    Use of Physicochemical Modification Methods for Producing Traditional and Nanomodified Polymeric Composites with Improved Operational Properties

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    Various aspects of the methods of physical and physicochemical modification of components of filled thermo-plastic composite materials are analyzed, aimed at improving the surface properties of the fillers and the technological properties of the polymer matrix during their interaction. It is noted that the improvement of the interfacial interaction of the components of polymer reactoplastic composites, including adhesive strength, is a key factor for improving the reliability of the cured filled composite. As a promising area of research, a modification of the surface of the reinforcing fibrous filler and the technological characteristics of the liquid polymer binder, aimed at increasing their contact properties in the composite was chosen. The effectiveness of the physical method of modifying the components of composites in the form of low-frequency ultrasonic processing is described. The peculiarities of cluster formation and physicochemical modification of epoxy polymers filled with dispersed fillers are analyzed. Attention is focused on the effectiveness of ultrasonic processing in cavitation mode for deagglomeration and uniform distribution of nanoparticles in a liquid medium during the creation of nanocomposites. Experimentally confirmed the improvement of the technological properties of liquid epoxy polymers, modified by ultrasound, used for the impregnation of oriented fibrous fillers, as well as the improvement of the physicomechanical properties of the sonicated epoxy matrices
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