9 research outputs found

    Development of the principles of fuzzy rule-based system for hepatocelular carcinoma staging

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    The article proposes the principles for the development of a fuzzy rule-based physician decision support system n to determine the stages of the most common hepatocellular carcinoma (HCC) among malignant tumors of liver. The stages of HCC, i.e., critical situations, are expressed by different combinations of clinical signs of input data and emerging clinical conditions. These combinations shape the multiplicity of possible situations (critical situations) by forming linguistic rules that are in fuzzy relations with one another. The article presents the task of developing a fuzzy rules-based system for HCC staging by classifying the set of possible situations into given classes. In order to solve the problem, fuzzy rules of clinical situations and critical situations deviated from them are developed according to the possible clinical signs of input data. The rules in accordance with the decision-making process are developed in two phases. In the first phase, three input data are developed: nine rules are developed to determine possible clinical conditions based on the number, size, and vascular invasion of tumor. In the second phase, seven rules are developed based on possible combinations of input data on the presence of lymph nodes and metastases in these nine clinical conditions. At this stage, the rules representing the fuzzification of results obtained are also described. The latter provide an interpretation of results and a decision on related stage of HCC. It also proposes a functional scheme of fuzzy rules-based system for HCC staging, and presents the working principle of structural blocks. The fuzzy rule-based system for HCC staging can be used to support physicians to make diagnostic and treatment decision

    Living donor liver transplantation with replacement of vena cava for Echinococcus alveolaris: A case report

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    AbstractINTRODUCTIONThere is no medical treatment for alveolar echinococceal disease (AED) of liver till now. Curative surgical resection is optimal treatment but in most advanced cases curative resection can’t be done. Liver transplantation is accepted treatment option for advanced AED. AED in some case invade surrounding tissue especially inferior vena cava (IVC). Advanced AED with invasion to IVC can be treated with deceased liver transplantation. Although living donor liver transplantation is very difficult to perform in patients with advanced AED with resected IVC, it come into consideration, since there is very few cadaveric liver.PRESENTATION OF CASEHere we present a case with advanced stage of AED of liver which cause portal hypertension and cholestasis. AED invaded surrounding tissue, right diaphragm, both lobes of liver and retrohepatic part of IVC. Invasion of IVC forced us to make resection of IVC and reconstruction with cryopreserved venous graft to reestablish blood flow. After that a living donor liver transplantation was done.DISCUSSIONCurative surgery is the first-choice option in all operable patients with AED of liver. Advanced stage of AED like chronic jaundice, liver abscess, sepsis, repeated attacks of cholangitis, portal hypertension, and Budd-Chiari syndrome may be an indication for liver transplantation. In some advanced stage AED during transplantation replacement of retrohepatic part of IVC could be done with artificial vascular graft, cadaveric aortic and caval vein graft.CONCLUSIONAlthough living donor liver transplantation with replacement of IVC is a very difficult operation, it should be considered in the management of advanced AED of liver with IVC invasion because of the rarity of deceased liver

    Electret composite with deep trapping centers on the interphase boundary

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    An electret composite comprising a polymer matrix material that contains particles of a piezoelectric material with deep trapping centers on the interphase boundaries between the matrix and particles of a piezoelectric material. The piezoelectric material may have a tetragonal or a rhombohedral structure, and the polymer matrix material may be selected from high-density polyethylene, polyvinylidene fluoride, and a copolymer of vinylidenechloride and tetrafluoroethylene. The composite has a potential difference> 500V, lifespan> 10 years, dielectric permeability≧ 20, specific electric resistance≧ 10 14 Ohm· m; provision of deep trapping centers on the interphase boundaries with activation energy in the range of 1 to 1.25 eV, and stable electret charge

    Composites with high photoquenching factor of electroconduction based on polymer-metalorganic compounds

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    A composite material with a high photoquenching factor of electroconductivity comprising a multiple-component system which is a combination of a polymeric material matrix and a ferrocene-type compound contained in the polymeric material matrix. In one or more aspects of the invention, the polymer material matrix may be formed with polypropylene, high-density polyethylene, low-density polyethylene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene fluoride, or a copolymer of vinylidene chloride and trifluoroethylene. Additionally, the ferrocene-type compound may be contained in the composite in an amount of 10 vol. % to 50 vol. % per 100 vol. % of the matrix, an, depending on the type of the polymer used as a matrix and on the content of the ferrocene-type compound in the matrix, the Rf/R0 ratio, where Rf is electrical resistance of the composite under illumination conditions, and R0 is electrical resistance of the composite without illumination, may be increase under illumination with a factor of up to 960

    Hybrid piezoelectric composites with high electromechanical characteristics

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    A hybrid piezoelectric composite comprises a layer of a polymer matrix comprising particles of a PZT group in a micro range of dimensions, which is sandwiched between two layers of a polymer matrix comprising particles of a dielectric material in a nano range of dimensions. The materials of both layers are polarized with electrothermal polarization. The polymer matrices of both component composites may comprise high-density polyethylene, polyvinylidene fluoride, polypropylene, or low-density polyethylene. The dielectric material of the first component nanocomposite may be selected from the group consisting of SiO2 and BaTiO3, and the ceramic particles of the second component are made from a piezoelectric ceramic material of a PZT group having a tetragonal structure
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