146 research outputs found

    A novel QR-code based watermarking scheme for digital rights

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    This paper presents a digital rights protection scheme for both colour and grayscale images using a novel approach that combines watermarking and cryptography. The schema involves two parties: the owner of the digital rights and a generic user who acquired some rights on a copy of the image that will be watermarked. The watermark, a QR code derived from a signed “License Agreement”, is repeatedly inserted, and scrambled, by the image right’s owner, into the frequency components of the image, thus producing the watermarked image. The schema, a non-blind type, achieves good perceptive quality and fair robustness using the 3rd level of the Discrete Wavelet Transform. The experimental results show that, inserting more occurrences of a scrambled QR code, the proposed algorithm is quite resistant to JPEG compression, rotation, cropping and salt & peeper noise

    Immunomediated and ischemia-independent inflammation of coronary microvessels in unstable angina.

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    This study investigated whether the myocardium is involved in the acute inflammatory reaction associated with bursts of unstable angina (UA). We looked for the presence of activated DR+ inflammatory cells and the expression patterns, localization, and immunostaining identification of genes for cytokines (IL-1beta, TNF-alpha, IL-6, and IFN-gamma), MCP-1, and iNOS in the left ventricle biopsies from 2-vessel disease anginal patients, 24 with UA and 12 with stable angina (SA), who underwent coronary bypass surgery. Biopsy specimens from 6 patients with mitral stenosis who underwent valve replacement were examined as control hearts (CHs). Plasma levels of IL-2 soluble receptor (sIL-2R) were measured as a marker of systemic immune reaction. In CHs, DR+ cells were undetectable, and cytokine and iNOS mRNA expression were negligible. UA patients had higher sIL-2R levels than SA patients (P<0.01), and their biopsy specimens showed both numerous DR+ cells identified as lymphocytes, macrophages, endothelial cells, and elevated expression levels of cytokine and iNOS genes (from 2.4- to 6.1-fold vs SA; P<0.01). Cytokine and iNOS genes and proteins were localized in endothelial cells without involvement of myocytes. IL-1beta and MCP-1 mRNAs were nearly undetectable. No significant differences were found in the number of DR+ cells, levels of cytokine, and iNOS genes between potentially ischemic and nonischemic left ventricle areas. In SA specimens, DR+ cells were very rare and only mRNAs for TNF-alpha and iNOS genes were overexpressed versus CHs. These results indicated that an acute immunomediated inflammatory reaction, essentially involving coronary microvessels, is demonstrable in UA patients

    Echocardiographic Assessment of Ebstein's Anomaly in a 60-Year-Old Man

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    We present an echocardiographic evaluation of an elderly man affected with Ebstein's anomaly. In the natural history of this congenital disease only 5% of patients survive beyond the fifth decade. The patient presented severe right heart failure and he was refered to our institution for heart transplantation

    Effects of cardioplegic solutions on conductive coronary arteries.

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    The effects of two cardioplegic solutions (CPSs) on isolated, superfused, bovine coronary arteries were compared with those produced by changes in composition of standard Krebs medium. High potassium, low sodium content or the addition of albumin produced vasoconstriction; high magnesium, high glucose content or the addition of mannitol led to vasodilatation. In most cases hypothermia slightly reduced vasoconstriction and enhanced vasodilatation. The action of the two CPSs is the result of the interaction of these basic effects. The results suggest that the vasomotor reactions of coronary arteries to CPS may affect the delivery of the CPS to the myocardium and exert a critical influence on successful cardioplegia
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