2,016 research outputs found

    2-(5-Amino-2H-tetra­zol-2-yl)acetic acid

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    In the title mol­ecule, C3H5N5O2, the tetra­zole ring and carboxyl group form a dihedral angle of 82.25 (14)°. In the crystal, adjacent mol­ecules are linked through O—H⋯N, N—H⋯O and N—H⋯N hydrogen bonds into layers parallel to the bc plane

    Content-Aware Quantization Index Modulation:Leveraging Data Statistics for Enhanced Image Watermarking

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    Image watermarking techniques have continuously evolved to address new challenges and incorporate advanced features. The advent of data-driven approaches has enabled the processing and analysis of large volumes of data, extracting valuable insights and patterns. In this paper, we propose two content-aware quantization index modulation (QIM) algorithms: Content-Aware QIM (CA-QIM) and Content-Aware Minimum Distortion QIM (CAMD-QIM). These algorithms aim to improve the embedding distortion of QIM-based watermarking schemes by considering the statistics of the cover signal vectors and messages. CA-QIM introduces a canonical labeling approach, where the closest coset to each cover vector is determined during the embedding process. An adjacency matrix is constructed to capture the relationships between the cover vectors and messages. CAMD-QIM extends the concept of minimum distortion (MD) principle to content-aware QIM. Instead of quantizing the carriers to lattice points, CAMD-QIM quantizes them to close points in the correct decoding region. Canonical labeling is also employed in CAMD-QIM to enhance its performance. Simulation results demonstrate the effectiveness of CA-QIM and CAMD-QIM in reducing embedding distortion compared to traditional QIM. The combination of canonical labeling and the minimum distortion principle proves to be powerful, minimizing the need for changes to most cover vectors/carriers. These content-aware QIM algorithms provide improved performance and robustness for watermarking applications.Comment: 12 pages, 10 figure

    Autoimmune Response Confers Decreased Cardiac Function in Patients with Rheumatic Mitral Lesion following Valve Replacement

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    Purpose: To explore the effect of autoimmune response on the decreased cardiac function in patients with rheumatic mitral lesion following valve replacement.Methods: In this case-controlled study, 29 patients who had undergone valve replacement as a result of mitral lesion were enrolled (mean age = 48.7 years). Twenty healthy volunteers were selected as control (mean age = 47.5 years). Plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high –sensitivity C-reactive protein (hs-CRP) and echocardiographic indices of heart function in the two groups were investigated, respectively. Body mass index (BMI) was also calculated.Results: TNF-α, IL-6 and hs-CRP levels in plasma were significantly higher than those in controls (p < 0.05; 22.23 pg/mL vs. 13.24 pg/mL, 53.42 pg/mL vs. 9.57 pg/mL, and 2.12 ÎŒg/mL vs. 0.97 ÎŒg/mL, respectively). The indices of left atrial diameter (LAD), left ventricular end-diastolic diameter (LDD) and isovolumetric contraction time (ICT) were significantly higher (p < 0.05; 4.72 cm vs. 3.78 cm, 4.85 cm vs. 4.37 cm, and 76.38 ms vs. 66.24 ms, respectively), but those of early diastolic velocity (Ea), late diastolic velocities (Aa) and ejection time (ET) were significantly lower (p < 0.05; 7.65 cm/s vs. 16.8 cm/s, 5.56 cm/s vs. 12.9 cm/s, and 261.54 ms vs. 276.14 ms, respectively). Two-dimensional echocardiography obtained the same results.Conclusion: Valve replacement in patients with rheumatic heart disease (RHD) does not attenuate inflammatory response; rather, autoimmune response would keep affecting decreased heart function in RHD patients who have received mitral valve replacement.Keywords: Tumor necrosis factor-α, Interleukin-6, High sensitivity C reactive protein, Mitral lesion, Mitral valve replacemen

    6-Hydroximino-4-Aza-A-Homo-Cholest-3-One and Related Analogue as A Potent Inducer of Apoptosis in Cancer Cells

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    Here we report that 6-hydroximino-4-aza-A-homo-cholest-3-one and 6-hydroxyl-4-aza-A-homo-cholest-3-one, new steroidal lactams were synthesized recently, displayed antiproliferative activity against some cancer cells through inducing cancer cell apoptosis by activation of the intrinsic pathway. The apoptotic function of the compounds was demonstrated by release of cytochrome C, activation of caspase 3 and annexin V labeling. Furthermore, the compound was able to inhibit tumor growth in an athymic mouse model

    Local geometry and quantum geometric tensor of mixed states

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    The quantum geometric tensor (QGT) is a fundamental concept for characterizing the local geometry of quantum states. After casting the geometry of pure quantum states and extracting the QGT, we generalize the geometry to mixed quantum states via the density matrix and its purification. The gauge-invariant QGT of mixed states is derived, whose real and imaginary parts are the Bures metric and the Uhlmann form, respectively. In contrast to the imaginary part of the pure-state QGT that is proportional to the Berry curvature, the Uhlmann form vanishes identically for ordinary physical processes. Moreover, there exists a Pythagorean-like equation that links different local distances and reflect the underlying fibration. The Bures metric reduces to the Fubini-Study metric as temperature approaches zero if the eigenvalues of the density matrix do not change during the process, establishing a correspondence between pure and mixed states. We also present two examples with contrasting local geometries and discuss experimental implications.Comment: 22 pages, 3 figure
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