340 research outputs found

    Partially Coherent Vortex Beam: From Theory to Experiment

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    Partially coherent vortex beam exhibits some unique and interesting properties, for example, correlation singularities (i.e., ring dislocations) exist in its correlation function, and one can determine the magnitude of the topological charge of the vortex phase from the number of the ring dislocations. Modulating the coherence of a vortex beam provides a convenient way for shaping its focused beam spot, which is useful for material processing and optical trapping. Furthermore, a partially coherent vortex beam has an advantage over a partially coherent beam without vortex phase for reducing turbulence‐induced scintillation, which will be useful in free‐space optical communications. We introduce recent theoretical and experimental developments on partially coherent vortex beams

    Fluorescence quenching and measurement of captopril in pharmaceuticals

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    The mechanism of fluorescence quenching of the product S in the presence of captopril was studied. The maximum emission wavelength of the product S was at 405 nm with the excitation wavelength at 316 nm. It was found that the fluorescence quenching of product S was of a static one and the binding constant (K) was 9.29 × 106 J mol-1. A linear relationship was found between the relative fluorescence intensity of the product S-captopril system and the concentration of captopril. Under optimum conditions, the linear range of the calibration curve for captopril was 2~160 μg L-1 with a correlation coefficient of 0.9926 and a detection limit of 0.1 μg L-1. The relative standard deviation (RSD) was 3.60%. The analytical results of the pharmaceuticals obtained by this novel method agreed quite well with those obtained by the KIO3 titrimetry

    Fluorescence quenching and measurement of captopril in pharmaceuticals

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    270-276The mechanism of fluorescence quenching of the product S in the presence of captopril was studied. The maximum emission wavelength of the product S was at 405 nm with the excitation wavelength at 316 nm. It was found that the fluorescence quenching of product S was of a static one and the binding constant (K) was 9.29 × 106 J mol-1. A linear relationship was found between the relative fluorescence intensity of the product S-captopril system and the concentration of captopril. Under optimum conditions, the linear range of the calibration curve for captopril was 2~160 μg L-1 with a correlation coefficient of 0.9926 and a detection limit of 0.1 μg L-1. The relative standard deviation (RSD) was 3.60%. The analytical results of the pharmaceuticals obtained by this novel method agreed quite well with those obtained by the KIO3 titrimetry

    Aberrant expression of decoy receptor 3 in human breast cancer: relevance to lymphangiogenesis

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    AbstractBackgroundDecoy receptor 3 (DcR3), a decoy receptor against Fas ligand belonging to the tumor necrosis factor receptor superfamily, is overexpressed in some forms of cancer. It was recently reported that DcR3 could protect endothelial cells from apoptosis, implying a potential role in the development of vessels, whereas its role in the lymphangiogenesis remains unclear. In the present study, we studied the DcR3 expression and its relationship with the lymphatic microvessel density (LMVD) to investigate if it played a role in the lymph metastasis of human breast cancer.Materials and methodsReal-time polymerase chain reaction and immunohistochemistry were performed to measure the messenger RNA and protein expression of DcR3 in the breast cancer tissues, noncancerous counterparts, and axillary lymph node from 63 patients. LMVD in these specimens was assessed by counting the D2-40 labeled–microvessels. Furthermore, the correlations between DcR3 expression and LMVD and other clinicopathologic parameters were analyzed.ResultsDcR3 was overexpressed in the breast cancer tissue of 58 patients (92.1%) and was also expressed in vascular endothelial cells and tumor cells in the lymph nodes. LMVD in cancer tissue and lymph nodes were both positively correlated to the aberrant expression of DcR3.ConclusionsThe relevance between DcR3 overexpression and LMVD revealed the existence of possible links between DcR3 and lymphangiogenesis. Based on these findings, it is important to further explore the regulation of lymphangiogenesis operated by the reverse tumor necrosis factor signaling of DcR3
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