123 research outputs found

    X-ray absorption near edge structure and Mössbauer spectroscopy in study of iron valence states in tissues

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    X-ray absorption near edge structure Fe K-edge spectra and 57\text{}^{57}Fe Mössbauer spectra of selected standard compounds were recorded at room temperature. Valence and spin states of Fe in these samples known from Mössbauer spectroscopy were correlated with the shapes of X-ray absorption near edge structure spectra in search of possible application of X-ray absorption near edge structure spectroscopy as analytical tool determining local electronic states of iron in tissues. As an example, the X-ray absorption near edge structure spectra of healthy and cancerous tissues of prostate are shown, suggesting Fe3+\text{}^{3+} in cancerous tissues

    Macro-GH - a clinical entity causing a diagnostic challenge - a case report.

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    AIM: Presentation of a new case of a patient with macro-GH, that may interfere with different GH assays leading to false-positive results in serum samples. CASE PRESENTATION: A 61-year-old female was referred with a pituitary macroadenoma and elevated growth hormone levels The laboratory tests showed increased fasting GH level, measured by a sandwich chemiluminescence immunoassay (LIAISON® XL) without suppression on oral glucose tolerance test and normal IGF-1. The patient did not have the typical signs and symptoms of acromegaly. The patient underwent a transsphenoidal resection of a pituitary tumor, showing only α-subunit immunostaining. Postoperative GH levels remained elevated. An interference in the determination of GH level was suspected. GH was analyzed by three different immunoassays, UniCel DxI 600, Cobas e411 and hGH-IRMA. Heterophilic antibodies and rheumatoid factor were not detected in serum sample. GH recovery after precipitation with 25% polyethylene glycol (PEG) was 12%. Size-exclusion chromatography confirmed the presence of macro-GH in serum sample. CONCLUSION: If results of laboratory tests are not consistent with the clinical findings, the presence of an interference within immunochemical assays could be suspected. To identify interference caused by the macro-GH, the PEG method and size-exclusion chromatography should be used

    The basic propositions on defect numbers, root numbers and indices of linear operators

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    Abstract: In this work, we use the notion of the measure of noncompactness in order to establish some results concerning the class of semi-Fredholm and Fredholm operators. Further, we apply the results we obtained to prove the invariance of the Schechter essential spectrum on Banach spaces by means of polynomially compact perturbations

    Application of the high-resolution grazing-emission x-ray fluorescence method for impurities control in semiconductor nanotechnology

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    We report on the application of synchrotron radiation based high-resolution grazing-emission x-ray fluorescence (GEXRF) method to measure low-level impurities on silicon wafers. The presented high-resolution GEXRF technique leads to direct detection limits of about 10¹²  atoms/cm². The latter can be presumably further improved down to 10⁷  atoms/cm² by combining the synchrotron radiation-based GEXRF method with the vapor phase decomposition preconcentration technique. The capability of the high-resolution GEXRF method to perform surface-sensitive elemental mappings with a lateral resolution of several tens of micrometers was probed

    Exact controllability of non-Lipschitz semilinear systems

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    We present sufficient conditions for exact controllability of a semilinear infinite-dimensional dynamical system. The system mild solution is formed by a noncompact semigroup and a nonlinear disturbance that does not need to be Lipschitz continuous. Our main result is based on a fixed point-type application of the Schmidt existence theorem and illustrated by a nonlinear transport partial differential equation
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