Assessment of parameters of digital X-ray detectors using the method of exposure of the working area of the detector to uniform X-ray radiation
It is shown that the main parameters determining the imaging quality of digital X-ray image detectors can be assessed by the method of exposure of the working area of the detector to uniform X-ray radiation. This method makes unnecessary the expert evaluation and measurements using high-precision test objects. It can be used in clinical practice for effective monitoring of the quality of digital X-ray detectors.
Modulation Transfer Function of Radiographic Systems Using Fluorescent Screens
When radiographic film is exposed with fluorescent intensifying screens, the spatial x-ray quantum fluctuations are recorded on the film in the form of density fluctuations (“quantum mottle”). The x-ray quantum fluctuations can be regarded as the input and the quantum mottle as the output of the image-forming system. The Wiener spectrum of the quantum mottle has been used to determine the relative modulation transfer function of two radiographic systems.
Chemical constituents and chemotaxonomic study of Glycyrrhiza pallidiflora maxim
Abstract Phytochemical study of Glycyrrhiza pallidiflora Maxim. gave seventeen compounds, including two sterols (3 and 4), four triterpenes (1, 2, 5, 6), ten flavones (7, 9–17), and one pterocarpan (8). The chemotaxonomic significance of G. pallidiflora was discussed, which indicated the close relationship between G. pallidiflora with other species of Glycyrrhiza. Moreover, pallidiflorin can be served as a fingerprint for G. pallidiflora, macedonic acid and echinatin can be recognized as biomarkers for Glycyrrhiza, while formononetin, afrormosin and calycosin may be typical second metabolites for Papilionoideae.