ABSTRACT
Objective To compare two exposure modes on image quality and radiation dose when used for double lower extremities full-length photography so as to provide guidance for clinical application. Methods Totally 60 patients undergoing double lower extremities full-length photography were selected with sequential experiment and then divided into two groups randomly and equally,of whom,there were four ones with genu varum.In the two groups,one group applied the exposure mode of AEC,and the other involved in FIXED mode.Then the two groups were compared on image quality and radiation dose. Results The exposure radiation to the patient under FIXED mode was higher than that under AEC mode although the common patients had the image quality with no significant difference in the two groups, and FIXED mode resulted in higher image quality for the patients with genu varum than AEC mode.Conclusion Exposure modes have effects on image quality and exposure dose,and it's suggested that AEC mode be applied for common patients from the aspect of radiation protection while FIXED mode be used for the patients with genu varum. [Chinese Medical Equipment Journal, 2018,39(5):68-70,74]
ABSTRACT
The chemical structure, biological activity, biosynthesis and application of metabolites of Myxococcus published in literature are summarized in this paper. Emphasis is laid on the actin-binding macrolide rhizopodin, the respiratory chain inhibitors peptide myxothiazol and polyenoid myxalamid, the aromatic compound myxopyronin and saframycin Mx1 acting on nucleic acid, and the macrocyclic compound myxovirescin interfering with cell wall. This review clarifies the diversity of the chemical structure and biological activity of the secondary metabolites of Myxococcus, and provides some clues for the development of their bioactive natural products.