The binding characteristics of quinolone antibacterial agent, ofloxacin (OFLX) and ciprofloxacin(CPFX) with catalase(CAT) were studied by fluorescence spectroscopy in aqueous solution. It was showed that both OFLX and CPFX had a strong ability to quench the CAT intrinsic fluorescence through a static quenching procedure. The formation constant K and the number of bind ing site n were further calculated according to the fluorescence quenching r esults.

Objective To investigate the differences of X-ray findings of skeletal fluorosis between coal-burning type endemic fluo-rosis and industrial fluorosis.Methods The patients were randomly selected as research objects including 60 cases of coal-burning type endemic osteofluorosis and 60 cases of industrial osteofluorosis.The X-ray findings on the left forearm,crus and pelvic radio-graphs of these patients were analyzed retrospectively to find out the differences between skeletal fluorosis of coal-burning type endemic fluorosis and industrial fluorosis.Results X-ray features are no significant statistical differences between coal-burning type endemic fluorosis and industrial fluorosis,except these of interosseous membrane ossification of forearm and crus (forearmχ2=10.909,P<0.05;crusχ2=8.547,P<0.05),obturator membrane ossification of pelvis (χ2=36.554,P<0.05),periosteal proliferation outside bone of crus (χ2=4.937,P<0.05),and ossification of soleus (χ2=4.904,P<0.05).Conclusion The X-ray signs of endemic osteofluorosis and industrial skeletal fluorosis are almost similar,but there are some differences between them.