ABSTRACT
Objective To know the microcystins pollution caused by cyanobactcria bloom in two drinking water sources in Ningbo city.Methods Water samples were collected at four sampling sites in Yaojiang River and three sampling sites in Miehu reservoir from 20 July,2007 to 31 August,2007.The algae in these water samples were classified and counted,and Microcystin-LR (MC-LR),MC-RR were determined by UPLC-MS-MS.Results The Cyanobacteria cell concentration in Yaojiang River and Meihu reservoir ranged from 0.8?10~6 to 6.7?10~7,and from 1.21?10~7 to 9.928?10~8 cells/L respectively.The MC-LR and MC-RR in Yaojiang River weren't detected,and neither was the MC-RR in MeiHu reservoir.However,the MC-LR was detected at sometimes,and the maximum concentration of MC-LR was 0.84?g/L.Conclusion There is no microcystins pollution in Yaojiang River,but there existed MC-LR pollution in MeiHu Reservoir,and the MC-LR concentration in it was below national standard limit of 1.0?g/L after the treatment of controlling alage and microsystins.
ABSTRACT
Objective To evaluate the diagnostic advantage of the ratio of ligamentum flavum(LF) thickness to oblique canal diameter(TODR)measured on CT images in patients with lumbar canal stenosis. Methods Seventy-one patients underwent CT and MRI examinations respectively,and they were divided into two groups,the positive group and negative group,according to the presence or absence of dural sac notch caused by the LF on bilateral parasagittal MR images.Meanwhile,50 volunteers without any symptom in the lumbar region or legs were examined by CT.TODRs were measured at the L3—S1 levels of the inferior margin of the intervertebral disc on transverse CT images,respectively.The results were further analyzed with the positive findings on MR images,clinical symptoms and physical examination,so as to find out the statistical correlation between them.Results LF thickness was(3.01?0.72)mm and TODR was 0.19?0.04 in the negative group,(3.94?0.84)mm and 0.28+0.06 in the positive group,and(3.16? 0.85)mm and 0.19?0.04 in the control group.There was significant difference between positive group and negative group or control group for LF thickness(P0.24, the sensitivity,specificity and positive predictive value were 74.8%,89.6% and 73.6% respectively. Positive correlation existed between LF thickness or TODR and clinical symptom(r=0.72,0.86,P