This paper discusses the conception of multimedia courseware in the teaching of medical imaging technology, and meaning, features and requirements. It is concluded multimedia courseware can play an important role in the teaching of medical imaging technology. Also, some problems existing in the application are analysed in this article.

Objective The aim of this study was to investigate the aquaporin-4(AQP4) expression in the ischemic penumbra tissues.Methods Thirty-six Wistar rats were divided into 7 groups randomly, including control group(n=6) and occluded groups(n=30). The occluded groups were studied after the right middle cerebral artery of the rats unilaterally occluded(MCAO) at an interval of 15 min, 30 min, 1 h, 3 h, 6 h and 24 h, respectively(n=5 for each group). The operation process of the control group was the same as the occluded group except occluded MCAO. Then all rats were imaged with T_1WI, T_2WI and diffusion weighted-imaging(DWI). The brain tissue, according to the method by LIU Meili reported, was regarded as the area of the graphic penumbra. The relative apparent diffusion coefficient of the graphic-penumbra (rADC_1) and the center infarction(rADC_2)(ratios between the values of the occluded side and the opposite side) were calculated. The animals were sacrificed and perfused with the mixture solution consisting of TTC at different time intervals. The graphic-penumbra of the biggest layer of the ischemic cerebral tissue which corresponded to the DWI was examined with immunohistochemistry and RT-PCR. Meanwhile, histologic examination was performed at same site of the lesion. Results There were no significant changes on MRI, the relative apparent diffusion coefficient and the expression of the AQP4. The abnormal high intensity was found on DWI at 15 min after MCAO. T_2WI detected the lesion at 1 h after MCAO. The value of the rADC_1 decreased within 24 h after MCAO in ischemic penumbra, especially, it descended quickly within 1 h after MCAO, from(70.4?6.9)% at 15 min to(53.5?10.9)% at 1 h. Whereas, in the infarct tissue, the changes of the rADC_2 had a rule of decrease from(71.5?6.6)% at 15 min to(45.7?10.5)% at 3 h at first time, and then follow an increasing up to(78.7?11.5)% at 24 h after MCAO. The expression of AQP4 increased gradually within 24 h after MCAO, from 0.42?0.05 at 15 min to 1.18?0.12 at 24 h, it showed negative relationship with the rADC_1 in the ischemic penumbra (r= -0.966,P

Objective: To analyze the association between polycyclic aromatic hydrocarbons(PAHs)exposure and rheumatoid arthritis(RA)based on large sample data. Methods: The RA patients(RA group)and non-RA patients(non-RA group)with complete data were selected from the National Health and Nutrition Survey Database in the United States(NHANES)(2005—2014). The logistic regression model was used to analyze the association between 8 monohydroxylated(OH-)PAH metabolites in the urine and RA. Results: A total of 357 RA patients and 5, 256 non-RA participants were included.After adjusting the confounding factors by logistic analysis, the level of OH-PAHs mixture at the highest quartile(Q4)was associated with increased risk of RA compared with that at the lowest quartile(Q1)(OR=1.60, 95%CI: 1.16-2.23). For a single kind of OH-PAHs, the Q4 levels of 1-hydroxynaphthalene(OR=1.59, 95%CI: 1.14-2.23), 2-hydroxynaphthalene(OR=1.66, 95%CI: 1.19-2.32), 2-hydroxyfluorene(OR=1.61, 95%CI: 1.17-2.22), 3-hydroxyfluorene(OR=1.64, 95%CI: 1.18-2.27)and 1-hydroxyphenanthrene(OR=1.38, 95%CI: 1.00-1.94)were all associated with significantly increased risk of RA compared with the Q1 level(all P<0.05). However, the Q2 level of 1-hydroxypyrene(OR=0.60, 95%CI: 0.43-0.83)was related to a decreased incidence of RA(P<0.01). Conclusions OH-PAHs mixed exposure is a risk factor for RA.The association between the level of individual OH-PAH and the rate of RA is bidirectional and is depended on the type and concentration of OH-PAHs.