Graphene oxide(GO)/Ag nanoparticle(NP) hybrids are obtained by in situ reduction of Ag NPs on GO sheets.In this letter,the influence of the conformation of GO sheets on the surface-enhanced Raman scattering(SERS) effect of GO/Ag NPs is investigated by covalently grafting folic acid(FA) molecules onto graphite sheets.SERS measurements are conducted in aqueous solutions with different pH values.Data show that the SERS signals of FA are pH dependent,consistent with the morphological changes of GO sheets.
通过观察镁离子对紫外线辐射损伤后细胞活性与光产物产量的影响,以明确镁离子对UVB辐射细胞损伤的防护作用。在实验中,选择成人成纤维细胞(HDF-a)和角质形成细胞(HaCaT)进行细胞培养,筛选小剂量UVB辐射进行诱导性损伤,观察不同浓度镁离子(0.1 mm ol/L,0.2 mm ol/L,0.4 mm ol/L,0.8 mm ol/L,1.2 mm ol/L)对辐射损伤的细胞活性、基因组断裂情况及光产物产量的影响。研究结果显示,在UVB辐射后,两个细胞系细胞活性显著下降,镁离子培养液孵育的细胞活性均比UVB辐射损伤对照组显著升高,而镁离子孵育后细胞光产物嘧啶二聚体(CPD s)量明显减少。实验研究证实,镁离子对UVB辐射损伤的培养细胞具有防护作用,为UV辐射所致的DNA损伤的修复提供理论基础。
Using the optical coherence tomography(OCT) images,the optical attenuation coefficients(μ_t) of human Laogong acupoint and non-acupoint tissues are measured after empty irradiation and 808-nm 100-mW irradiation for 10 min in vivo non-invasively.The results show that there is no significant difference ofμ_t of Laogong acupoint and non-acupoint tissues after empty irradiation.However,there are significant differences ofμ_t between Laogong acupoint and non-acupoint tissues after laser irradiation at the power of 100 mW(statistical definition of probability p<0.01).The results of the pilot study indicate that the OCT could distinguish the acupoint from the surrounding tissues after irradiation with laser in vivo non-invasively.
