Two-photon luminescence with near-infrared(NIR)excitation of upconversion nanoparticles(NPs)is of great importance in biological imaging due to deep penetration in high-scattering tissues,low auto-luminescence and goo...Two-photon luminescence with near-infrared(NIR)excitation of upconversion nanoparticles(NPs)is of great importance in biological imaging due to deep penetration in high-scattering tissues,low auto-luminescence and good sectioning ability.Unfortunately,common two-photon luminescence is in visible band with an extremely high exciation power density,which limits its application.Here,we synthesized NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs with strong twophoton NIR emission and a low excitation power density.Furthermore,NaYF_(4):Yb/Tm@NaYF_(4)@SiO_(2)@OTMS@F127 NPs with high chemical stability were obtained by a modified multilayer coating method which was applied to upconversion NPs for thefirst time.In addition,it is shown that the as-prepared hydrophillic upconversion NPs have great biocompatibility and kept stable for 6 hours during in vivo whole-body imaging.The vessels with two-photon luminescence were clear even under an excitation power density as low as 25mW/cm^(2).Vivid visualizations of capillaries and vessels in a mouse brain were also obtained with low background and high contrast.Because of cheaper instruments and safer power density,the NIR two-photon luminescence of NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs could promote wider application of two-photon technology.The modified multilayer coating method could be widely used for upconversion NPs to increase the stable time of the in vivo circulation.Our work possesses a great potential for deep imaging and imaging-guided treatment in the future.展开更多
Basilar artery fenestration is a rare anatomical variation resulting from the failed fusion of the two vertebral arteries during embryonic life. In order of frequency, it is the second most common location of vascular...Basilar artery fenestration is a rare anatomical variation resulting from the failed fusion of the two vertebral arteries during embryonic life. In order of frequency, it is the second most common location of vascular fenestrations after the anterior communicating artery. Vertebrobasilar junction aneurysms are uncommon but often associated with basilar artery fenestration. We report the case of a fenestrated vertebrobasilar junction saccular aneurysm in a 57-year-old woman. The diagnosis was incidentally made on CT angiography which found the anatomical variant and the aneurysm. The radiological features illustrating this association are detailed here and a brief discussion of its pathogenesis and management was made. Vertebrobasilar junction aneurysms are rare and their presence should suggest an associated basilar fenestration.展开更多
基金This work is partially supported by National Key Research and Development Program of China(Grant No.2018YFC1407503)the Fundamental Research Funds for the Central Universities(2018FZA5001)The National Natural Science Foundation of China(Grant No.11621101).
文摘Two-photon luminescence with near-infrared(NIR)excitation of upconversion nanoparticles(NPs)is of great importance in biological imaging due to deep penetration in high-scattering tissues,low auto-luminescence and good sectioning ability.Unfortunately,common two-photon luminescence is in visible band with an extremely high exciation power density,which limits its application.Here,we synthesized NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs with strong twophoton NIR emission and a low excitation power density.Furthermore,NaYF_(4):Yb/Tm@NaYF_(4)@SiO_(2)@OTMS@F127 NPs with high chemical stability were obtained by a modified multilayer coating method which was applied to upconversion NPs for thefirst time.In addition,it is shown that the as-prepared hydrophillic upconversion NPs have great biocompatibility and kept stable for 6 hours during in vivo whole-body imaging.The vessels with two-photon luminescence were clear even under an excitation power density as low as 25mW/cm^(2).Vivid visualizations of capillaries and vessels in a mouse brain were also obtained with low background and high contrast.Because of cheaper instruments and safer power density,the NIR two-photon luminescence of NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs could promote wider application of two-photon technology.The modified multilayer coating method could be widely used for upconversion NPs to increase the stable time of the in vivo circulation.Our work possesses a great potential for deep imaging and imaging-guided treatment in the future.
文摘Basilar artery fenestration is a rare anatomical variation resulting from the failed fusion of the two vertebral arteries during embryonic life. In order of frequency, it is the second most common location of vascular fenestrations after the anterior communicating artery. Vertebrobasilar junction aneurysms are uncommon but often associated with basilar artery fenestration. We report the case of a fenestrated vertebrobasilar junction saccular aneurysm in a 57-year-old woman. The diagnosis was incidentally made on CT angiography which found the anatomical variant and the aneurysm. The radiological features illustrating this association are detailed here and a brief discussion of its pathogenesis and management was made. Vertebrobasilar junction aneurysms are rare and their presence should suggest an associated basilar fenestration.
