Polarization-insensitive optical modulators allow an external laser to be remotely interconnected by single-mode optical fibers while avoiding polarization controllers,which would be convenient and cost-effective for ...Polarization-insensitive optical modulators allow an external laser to be remotely interconnected by single-mode optical fibers while avoiding polarization controllers,which would be convenient and cost-effective for co-packaged optics,5G,and future 6G applications.In this article,a polarization-insensitive silicon intensity modulator is proposed and experimentally demonstrated based on two-dimensional centrally symmetric gratings,featuring a low polarization-dependent loss of 0.15 dB in minimum and polarization insensitivity of eye diagrams.The device exhibits a low fiber-to-fiber insertion loss of 9 dB and an electro-optic(EO)bandwidth of 49.8 GHz.A modulation speed of up to 224 Gb/s is also demonstrated.展开更多
Most mammalian cells take up cholesterol from low-density lipoproteins(LDLs) via receptor-mediated endocytosis.After reaching lysosomes,LDL-derived cholesterol continues to transport to downstream organelles including...Most mammalian cells take up cholesterol from low-density lipoproteins(LDLs) via receptor-mediated endocytosis.After reaching lysosomes,LDL-derived cholesterol continues to transport to downstream organelles including the ER for specific structural and functional needs.Peroxisomes are recently found to receive cholesterol from lysosomes through lysosomeperoxisome membrane contacts.However,whether and how cholesterol is conveyed from peroxisomes to the ER remain unknown.Here,by combining high-resolution microscopic analyses and in vitro reconstitution of highly purified organelles or artificial liposomes,we demonstrate that peroxisomes form membrane contacts with the ER through the interaction between peroxisomal PI(4,5)P2 and ER-resident extended synaptotagmin-1,2 and 3(E-Syts).Depletion of peroxisomal PI(4,5)P2 or ESyts markedly decreases peroxisome-ER membrane contacts and induces cholesterol accumulation in lysosomes.Furthermore,we show that cholesterol is delivered from 3H-labeled peroxisomes or PI(4,5)P2-containing liposomes to the ER in vitro,and that the presence of peroxisomes augments cholesterol transfer from lysosomes to the ER.Together,our study reveals a new cholesterol transport pathway along the lysosome-peroxisome-ER membrane contacts in the cell.展开更多
基金National Natural Science Foundation of China(62341508,61974099,62022081)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2022045)+1 种基金Major Key Project of Peng Cheng LaboratoryOpen Project of Tianjin Key Laboratory of Optoelectronic Detection Technology and System(2024LODTS104)。
文摘Polarization-insensitive optical modulators allow an external laser to be remotely interconnected by single-mode optical fibers while avoiding polarization controllers,which would be convenient and cost-effective for co-packaged optics,5G,and future 6G applications.In this article,a polarization-insensitive silicon intensity modulator is proposed and experimentally demonstrated based on two-dimensional centrally symmetric gratings,featuring a low polarization-dependent loss of 0.15 dB in minimum and polarization insensitivity of eye diagrams.The device exhibits a low fiber-to-fiber insertion loss of 9 dB and an electro-optic(EO)bandwidth of 49.8 GHz.A modulation speed of up to 224 Gb/s is also demonstrated.
基金supported by the National Natural Science Foundation of China (91754102, 31771568, 31690102, 31600651, 31701030)National Key Research and Development Project of the Ministry of Science and Technology of China (2016YFA0500100)+2 种基金Shenzhen City Technology Basic Research Program (JCYJ20170818144026198)Science and Technology Department of Hubei Province (2017CFB617)the 111 Project of Ministry of Education of China (B16036)
文摘Most mammalian cells take up cholesterol from low-density lipoproteins(LDLs) via receptor-mediated endocytosis.After reaching lysosomes,LDL-derived cholesterol continues to transport to downstream organelles including the ER for specific structural and functional needs.Peroxisomes are recently found to receive cholesterol from lysosomes through lysosomeperoxisome membrane contacts.However,whether and how cholesterol is conveyed from peroxisomes to the ER remain unknown.Here,by combining high-resolution microscopic analyses and in vitro reconstitution of highly purified organelles or artificial liposomes,we demonstrate that peroxisomes form membrane contacts with the ER through the interaction between peroxisomal PI(4,5)P2 and ER-resident extended synaptotagmin-1,2 and 3(E-Syts).Depletion of peroxisomal PI(4,5)P2 or ESyts markedly decreases peroxisome-ER membrane contacts and induces cholesterol accumulation in lysosomes.Furthermore,we show that cholesterol is delivered from 3H-labeled peroxisomes or PI(4,5)P2-containing liposomes to the ER in vitro,and that the presence of peroxisomes augments cholesterol transfer from lysosomes to the ER.Together,our study reveals a new cholesterol transport pathway along the lysosome-peroxisome-ER membrane contacts in the cell.
