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Abstract Silicon microring modulator plays a critical role in energy-efficient optical interconnect and optical computing owing to its ultra-compact footprint and capability for on-chip wavelength-division multiplexing. However, existing silicon microring modulators usually require more than 2 V of driving voltage (V_pp), which is limited by both material properties and device structures. Here, we present a metal-oxide-semiconductor capacitor microring modulator through heterogeneous integration between silicon photonics and titanium-doped indium oxide, which is a high-mobility transparent conductive oxide (TCO) with a strong plasma dispersion effect. The device is co-fabricated by Intel’s photonics fab and our in-house TCO patterning processes, which exhibits a high modulation efficiency of 117 pm/V and consequently can be driven by a very low V_ppof 0.8 V. At a 11 GHz modulation bandwidth where the modulator is limited by the RC bandwidth, we obtained 25 Gb/s clear eye diagrams with energy efficiency of 53 fJ/bit. 

Abstract SARS-CoV-2 virions enter the host cells by docking their spike glycoproteins to the membrane-bound Angiotensin Converting Enzyme 2. After intracellular assembly, the newly formed virions are released from the infected cells to propagate the infection, using the extra-cytoplasmic ACE2 docking mechanism. However, the molecular events underpinning SARS-CoV-2 transmission between host cells are not fully understood. Here, we report the findings of a scanning Helium-ion microscopy study performed on Vero E6 cells infected with mNeonGreen-expressing SARS-CoV-2. Our data reveal, with unprecedented resolution, the presence of: (1) long tunneling nanotubes that connect two or more host cells over submillimeter distances; (2) large scale multiple cell fusion events (syncytia); and (3) abundant extracellular vesicles of various sizes. Taken together, these ultrastructural features describe a novel intra-cytoplasmic connection among SARS-CoV-2 infected cells that may act as an alternative route of viral transmission, disengaged from the well-known extra-cytoplasmic ACE2 docking mechanism. Such route may explain the elusiveness of SARS-CoV-2 to survive from the immune surveillance of the infected host. 

We report photon pairs and heralded single photons generated at 1310 nm wavelengths using silicon photonics technology, demonstrating that comparable performance could be achieved when a silicon microring resonator was pumped either by a desktop laser instrument or by an electrically injected, room-temperature hybrid silicon laser. Measurements showed that 130 kilo-coincidence-counts per second pair rates could be generated, with coincidences-to-accidentals ratio approximately 100 at about 0.34 mW optical pump power and anti-bunching upon heralding with second-order intensity correlation g(2)(0) = 0.06 at about 0.9 mW optical pump power. These results suggest that hybrid silicon lasers, which are ultra-compact and wafer-scale manufacturable, could be used in place of packaged, stand-alone lasers for generating photon pairs at data communication wavelengths and enable large-scale, cost-effective manufacturing of integrated sources for quantum communications and computing. 

Abstract SARS‐CoV‐2 has led to a worldwide pandemic, catastrophically impacting public health and the global economy. Herein, a new class of lipid‐modified polymer poly (β‐amino esters) (L‐PBAEs) is developed via enzyme‐catalyzed esterification and further formulation of the L‐PBAEs with poly(d,l‐lactide‐coglycolide)‐b‐poly(ethylene glycol) (PLGA‐PEG) leads to self‐assembly into a “particle‐in‐particle” (PNP) nanostructure for gene delivery. Out of 24 PNP candidates, the top‐performing PNP/C12‐PBAE nanoparticles efficiently deliver both DNA and mRNA in vitro and in vivo, presenting enhanced transfection efficacy, sustained gene release behavior, and excellent stability for at least 12 months of storage at −20 °C after lyophilization without loss of transfection efficacy. Encapsulated with spike encoded plasmid DNA and mRNA, the lipid‐modified polymeric PNP COVID‐19 vaccines successfully elicit spike‐specific antibodies and Th1‐biased T cell immune responses in immunized mice even after 12 months of lyophilized storage at −20 °C. This newly developed lipid‐polymer hybrid PNP nanoparticle system demonstrates a new strategy for both plasmid DNA and mRNA delivery with the capability of long‐term lyophilized storage.