Long-term noninvasive cell tracing by fluorescent probes is of great importance to life science and biomedical engineering. For example, understanding genesis, development, invasion and metastasis of cancerous cells and monitoring tissue regeneration after stem cell transplantation require continual tracing of the biological processes by cytocompatible fluorescent probes over a long period of time. In this work, we successfully developed organic far-red/near-infrared dots with aggregation-induced emission (AIE dots) and demonstrated their utilities as long-term cell trackers. The high emission efficiency, large absorptivity, excellent biocompatibility, and strong photobleaching resistance of the AIE dots functionalized by cell penetrating peptides derived from transactivator of transcription proteins ensured outstanding long-term noninvasive in vitro and in vivo cell tracing. The organic AIE dots outperform their counterparts of inorganic quantum dots, opening a new avenue in the development of fluorescent probes for following biological processes such as carcinogenesis.

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Ultrabright organic dots with aggregation-induced emission characteristics (AIE dots) are prepared and shown to exhibit a high quantum yield, a, large two-photon absorption cross-section, and low in vivo toxicity. Real-time two-photon intravital blood vascular imaging in various tissues substantiates that the AIE dots are effective probes for in vivo vasculature imaging in a deep and high-contrast manner.

In addition to high-fat diet (HFD) and inactivity, inflammation and microbiota composition contribute to obesity. Inhibitory immune receptors, such as NLRP12, dampen inflammation and are important for resolving inflammation, but their role in obesity is unknown. We show that obesity in humans correlates with reduced expression of adipose tissue NLRP12. Similarly, Nlrp12 mice show increased weight gain, adipose deposition, blood glucose, NF-κB/MAPK activation, and M1-macrophage polarization. Additionally, NLRP12 is required to mitigate HFD-induced inflammasome activation. Co-housing with wild-type animals, antibiotic treatment, or germ-free condition was sufficient to restrain inflammation, obesity, and insulin tolerance in Nlrp12 mice, implicating the microbiota. HFD-fed Nlrp12 mice display dysbiosis marked by increased obesity-associated Erysipelotrichaceae, but reduced Lachnospiraceae family and the associated enzymes required for short-chain fatty acid (SCFA) synthesis. Lachnospiraceae or SCFA administration attenuates obesity, inflammation, and dysbiosis. These findings reveal that Nlrp12 reduces HFD-induced obesity by maintaining beneficial microbiota.

We demonstrate through PdO doping that creation of heterojunctions on Co3O4 nanoparticles can quantitatively adjust band-gap and Fermi energy levels to study the impact of metal oxide nanoparticle semiconductor properties on cellular redox homeostasis and hazard potential. Flame spray pyrolysis (FSP) was used to synthesize a nanoparticle library in which the gradual increase in the PdO content (0–8.9%) allowed electron transfer from Co3O4 to PdO to align Fermi energy levels across the heterojunctions. This alignment was accompanied by free hole accumulation at the Co3O4 interface and production of hydroxyl radicals. Interestingly, there was no concomitant superoxide generation, which could reflect the hole dominance of a p-type semiconductor. Although the electron flux across the heterojunctions induced upward band bending, the Ec levels of the doped particles showed energy overlap with the biological redox potential (BRP). This allows electron capture from the redox couples that maintain the BRP from −4.12 to −4.84 eV, causing disruption of cellular redox homeostasis and induction of oxidative stress. PdO/Co3O4 nanoparticles showed significant increases in cytotoxicity at 25, 50, 100, and 200 μg/mL, which was enhanced incrementally by PdO doping in BEAS-2B and RAW 264.7 cells. Oxidative stress presented as a tiered cellular response involving superoxide generation, glutathione depletion, cytokine production, and cytotoxicity in epithelial and macrophage cell lines. A progressive series of acute pro-inflammatory effects could also be seen in the lungs of animals exposed to incremental PdO-doped particles. All considered, generation of a combinatorial PdO/Co3O4 nanoparticle library with incremental heterojunction density allowed us to demonstrate the integrated role of Ev, Ec, and Ef levels in the generation of oxidant injury and inflammation by the p-type semiconductor, Co3O4.

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Background: A pneumonia associated with the coronavirus disease 2019 (COVID-19) recently emerged in China. It was recognized as a global health hazard. Methods: 234 inpatients with COVID-19 were included. Detailed clinical data, chest HRCT basic performances and certain signs were recorded Ground-glass opacity (GGO), consolidation, fibrosis and air trapping were quantified. Both clinical types and CT stages were evaluated. Results: Most patients (approximately 90%) were classified as common type and with epidemiologic history. Fever and cough were main symptoms. Chest CT showed abnormal attenuation in bilateral multiple lung lobes, distributed in the lower and/or periphery of the lungs (94.98%), with multiple shapes. GGO and vascular enhancement sign were most frequent seen, followed by interlobular septal thickening and air bronchus sign as well as consolidation, fibrosis and air trapping. There were significant differences in most of CT signs between different stage groups. The SpO2 and OI were decreased in stage IV, and the CT score of consolidation, fibrosis and air trapping was significantly lower in stage I (P < 0.05). A weak relevance was between the fibrosis score and the value of PaO2 and SpO2 (P < 0.05). Conclusions: Clinical performances of patients with COVID-19, mostly with epidemiologic history and typical symptoms, were critical valuable in the diagnosis of the COVID-19. While chest HRCT provided the distribution, shape, attenuation and extent of lung lesions, as well as some typical CT signs of COVID-19 pneumonia.

Molecular electronic control over plasmons offers a promising route for on-chip integrated molecular plasmonic devices for information processing and computing. To move beyond the currently available technologies and to miniaturize plasmonic devices, molecular electronic plasmon sources are required. Here, we report on-chip molecular electronic plasmon sources consisting of tunnel junctions based on self-assembled monolayers sandwiched between two metallic electrodes that excite localized plasmons, and surface plasmon polaritons, with tunnelling electrons. The plasmons originate from single, diffraction-limited spots within the junctions, follow power-law distributed photon statistics, and have well-defined polarization orientations. The structure of the self-assembled monolayer and the applied bias influence the observed polarization. We also show molecular electronic control of the plasmon intensity by changing the chemical structure of the molecules and by bias-selective excitation of plasmons using molecular diodes.S urface plasmon polaritons (SPPs) confine and enhance local electromagnetic fields near surfaces of metallic nanostructures at optical frequencies and have the ability to propagate along subdiffractive metallic waveguides, thereby opening up new perspectives for integrated optoelectronic circuits at the nanoscale 1-4 . However, almost all these applications use large external light sources such as monochromatic lasers. To minimize the size of the light sources and ultimately the size of the plasmonic devices, plasmons have been excited on-chip using electrically driven light sources such as (organic) light-emitting diodes (LEDs) 5-8 , laser diodes 9 , silicon spheres 10 and single carbon nanotubes 11 instead of bulky lasers. Surface plasmons have also been directly excited by tunnelling electrons in metal-insulator-metal junctions based on metal oxides 12-14 or scanning tunnelling microscopes (STMs) using vacuum or molecular tunnelling barriers [15][16][17][18][19][20][21][22][23][24][25] . During the tunnelling process, most of the electrons tunnel elastically, but some tunnel inelastically and couple to a plasmon mode. Direct excitation of plasmons by tunnelling electrons is attractive because not only is no background light generated but potentially it is also fast 26 (on the timescale of quantum tunnelling) as no slow electron-hole recombination processes are required as is the case for electroluminescent (nano)light sources 5-11 . Here, we report a direct electronic plasmon source based on molecular tunnel junctions operating via throughmolecular-bond tunnelling, where the plasmonic properties can be electrically controlled at the molecular level (without the need for optical antennas 27,28 ).In molecular electronic devices, the tunnelling barrier height is defined by the electronic energy levels of the molecule(s) bridging two electrodes. The tunnelling barrier width is defined by the length of the bridging molecule. Hence, the tunnelling gaps in molecular electronic devices are always exact...