An official website of the United States government
Abstract The classical properties of thermal light fields were instrumental in shaping our early understanding of light. Before the invention of the laser, thermal light was used to investigate the wave-particle duality of light. The subsequent formulation of the quantum theory of electromagnetic radiation later confirmed the classical nature of thermal light fields. Here, we fragment a pseudothermal field into its multiparticle constituents to demonstrate that it can host multiphoton dynamics mediated by either classical or quantum properties of coherence. This is shown in a forty-particle system through a process of scattering mediated by twisted paths endowed with orbital angular momentum. This platform enables accurate projections of the scattered pseudothermal system into isolated multiphoton subsystems governed by quantum dynamics. Interestingly, the isolated multiphoton subsystems exhibiting quantum coherence produce interference patterns previously attributed to entangled optical systems. As such, our work unveils novel mechanisms to isolate quantum systems from classical fields. This possibility opens new paradigms in quantum physics with enormous implications for the development of robust quantum technologies.
more »
« less
Visible Light‐Responsive Dynamic Biomaterials: Going Deeper and Triggering More
Abstract Photoresponsive materials have been widely used in vitro for controlled therapeutic delivery and to direct 4D cell fate. Extension of the approaches into a bodily setting requires use of low‐energy, long‐wavelength light that penetrates deeper into and through complex tissue. This review details recent reports of photoactive small molecules and proteins that absorb visible and/or near‐infrared light, opening the door to exciting new applications in multiplexed and in vivo regulation.
more »
« less
- Award ID(s):
- 1652141
- PAR ID:
- 10458123
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Healthcare Materials
- Volume:
- 9
- Issue:
- 7
- ISSN:
- 2192-2640
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Sea ice plays a critical role in the climate system through its albedo, which constrains light transmission into the upper ocean. In spring and summer, light transmission through sea ice is influenced by its iconic blue melt ponds, which significantly reduce surface albedo. We show that the geometry of surface melt ponds plays an important role in the partitioning of instantaneous solar radiation under sea ice by modeling the three‐dimensional light field under ponded sea ice. We find that aggregate properties of the instantaneous sub‐ice light field, such as the enhancement of available solar energy under bare ice regions, can be described using a new parameter closely related to pond fractal geometry. We then explore the influence of pond geometry on the ecological and thermodynamic sea ice processes that depend on solar radiation.more » « less
-
Abstract The light chain of tetanus neurotoxin (TeNT) is a 52 kD metalloprotease that potently inhibits synaptic transmission by cleaving the endogenous vesicle fusion protein VAMP2. To mitigate the toxicity of TeNT and harness it as a conditional tool for neuroscience, we engineered Light-Activated TeNT (LATeNT) via insertion of the light-sensitive LOV domain into an allosteric site. LATeNT was optimized by directed evolution and shown to have undetectable activity in the dark mammalian brain. Following 30 seconds of weak blue light exposure, however, LATeNT potently inhibited synaptic transmission in multiple brain regions. The effect could be reversed over 24 hours. We used LATeNT to discover an interneuron population in hippocampus that controls anxiety-like behaviors in mouse, and to control the secretion of endogenous insulin from pancreatic beta cells. Synthetic circuits incorporating LATeNT converted drug, Ca2+, or receptor activation into transgene expression or reporter protein secretion. Due to its large dynamic range, rapid kinetics, and highly specific mechanism of action, LATeNT should be a robust tool for conditional proteolysis and spatiotemporal control of synaptic transmissionin vivo.more » « less
-
Abstract Aureococcus anophagefferens forms a model host-virus system with the “giant virus” Kratosvirus quantuckense. Studies to define its ribocell (uninfected) and virocell (virus-infected) forms are needed as these states co-occur during algal blooms. Previously, a link between light-derived energy, virus particle production, and virocell formation was noted. We explored how the time of day (morning, midday, or late day) of virus-host contact shaped virocell ontogeny. In parallel, we explored the dependence on light-derived energy in this mixotrophic plankter by inhibiting photosystem II, testing the role of heterotrophic energy in infection dynamics. Using flow cytometry and photochemical assessments, we examined the physiology of infected cells and controls, and estimated virus particle production. We observed differences between ribocell and virocell response to treatments, including reductions in virus particle production during reduced light duration) and PSII inhibition (i.e. “forced heterotrophy”). This work demonstrates the importance of light in shaping the fate of infected cells and provides insight into factors that constrain in situ blooms. Most significantly, we show that time of the solar day when a virus and host come into contact influences viral particle production, and therefore bloom dynamics; a factor that needs to be considered in bloom modeling work.more » « less
-
Abstract The ability to optically induce biological responses in 3D has been dwarfed by the physical limitations of visible light penetration to trigger photochemical processes. However, many biological systems are relatively transparent to low‐energy light, which does not provide sufficient energy to induce photochemistry in 3D. To overcome this challenge, hydrogels that are capable of converting red or near‐IR (NIR) light into blue light within the cell‐laden 3D scaffolds are developed. The upconverted light can then excite optically active proteins in cells to trigger a photochemical response. The hydrogels operate by triplet–triplet annihilation upconversion. As proof‐of‐principle, it is found that the hydrogels trigger an optogenetic response by red/NIR irradiation of HeLa cells that have been engineered to express the blue‐light sensitive protein Cry2olig. While it is remarkable to photoinduce the clustering of Cry2olig with blanket NIR irradiation in 3D, it is also demonstrated how the hydrogels trigger clustering within a single cell with great specificity and spatiotemporal control. In principle, these hydrogels may allow for photochemical control of cell function within 3D scaffolds, which can lead to a wealth of fundamental studies and biochemical applications.more » « less
