The use of light as treatment dates back to ancient civilizations. However, it was the discovery green fluorescent protein that led a paradigm shift in our ability observe and study cellular processes. Applying investigation spatial temporal dynamics location, structure, function has enabled biological discoveries were previously unimaginable made significant contributions both understanding hu...

Irradiation of the dinucleotide TpBU at all wavelengths from 240 to 295 m/u produces a debrominated photoproduct and two minor products. The main compound has an absorption maxi­ mum exactly at the same wavelength as the parent compound, but with approximately half the value of the extinction coefficient. It cannot be reverted by short wavelengths, such as 240 m/j,. Consistent with our observat...

reactions of 1 ,zdihydropyridines (la-c) and 1,4-dihydropyridines (2a-c) in the presence of benzyne (3) under thermal conditions, and in the case of (2c) under photochemical conditions, have been investigated. benzyne acts as an oxidizing agent to convert dihydropyridine (la) and (2a) to the corresponding pyridine (4) or adds as a dienophile to (lb-c).

Light availability is considered a key factor regulating the thermal sensitivity of reef building corals, where excessive excitation of photosystem II (PSII) further exacerbates pressure on photochemical pathways already compromised by heat stress. Coral symbionts acclimate to changes in light availability (photoacclimation) by continually fine-tuning the photochemical operating efficiency of P...

The effects of temperature, pressure, solvent, and substrate concentration upon several enantioand diastereodifferentiating photochemical reactions have been investigated and discussed in detail. These entropy-related external factors, which manipulate the weak electronic and steric interactions in the excited state, dynamically control the stereochemical outcome of asymmetric photochemical rea...

As an important precursor of hydroxyl radical, nitrous acid (HONO) plays a key role in the chemistry of the lower atmosphere. Recent atmospheric measurements and model calculations show strong enhancement for HONO formation during daytime, while they are inconsistent with the known sources in the atmosphere, suggesting that current models are lacking important sources for HONO. In this article,...

The principal objective of this work has been to assess the quantitative importance of homogenous and heterogeneous photochemistry as a sink of pollutants in the aquatic environment. Using a combination of chemical trapping techniques, steady-state and time-resolved spectroscopic methods and product analysis, we have examined the mechanisms and magnitude of the photochemical production of stron...