Dynamics of hydrogen shift reactions between peroxy radicals.

Peroxy radicals are key intermediates in many atmospheric processes. Reactions between such radicals are of particular interest as they can lead to accretion products capable of participating in new particle formation (NPF). These reactions proceed through a tetroxide intermediate, which then decomposes to a complex of two alkoxy radicals and O, with spin conservation dictating that the complex must be formed in the triplet state.

Wavelength-dependent intersystem crossing dynamics of phenolic carbonyls in wildfire emissions.

Quantum chemical calculations were employed to construct Jablonski diagrams for a series of phenolic carbonyls, including vanillin, iso-vanillin, 4-hydroxybenzaldehyde, syringaldehyde, and coniferyl aldehyde. These molecules can enter the Earth's atmosphere from forest fire emissions and participate in photochemical reactions within the atmospheric condensed phase, including cloud and fog droplets and aqueous aerosol particles. This photochemistry alters the composition of light-absorbing organic content, or brown carbon, in droplets and particles through the formation and destruction of key chromophores.

Shedding new light on quadrupolar 1,4-dihydropyrrolo[3,2-]pyrroles: impact of electron-deficient scaffolds over emission.

In this work, we disclose a series of seven quadrupolar centrosymmetric 1,4-dihydropyrrolo[3,2-]pyrroles (DHPPs) linked to the two peripheral, strongly electron-accepting heterocycles such as benzoxadiazole, benzothiadiazole and benzoselenadiazole. This represents the first study probing the influence of electron-deficient heterocycles, rather that small electron-withdrawing substituents, on photophysics of DHPPs. These new acceptor-donor-acceptor hybrid dyes exhibit an appreciable combination of photophysical properties including absorption maxima in the range of 470-620 nm, and emission in the range of 500-720 nm with fluorescence quantum yields reaching 0.

Association of the Genotype of TNFα with the Efficiency of the Intensive Phase of Chemotherapy and Formation of the Sizes of Destruction Cavities in Patients with Pulmonary Tuberculosis.

The interrelation between the TNFα gene polymorphism and the effectiveness of the intensive phase of chemotherapy in patients with pulmonary tuberculosis, as well as the formation of diameter of the sizes of destruction cavities was studied. It was revealed that the most adverse course of the disease and a high frequency of formation of destruction cavities are associated with the GG genotype of the TNFα gene.

Nonradiative Deactivation of the Fluorescent Ag-DNA and Ag-DNA Emitters: The Role of Water.

The luminescent quantum yield of silver-cluster emitters stabilized by short oligonucleotides (Ag-DNA) may be efficiently tuned by replacing nucleobases in their stabilization DNA matrices with analogues. In the present study, we proposed a valuable and straightforward theoretical methodology for assessing the photophysical behaviors emerging in Ag-DNA emitters after excitation. Using green Ag-DNA and near-IR Ag-DNA emitters we demonstrate how point guanine/inosine replacement could affect the photophysical rate constants of radiative/nonradiative processes.