Conjugation-length dependence of regioregular oligo 3-alkyl(thienylene-vinylene)s demonstrates polyene-like behaviour with weak electron-electron correlations.

Poly(3-alkyl(thienylene-vinylene)) (P3TV) and its longer oligomers have negligibly low photoluminescence quantum yields, however, the reason for their low yields is currently debated. Here, we prepare a series of regioregular (3-dodecyl)thienylene-vinylene oligomers with n = 2-8 repeat units by iterative Horner-Wadsworth-Emmons reactions, and report their steady-state, transient absorption, and emission spectroscopy. The results presented here demonstrate that 3-alkyl(thienylene-vinylene) oligomers form part of the polyene family. The shortest (n = 2) oligomer emits from the bright 1Bu state, while fluorescence in oligomers with n = 3, 4 is from the formally dark 2Ag state, allowed via Herzberg-Teller vibronic coupling to the nearby bright 1Bu state as described for diphenyl-polyenes. Longer oligomers and the polymer are essentially non-emissive as the 2Ag state can no longer intensity-borrow from the 1Bu state. We demonstrate that the spectral shapes, photoluminescence quantum yield, and transient spectral behaviour can all be explained using a polyene model with weak electronic correlations.

Growth of Plasmonic Nanoparticles for Aging Cask-Matured Whisky.

The maturation of spirit in wooden casks is key to the production of whisky, a hugely popular and valuable product, with the transfer and reaction of molecules from the wooden cask with the alcoholic spirit imparting color and flavor. However, time in the cask adds significant cost to the final product, requiring expensive barrels and decades of careful storage. Thus, many producers are concerned with what "age" means in terms of the chemistry and flavor profiles of whisky. We demonstrate here a colorimetric test for spirit "agedness" based on the formation of gold nanoparticles (NPs) by whisky. Gold salts were reduced by barrel-aged spirit and produce colored gold NPs with distinct optical properties. Information from an extinction profile, such as peak position, growth rate, or profile shape, was analyzed, and our assay output was correlated with measurements of the whisky sample makeup, assays for key functional groups, and spiking experiments to explore the mechanism in more detail. We conclude that age is not just a number, that the chemical fingerprint of key flavor compounds is a useful marker for determining whisky "age", and that our simple reduction assay could assist in defining the aged character of a whisky and become a useful future tool on the warehouse floor.

Loss of utility of bone marrow biopsy as a staging evaluation for Hodgkin lymphoma in the positron emission tomography-computed tomography era: a West of Scotland study.

Abstract Positron emission tomography-computed tomography (PET-CT) scanning has been shown to be more sensitive than bone marrow biopsy (BMB) in detecting bone marrow involvement (BMI) in classical Hodgkin lymphoma (cHL). In this 5-year retrospective series, 93 (54%) of all new cases of cHL were staged using PET-CT and BMB. PET-CT identified focal bone marrow uptake in 17/93 (18.3%), whilst only five of these (29.4%) were confirmed by BMB. Abnormal pelvic uptake was seen on PET-CT in these five cases. The other 12 cases were missed, giving BMB a sensitivity of 29.4% and a specificity of 100%. PET-CT upstaged 9.7% of patients compared to CT alone. BMB upstaged only one patient; however, this patient was already stage IV on PET-CT. BMB did not alter clinical management in any case. Bone positivity on PET-CT appeared to correlate with anemia, raised lactate dehydrogenase (LDH) and B symptoms. BMB has little or nothing to offer staging cHL in the PET-CT era.