This paper establishes an infrared spectral identification key for five natural resins (shellac, sandarac, mastic, copal and rosin) based on their absorbance band positions. These resins may be identified when used in mixtures, such as furniture finishes, at concentrations as low as 1%. Computer methods of deconvolution and spectral subtraction are used to augment this process. The method was v...

The particle size distribution plays an important role in environmental pollution detection and human health protection, such as fog, haze, and soot. In this study, the attractive and repulsive particle swarm optimization algorithm and the basic particle swarm optimization were applied to retrieve the particle size distribution. The spectral extinction technique coupled with the anomalous diffr...

High-frequency open-loop deep brain stimulation (DBS) has been used to alleviate Parkinson's symptoms for almost 20 years. In this issue of Neuron, Rosin et al. present a closed-loop real-time approach that improves DBS and shines light on the etiology of motor symptoms in Parkinson's disease.

In the title compound, C(23)H(34)O(4)·0.5C(2)H(6)O, which was isolated from acrylic modified rosin, the endocyclic compound adopts a tetra-cyclo-[10.2.2.01,10.04,9]hexa-decane structure. In the crystal, the components are linked by O-H⋯O and C-H⋯ hydrogen bonds.

A highly efficient diastereo- and enantioselective Mannich reaction of lactones with a variety of N-Boc-aldimines by using bifunctional rosin-derived amine thiourea catalysts was investigated for the first time, in general, affording the adducts bearing quaternary stereogenic centers with high levels of enantio- and diastereoselectivity (up to 99% ee, and >20:1 dr).

Atomic force microscopy (AFM) is a useful tool for probing pressure sensitive surfaces (PSA) at the micron and sub-micron level. Investigators hope that the spatial resolution of microstructure will provide clues to function. Nevertheless, AFM cannot distinguish functional group chemistry associated with topology. In contrast, FT-IR imaging microscopy is an emerging technology that has the powe...