“Smoky” Quartz

Fractionation of Oxygen Isotopes at the Faces of Smoky Quartz

Recently we reported on a new isotope effect [1]: During the growth of natural amethyst, Si02 with different lsO content is incorporated at crystallo­ graphically different faces of the crystal, the 180 / 160 ratio increasing in the order z-face, r-face, m-face. Meanwhile a similar effect in natural calcite was re­ ported by J. A. D. Dickson [2]. Care must be taken if one wants to single out su...

Non-smoky glycosyltransferase1 prevents the release of smoky aroma from tomato fruit.

Phenylpropanoid volatiles are responsible for the key tomato fruit (Solanum lycopersicum) aroma attribute termed "smoky." Release of these volatiles from their glycosylated precursors, rather than their biosynthesis, is the major determinant of smoky aroma in cultivated tomato. using a combinatorial omics approach, we identified the non-smoky glycosyltransferase1 (NSGT1) gene. Expression of NSG...

Flying the smoky skies: secondhand smoke

From quartz hazard to quartz risk: the coal mines revisited.

Following the classification of quartz as a human carcinogen by the IARC, many standard-setting committees are currently trying to convert this hazard into their national or EU standards. Since human data to set a safe exposure limit for quartz are limited, we hypothesized that lung burden data on quartz in coal miners' lungs after lifetime exposure could be used to set a non-carcinogenic lung ...

Quartz-enhanced photoacoustic spectroscopy.

A new approach to detecting a weak photoacoustic signal in a gas medium is described. Instead of a gas-filled resonant acoustic cavity, the sound energy is accumulated in a high- Q crystal element. Feasibility experiments utilizing a quartz-watch tuning fork demonstrate a sensitivity of 1.2x10(-7) cm(-1) W/ radicalHz . Potential further developments and applications of this technique are discus...