Quantitative-structure-toxicity-relationship (QSTR) models are developed for predicting the toxicity (pIGC 50 ) of 252 aliphatic compounds on Tetrahymena pyriformis . The single parameter models with a simple molecular descriptor, the number of atoms in the molecule, provide reasonable results. Better...
Returning to our task of counting the water molecules in a liter of water, we know that a liter of water weighs 1,000 grams; unfortunately, we also need the weight per molecule of water in order to calculate the number of water molecules. For coins or skateboard wheels, we can pick up...
The distribution of single-cell properties across a population of cells can be measured using diverse tools, but no technology directly quantifies the biochemical stimulation events regulating these properties. Here we report digital counting of growth factors in single cells using fluorescent quantum do...
PURPOSE: To stop component supply devices in sequence so that the total number of components supplied from the component supply devices is decreased stepwise and to restart supplying components from the component supply devices a certain time later and performing quantitative counting operation up to tw...
Our current understanding of the metabolism of endogenous andxenobioticcompounds has come in the main from the use of molecules labelled withradioisotopes. The compound under investigation is synthesised so that selected atoms in the molecule are enriched with the desiredradioisotope. The resulting radio...
These (e,3e) experiments are be- lieved (24, 25) to provide a more detailed picture of elec- tron correlations in atoms and molecules. 2. Theoretical background Electron momentum spectroscopy is based on the (e,2e) reaction, FIG.1. Vector diagram showing collision geometry for the (e,...
The average air temperature was2.2°C above the 1981-2010 normalof 16.7°C, and it was thewarmest summer ever recorded in more than 150 years. The number of extreme warm days and warm nights was also the highest recorded, going back several decades. ...
A simple descriptor, viz the number of carbon (Nc)/non-hydrogenic (NNH) atoms present in a molecule, is proposed for the development of useful Quantitative Structure -Property-Relationship (QSPR) models. This work is prompted by that of Randic and Basak (J. Chem. Inf. Comput. Sci. 2001,...
organic molecule configurationspolynomials/ perfect matching countingbenzenoid chainsnomenclaturehexagonal chainsrecurrence formulaspolynomial expressions/ A3110 General theory of structure, transitions and chemical binding in atoms and molecules A3520B General molecular conformation and symmetry...
Hunt, D.F., Sethi, S.K.: Gas-phase ion/molecule isotope-exchange reactions: methodology for counting hydrogen atoms in specific organic structural environments by chemical ionization mass spectrometry. J. Am. Chem. Soc. 102, 6953-6963 (1980)...