In lipid biochemistry, a fundamental question is how the potential number of fatty acids increases with their chain length. Here, we show that it grows according to the famous Fibonacci numbers when cis/trans isomerism is neglected. Since the ratio of two consecutive Fibonacci numbers tends to the Golden section, 1.618, organisms can increase fatty acid variability approximately by that factor ...

The cardiac specialized conduction tissue was studied by serial sectioning in 13 cases of situs ambiguus. In four cases of right isomerism, we found paired sinus nodes in relation to a crista terminalis, and in each case a sling of conduction tissue between two atrioventricular nodes was present regardless of the ventricular morphology or cardiac position. In the cases with left isomerism, the ...

Sixteen isomers of heterometallic germanium clusters have been analysed in this review. There are two types of isomerism, distortion (x 15) and cis – trans (x 1) and cis – isomer contains two crystallographically independent molecules. Distortion isomers, differing only by degree of distortion in Ge – L, Ge – M (M = metal) distances and L – Ge L (L = ligand) angles. The data are discussed with ...

We introduce the mixed product of three vectors spanning four molecular locations as a descriptor of optical isomerism. This descriptor is very efficient as it does not require molecular superposition, and is very robust in discriminating between a given isomer and its mirror image. In particular, conformational isomers that are mirror images of each other, as well as optical isomers have oppos...

Several hypotheses to elucidate the linkage isomer preference of the thiocyanate (SCN(-)) ion have been offered. For complexes with small coordination numbers (i.e., 1 and 2) and groups 11 (Cu-triad) and 12 (Zn-triad) metals, different levels of theory and a variety of basis sets have been employed to study linkage isomerism. Similar results are obtained for all density functionals tested, pure...

Molecular endofullerenes are supramolecular systems consisting of fullerene cages encapsulating small molecules. Although most early examples consist of encapsulated metal clusters, recently developed synthetic routes have provided endofullerenes with non-metallic guest molecules in high purity and macroscopic quantities. The encapsulated light molecule behaves as a confined quantum rotor, disp...

In the present work, we have investigated the conformational isomerism and calculated the vibrational spectra of the C4 oxygenates: 3-butyne-2-one, 3-butene-2-one, 2-butanone and 2-butanol using density functional theory. The calculations are validated by comparison to structural data where available and new, experimental inelastic neutron scattering and infrared spectra of the compounds. We fi...

The organometallic chemistry of platinum covers a huge field, as shown by a recent survey covering the crystallographic and structural data of almost one thousand organometallic derivatives. About nine percent of those derivatives exist as isomers and are summarized in this review and include distortion (90 %), cis trans (6%) and ligand isomerism (4%). These are discussed in terms of the coordi...

Left-right (L-R) asymmetry is a fundamental feature of higher-order neural function. However, the molecular basis of brain asymmetry remains unclear. We recently reported L-R asymmetry of hippocampal circuitry caused by differential allocation of N-methyl-D-aspartate receptor (NMDAR) subunit GluRepsilon2 (NR2B) in hippocampal synapses. Using electrophysiology and immunocytochemistry, here we an...

We report the prenatal diagnosis of total anomalous pulmonary venous connection to the portal system in a 20-week fetus with right atrial isomerism. The apex of the fetal heart pointed to the left, the fetal stomach was on the right, there was a common atrioventricular valve, the left ventricle was small and the abdominal aorta and inferior vena cava were on the left side; all these features we...