Ventricular tachycardia in the setting of a large cardiac fibroma in a pediatric patient.

Ventricular tachycardia and cardiac tumors are both extremely rare diagnoses in pediatric patients. We report a pediatric case of cardiac fibroma that was noted during the work up of ventricular tachycardia in a young patient concomitantly diagnosed with severe acute respiratory syndrome coronavirus 2.

New N,N,N-heteroscorpionates based on 2,2'-bis(pyrazolyl)ethanamine and its derivatives. Ligands designed for probing supramolecular interactions.

The successful design and synthesis of the new bis(pyrazolyl)ethanamine ligand and its copper(I) triphenylphosphine complex is reported. The ligand coordinates to the copper(I) center in a fac tridentate fashion, through both the pyrazolyl rings and the nitrogen atom from the NH2 group. In the solid state, the compound is organized in a 2D noncovalent network by N-H...pi and C-H...pi interactions and hydrogen bonds. The analogous ligand with a benzyl group substituted on the amine forms a complex with the same copper(I) center that has a similar 2D supramolecular structure and, in addition, is organized by the benzyl synthon into a 3D architecture.

Prevalence of chemical defenses among freshwater plants.

Although macrophyte herbivore interactions in freshwater systems were generally disregarded for many years, recent data suggest that herbivory can be intense and important in structuring freshwater communities. This has led to the hypothesis that chemical defenses should be common among freshwater plants, but few studies have reported such chemical defenses, and no previous studies have assessed the frequency of chemical defenses among a substantial number of freshwater plant species. In a study of 21 macrophyte species co-occurring with the omnivorous crayfish Procambarus acutus in a southeastern USA wetland environment, we found that extracts of 11 species (52%) deterred feeding by P. acutus when tested in artificial foods at natural concentrations. Of these 11 chemically defended species, one species, Eupatorium capillifolium, consistently had a more unpalatable extract following mechanical damage to plant tissue, indicative of an activated chemical defense. Because herbivores are commonly nitrogen-limited and select food based on several plant traits, including plant nutritional value, it might be expected that chemical defenses would be especially important for protein-rich plants. However, we found no relationship between soluble protein concentration and deterrence of plant extracts.