41. "' Pentalene "'is a polycyclic hydrocarbon composed of two fused cyclopentadiene rings. 42. It is a member of the unsaturated polycyclic hydrocarbons class of compounds and a tetramer of benzyne. 43. One study showed that the reaction lends itself to cascade reactions to form more complex polycyclic aromatic hydrocarbons 44. The disease is polycyclic in nature even though the conidia are not as virulent as the ascospores. 45. Upon infection the pathogen continues to produce conidia throughout the season resulting in a polycyclic disease cycle. 46. :Wisps of red in the cloud are organic molecules called polycyclic aromatic hydrocarbons ( PAHs ). 47. Significant research on polycyclic musks and nitromusks has taken place since the 1990s in biomonitoring studies,. 48. His scope extends further to polycyclic heterocycles and the total synthesis of ( + )-aphanorphine. 49. "' Octalene "'is a polycyclic hydrocarbon composed of two fused cyclooctatetraene rings. 50. "' Phenanthrenedione "'is a cytotoxic derivative of the polycyclic aromatic hydrocarbon phenanthrene.
