While it is now universally accepted that Ramsay Hunt syndrome is caused by varicella-zoster virus, Bell's palsy continues to be labeled "idiopathic." We review the literature associating Bell's palsy with various infectious agents as well as with Kawasaki disease, a condition in which an infectious etiology is suspected. Good evidence--mostly serological--exists for an etiologic role for the herpes group of viruses, mumps virus, and rubella virus. In addition, recent evidence has focused on Bell's palsy in human immunodeficiency virus infection and Lyme borreliosis. In view of the multiplicity of implicated agents, it is likely that the immunologic response associated with infection triggers a cranial or generalized polyneuropathy culminating in facial nerve compression, degeneration, and paralysis. The mounting interest in Bell's palsy, coupled with the increasing availability of more sensitive and specific tests, is likely to augment the available evidence for an infectious etiology and to clarify the role of other, previously unsuspected infectious agents.
Biodiesels (fatty
acid methyl esters) derived from oleaginous microbes
(microalgae, yeast, and bacteria) are being actively pursued as potential
renewable substitutes for petroleum diesel. Here, we report the engine
performance characteristics of biodiesel produced from a microalgae
(Chaetoceros gracilis), a yeast (Cryptococcus
curvatus), and a bacteria (Rhodococcus
opacus) in a two-cylinder diesel engine outfitted with an
eddy current brake dynamometer, comparing the fuel performance to
petroleum diesel (#2) and commercial biodiesel from soybeans. Key
physical and chemical properties, including heating value, viscosity,
density, and cetane index, for each of the microbial-derived biofuels
were found to compare favorably to those of soybean biodiesel. Likewise,
the horsepower, torque, and brake specific fuel consumption across
a range of engine speeds also compared favorably to values determined
for soybean biodiesel. Analysis of exhaust emissions (hydrocarbon,
CO, CO2, O2, and NO
x
) revealed that all biofuels produced significantly less CO and hydrocarbon
than petroleum diesel. Surprisingly, microalgae biodiesel was found
to have the lowest NO
x
output, even lower
than petroleum diesel. The results are discussed in the context of
the fatty acid composition of the fuels and the technical viability
of microbial biofuels as replacements for petroleum diesel.
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