The velocity of sound in gases was measured, using an ultrasonic
wave train as a diffraction grating. The fundamental problems
involved in the optical technique are discussed. An apparatus utilizing
an objective lens of focal length 1.5 m and aperture f/20 was constructed
and used at an ultrasonic frequency close...
Pactamycin, first reported in 1962, is a potent antitumor antibiotic produced by the soil bacterium Streptomyces pactum. Structurally, it contains a cyclopentitol core unit, a 3-aminoacetophenone (3AAP), a 6-methylsalicylic acid (6-MSA), and a N,N-dimethyl urea. The aminocyclopentitol ring is derived from glucose, possibly via N-acetyl glucosamine (GlcNAc), the 3-aminoacetophenone (3AAP)...
Synthesis and discovery lies at the core of every field in chemistry. The investigation of the structure-property relationships in compounds known or new is the fundamental purpose of solid state chemistry. Mixing related solid state compounds to form solid solutions can lead to exciting new and/or unexpected properties. Layered compounds...
Oxidative stress is recognized as an important underlying factor in the
pathogenesis of many degenerative diseases as well as normal senescence. The
free radicals, reactive oxygen species (ROS) and electrophiles produced during
oxidative stress are capable of modifying nucleic acids, lipids and proteins. There
are a variety of oxidative modifications...
The adduction of proteins and other biomolecules by electrophilic lipid peroxidation products such as 4-hydroxy-2-nonenal (HNE), 4-oxo-2-nonenal (ONE), malondialdehyde (MDA) or acrolein (ACR) is thought to be an initiating and/or propagating factor in the pathophysiology of several diseases such as atherosclerosis, diabetes, Alzheimer's, Parkinson's and other age-related disorders. The identification...
Aqueous film forming foams (AFFFs) are proprietary mixtures containing hydrocarbon surfactants and per-and polyfluoroalkyl substances (PFASs) that are used to extinguish hydrocarbon-based fuel fires. There is limited information on hydrocarbon surfactants in AFFFs and AFFF-contaminated groundwater even though they are more abundant (5-10% w/w) than PFASs (0.9-1.5% w /w) in...