Melanoma, a type of cancer that develops in melanocytes, is usually caused by direct exposure of skin to ultraviolet (UV) radiation resulting in cellular damage. In this study, a procedure to determine the effects of various commercial sunscreens with SPF values ranging from 15 to 100 was developed using pig skin to mimic human skin. These…

Proficiency with instrumental analysis via GC-MS is an important skill for chemistry students. The application of analytical techniques and fundamental theoretical principles to real-world problems can be valuable learning exercises for undergraduates which can also improve their analytical thinking skills. Xylitol is generally considered safe for…

A laboratory experiment is described that extracts the tetrapyrrolic teal-colored biliverdin IXa, as its dimethyl ester, from commercially available emu eggshells. The extraction of ~10 mg samples of biliverdin is simple and requires two 3 h lab periods: A two-step acid digestion and liquid-liquid extraction, followed by short silica gel flash…

Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

Mercury is a known neurotoxin that is particularly harmful to children and unborn fetuses. Consumption of contaminated fish is one major route of mercury exposure. This laboratory experiment gives students an opportunity to measure mercury concentrations in store-bought seafood and compare the results to suggested exposure limits. The U.S.…

Memory deficits produced by marijuana arise partly via interaction of the psychoactive component, [Deta][superscript 9]-tetrahydrocannabinol ([Deta][superscript 9]-THC), with cannabinoid receptors in the hippocampus. Although cannabinoids acutely reduce glutamate release and block hippocampal long-term potentiation (LTP), a potential substrate for…

The neural pathways that convey conditioned stimulus (CS) information to the cerebellum during eyeblink conditioning have not been fully delineated. It is well established that pontine mossy fiber inputs to the cerebellum convey CS-related stimulation for different sensory modalities (e.g., auditory, visual, tactile). Less is known about the…

An experiment is conducted to ascertain trace-level Pb in samples of bovine liver or muscle by applying graphite furnace atomic absorption spectrophotometry (GFAAS). The primary objective is to display the effects of physical and spectral intrusions in determining trace elements, and project the usual methods employed to minimize accuracy errors…

We investigated the influence of the protein synthesis blocker anisomycin on contextual memory in the terrestrial snail "Helix." Prior to the training session, the behavioral responses in two contexts were similar. Two days after a session of electric shocks (5 d) in one context only, the context conditioning was observed as the significant…