An early stage of skin cancer that develops from squamous cells (the flat, scale-like cells in the outer layer of the skin). The hallmark is a persistent, progressive, slightly raised, red, scaly, or crusted plaque that may occur anywhere on the skin surface or on mucosal surfaces, such as in the mouth. Under a microscope, atypical squamous cells are seen to have proliferated through the whole thickness of the epidermis (the outer layer of the skin) but not beyond. Squamous cell carcinoma in situ is commonly caused by sun exposure, but can be from prolonged exposure to arsenic. Also known as Bowen disease.
- Squamous cell carcinoma
Cancer that begins in squamous cells — thin, flat cells that look under the microscope like fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of hollow organs of the body, and the passages of the respiratory and digestive tracts. Squamous cell carcinomas may arise in […]
- Stop codon
A set of three adjacent bases in the DNA or their complementary bases in messenger RNA that specifies the end of a polypeptide chain. The three stop codons (in messenger RNA) are UAA, UAG, and UGA. They are also called termination codons or nonsense codons. U = uracil; A = adenine; G = guanine.
- Storm supplies kit
small canister, ABC type Tube tent Pliers Tape Compass Matches in a waterproof container Aluminum foil Plastic storage containers Signal flare Paper, pencil Needles, thread Medicine dropper Shut-off wrench, to turn off household gas and water Whistle Plastic sheeting Map of the area (for locating shelters) 1 2 Next
- Storm surge
The onshore rush of sea or lake water caused primarily by the high winds that are associated with a landfalling hurricane, typhoon, or tropical cyclone and secondarily by the low pressure of the storm. The term tidal surge is often mis-used to describe storm surge, but a storm surge is independent of the usual tidal […]
A condition in which the visual axes of the eyes are not parallel and the eyes appear to be looking in different directions. In divergent strabismus, or exotropia, the visual axes diverge. In convergent strabismus or esotropia, the visual axes converge. The danger with strabismus is that the brain may come to rely more on […]