Hair composition

Anomalously high Ca concentrations in hair samples (up to 8285 (xgg-1) which correlate with high P concentrations (up to 4720 jxg g-1) from a group of women from Rio de Janeiro were detected by ICP-MS measurements.87 These abnormal hair compositions were related to endocrinological pathologies affecting calcium/bone metabolism. Very low Ca concentrations were observed in older women and were related to senile osteoporosis.87... 

Kist AA, Zhuk LI, Danilova EA, et al. 1998. Mapping of ecologically unfavorable territories based on human hair composition. Biol Trace Elem Res 64 1-12. 

Polyurethanes containing polytetrahydrofuran, diethylene glycol, stearyl alcohol, and hexamethylene diisocyanate were prepared by Meffert [1] and used in hair compositions. 

Shapiro, I., Dado, G., Allen, D. and Sajic, B. (2008) Rinse-out skin/hair composition, e.g. shampoo, body wash, facial cleanser comprises acyl lactylate containing lactyhc acid, non cationic surfactant, and water. Patent Nos W02007100784-A2 W02007100784-A3. 

Chemistry produces many materials, other than drugs, that have to be optimized in their properties and preparation. Chemoinformatics methods will be used more and more for the elucidation and modeling of the relationships between chemical structure, or chemical composition, and many physical and chemical properties, be they nonlinear optical properties, adhesive power, conversion of light into electrical energy, detergent properties, hair-coloring suitabHty, or whatever. 

Hair Coloring Regulation Issues. In the United States the classification of color additives is complex. Under the Federal Food, Dmg and Cosmetic Act, all cosmetic colors must be the subject of an approved color additive petition to the Food and Dmg Administration there is an exception for coal-tar colorants used to color hair. Based on the composition of these colorants, FDA can require a certification on each manufactured batch of colorant to assure conformance with the approved specifications. In the early 1990s FDA has required certification only for synthetically derived coal-tar type colors. Many of the approved color additives, both certified and noncertified, are restricted ia their potential use. These restrictions can be found ia the color additive regulations ia the Code of Federal Regulations at 21 CFR 73 and 74. 

Hair straightening compositions based on mixtures of ammonium bisulfite [10192-30-0] and urea [57-13-6] have been introduced and have found some apphcation in the Caucasian hair market. The reformulation of the cystine cross-links in bisulfite-reduced hair is best accompHshed by a rinse, pH 8—10, rather than by the use of oxidizing agents (66). 

Compositions have been pubHshed for cream tinses (82), hair conditioners, dressiags, and mousses (83), hair-styling products (84), hair sprays (85), hair colorants (86), hair-waving products (87), hair-straightening products (88), and depilatories (89). 

The word "composites" has a modern ring. But using the high strength of fibres to stiffen and strengthen a cheap matrix material is probably older than the wheel. The Processional Way in ancient Babylon, one of the lesser wonders of the ancient world, was made of bitumen reinforced with plaited straw. Straw and horse hair have been used to reinforce mud bricks (improving their fracture toughness) for at least 5000 years. Paper is a composite so is concrete both were known to the Romans. And almost all natural materials which must bear load - wood, bone, muscle - are composites. 

The essential genetic material ofthe original vegetative bacterium is retained in the core or protoplast around this lies the thick cortex which contains the murein or peptidoglycan already encountered as a cell wall component (see Fig. 1.2). The outer coats which are protein in composition are distinguished by their high cysteine content. In this respect they resemble keratin, the protein of hair and horn. 

The hair fibers derived from furry mammals are mainly made up (over 80%) of the structural protein keratin. The distinction between wool and hair is not compositional, but related to size wool fibers are generally fine and short, whereas those of hair are usually thicker and longer. The molecule of keratin consists essentially of a combination of amino acids about 18 amino acids make up the keratin molecule (see Textbox 67). The nature of the amino acids, their relative amounts, and their sequence and arrangement within the molecule of keratin vary from one animal species to another but are characteristic of any variety of wool or hair (Asquith 1977) (see Table 89). 

The isotopic composition of carbon in the proteins, which are one of the main components of animal tissues, reflects the nature of the food resources in the diet of the animals. Determining the relative abundance of the stable isotopes of carbon in the proteins of bones or hair, for example, can facilitate understanding of the effects that different types of plants or animal food resources had on ancient diets (Katzenberg 2000 Burton 1996). 

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