Swelling of hair

Recently Swift [120] and others have provided evidence that the nonkeratin portions of hair are also important to fiber swelling. For example. Swift demonstrated by the penetration of fluorescent-labeled proteins in water that a large-order swelling occurs in the nonkeratin regions of hair. The diametral swelling of hair by water from the dry state is about 14 to 16%. On the other hand. X-ray diffraction measurement of inter-intermediate filament separation distances indicates that swelling of only 5.5% occurs... 

Because reduction of the disulfide bond and its subsequent reactions is vital to several important cosmetic products, a large amount of research that is relevant to these chemical processes has been conducted. This chapter is concerned with reducing the disulfide bond in hair by mercaptans, sulfites, alkalis, and other reducing agents. Reactions of reduced hair are also considered, followed by a discussion of water setting, set and supercontraction, and swelling of hair, processes especially relevant to permanent waves, hair straighteners, and depilatories. 

Antithyroid drags have several side effects. The most frequent side effects are maculopapular rashes, pruritus, urticaria, fever, arthralgia and swelling of the joints. They occur in 1-5% of patients [1, 2]. Loss of scalp hair, gastrointestinal problems, elevations of bone isoenzyme of alkaline phosphatase and abnormalities of taste and smell are less common. The incidence of all these untoward reactions is similar with MMI and PTU. Side effects of MMI are dose-related, whereas those of PTU are less clearly related to dose [1]. PTU may cause slight transient increases of serum aminotransferase and y-glutamyl transpeptidase concentrations but also severe hq atotoxicity whereas methimazole or carbimazole can be associated with cholestasis. The side... 

Tinea capitis Infection of the head and scalp May be asymptomatic initially, then progress to inflammatory alopecia "Black dot" alopecia may develop due to breakage of hair at the root May form kerions (nodular swellings) Scaling or favus may develop on scalp Cervical lymphadenopathy is common Primarily found in infants, children, and young adolescents, often in African-American and Flispanic populations Can be spread from person to person or animal to person... 

In an alkaline solution, the cuticle—the outermost layer of a strand of hair—swells up, softens, and becomes rougher. The cuticle is made up of translucent, flattened cells that line the hair shaft like shingles on a roof. The cuticle gets rougher when the cells do not lay flat. When the raised cuticle cells of one piece of hair get stuck on the raised cuticle cells of another piece of hair, the hair tangles. The raised cells also reflect light differently than smooth, flat cells, making the hair appear dull. 

I looked at him. Then he knelt, and uncovered his head. His hair had dried dark gold, and where his neck was bowed I could see the swell of muscles under his fine, fair skin, and the dark, puckered line of a sword-scratch, and the gleam of fresh sweat along the cords of his neck. The desire that I had long denied turned in my belly, so quick and hot that I thought he must feel it through the heavy air that lay between us. 

Dehairing is carried out using alkaline proteases such as subtilisin in a very alkaline bath. Alkaline conditions tend to swell the hair roots, so easing the removal of the hair by allowing the proteases to selectively attack protein in the hair follicle. Other specific enzymes are used for skins from particular species. 

A dye is considered permanent if it penetrates into the hollow hair shaft. Coloring of hair starts with a treatment of substances such as hydrogen peroxide and ammonia. The ammonia causes hair shafts to swell and open, allowing dye intermediates and couplers to penetrate. Dyes applied during the second step of coloring react with the precursors to form pigments that remain in the hair. 

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