Phototoxicity evoked by alpha‐terthienyl
Phototoxicity evoked by alpha‐terthienyl
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DOI：
10.1111/j.1600-0536.1977.tb03656.x
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发表时间：
1977-08
影响因子：
5.5
通讯作者：
Gwendolyn;F. Chan;M. Prihoda;G. Towers;J. Mitchell
中科院分区：
文献类型：
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作者：
Gwendolyn;F. Chan;M. Prihoda;G. Towers;J. Mitchell
过水尿素O=C-NHz·H202是尿素和H202的易分解添加剂化合物。在相对湿度高于40%、温度高于30°C或在皮肤表面普遍存在的条件下，它分解生成尿素和HZ02。过氧化氢通过新生状态下的氧气以两种方式影响头发：(1)将黑色素氧化成无色化合物（Eckardt 1969）(2)氧化分解胱氨酸并形成半胱氨酸。胱氨酸占头发角蛋白氨基酸的20%，这一事实解释了观察到的毛干损伤和冷波烫液的无效，因为头发角蛋白的大部分二硫桥被破坏了（Braun 1963, Orfanos & Ruska 1970, Orfanos & Mahrle 1971）。
Carbamide perhydrate O=C-NHz· H202 is an easily decomposing additive compound of urea and H202. It decomposes to give urea and HZ02 at relative humidities above 40 %, at temperatures above 30°C or under the conditions prevailing on the skin surface. Hydrogen peroxide affects the hair in two ways through its oxygen in a nascent state: (1) Oxidation of the melanin into colourless compounds (Eckardt 1969) (2) Oxidation and decomposition of cystine and formation of cysteinic acid. The fact that cystine accounts for 20 % of the amino acids of the hair keratin explains the damage to the hair shaft observed and the ineffectiveness of cold wave perm solutions, because a majority of the disulphide bridges of the hair keratin are destroyed (Braun 1963, Orfanos & Ruska 1970, Orfanos & Mahrle 1971).