The nickel base alloy is nickel-based, adding other metals, such as tungsten, cobalt, titanium, iron and other metals; Nickel ----- EU in 1994 by the 94/27/EC directive (Nickel Release Directive), the direction control of nickel (Ni) (Ni) for use in direct and prolonged contact with the skin on amount. Nickel generally appear in the alloy, as metal accessories, such as buttons, zippers, rivets, metal earrings, necklaces, rings and other apparel products. Some of nickel allergic reaction, if long-term exposure to nickel-containing jewelry, will produce severe irritation to the skin. The release of nickel has been limited by the EC. Weekly emissions does not exceed the number of long-term contact with the skin of the gold-plated or gold-plated products, 0.5ug/CM 2. The bottom of the metal components with piercings such as earrings rod, its weekly emissions can not exceed 0.2ug/cm2. Food sources Containing nickel-rich foods: chocolate, nuts, dried beans and cereals. Metabolic absorption Dietary nickel by intestinal iron operation system through the intestinal mucosa, absorption and operation of the process is not yet clear, the nickel absorption rate of about 3% to 10%, milk, coffee, tea, orange juice, vitamin C, the absorption rate decreased. Increase the absorption rate of iron deficiency, pregnancy and lactation. Nickel absorption of human blood transported to the body through the primary ligand in the serum albumin. Nickel is also combined with the serum of L-histidine and α-macroglobulin. Absorbed into the bloodstream of 60% of the nickel from the urine, the higher nickel content in sweat, bile discharge a lot of nickel. Presence of nickel carbonyl, in some environments, it is colorless and transparent liquid, boiling point 43 ° C, can be vapor form of respiratory rapidly by inhalation, skin can also be a small amount of absorption into the body of nickel carbonyl from about 1/3 in 6 hours by the breath discharge, the rest is absorbed into the bloodstream through the alveoli, the last by the urine. 24 hours after the inhalation of nickel carbonyl body leaving only 17% of all discharged six days. Physiological functions Biochemical function in higher animals and humans in vivo, the nickel is not yet understood. However, the in vitro experiments, animal experiments and clinical observations provide valuable results. 1 In vitro experiments showed affinity for the Ni thiamine pyrophosphate (Auxiliary carboxylase), pyridoxal phosphate, porphyrins, proteins and peptides, and prove nickel in combination with the RNA and DNA. 2 nickel deficiency the intrahepatic six kinds dehydrogenation sensitive decrease in glucose-6 - phosphate dehydrogenase, lactate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase and glutamate dehydrogenase. These enzymes are involved in generating NADH, anaerobic glycolysis, TCA cycle and release nitrogen from amino acids. Nickel deficiency liver cells and mitochondrial structural changes, especially within the network quality is not regular, reduced mitochondrial oxidative function. 3. Decrease in the blood of patients with anemia nickel content, but also reduce the absorption of iron, nickel stimulate hematopoietic function, and animal supplement nickel red blood cells, hemoglobin and white blood cells increase. Physiological need The daily intake of dietary nickel 70 ~ 260μg / d, the requirements are based on the results of animal experiments projected requirement of 25 ~ 35μg / d. Overexpressing Daily intake of soluble nickel 250mg will cause poisoning. Some people are more sensitive to intake of 600μg can cause poisoning. Based on animal experiments, chronic excess intake or excessive exposure can lead to cardiac muscle, brain, lung, liver and kidney degeneration. Nickel deficiency Animal experiments have shown that the lack of nickel may appear slow growth, fecundity weakened. That nickel is a trace element necessary for the human body, nickel-based alloys is another matter! Depends on the nickel-base alloy on the basis of nickel with another what metal music!