What Is Manganese?
Manganese, the chemical symbol is Mn, and its atomic number is 25. It is an off-white, hard, brittle, and shiny transition metal. Pure metal manganese is a slightly softer metal than iron. Manganese with a small amount of impurities is firm and brittle and wet Oxidation everywhere. [1] Manganese is widely present in nature. The soil contains 0.25% of manganese, and tea, wheat and hard-shell fruits contain more manganese. Manganese-exposed operations include crushed stone, mining, electric welding, production of dry batteries, and dye industry. In 1774, Gann separated manganese metal. Bergman named it manganese. Manganese can be prepared by reducing amanganese with aluminothermic method. The entry introduces the discovery history of manganese, the development status at home and abroad, physical and chemical properties, preparation methods, application fields, distribution and safety measures, etc.
- In the iron and steel industry, it is mainly used for desulfurization and deoxidation of steel; it is also used as an additive to alloys to improve the strength, hardness, elastic limit, wear resistance and corrosion resistance of steel; also used in high alloy steel As austenitic compounding element, it is used to make stainless steel, special alloy steel, stainless steel electrode, etc. In addition, it is also used in non-ferrous metals, chemicals, medicine, food, analysis and scientific research. [1]
- As of the end of 2007,
Manganese Psychiatry
- Manganese ore
- Physiological function
- 1. Can promote bone growth and development.
- 2. Protects the integrity of mitochondria in cells.
- 3 Maintain normal brain function.
- 4 Maintain normal glucose and fat metabolism.
- 5. Can improve the body's hematopoietic function.
- affect health
- Symptoms of manganese deficiency can affect reproductive capacity, may cause congenital malformations in offspring, abnormal bone and cartilage formation, and impaired glucose tolerance. In addition, a lack of manganese can cause neurasthenia syndrome and affect mental development. Manganese deficiency will also lead to reduced insulin synthesis and secretion, affecting glucose metabolism.
- Easily absorbed by the wet mucosal surface to generate sulfurous acid and sulfuric acid. It has a strong stimulating effect on the eyes and respiratory mucosa. Large inhalation can cause pulmonary edema, throat edema, vocal cord spasm and suffocation.
- When mild poisoning occurs, tears, photophobia, cough, sore throat, and sore throat; severe poisoning can cause pulmonary edema within hours; extremely high concentrations of inhalation can cause reflex glottic spasm and suffocation. Inflammation or burns on skin or eye contact. Chronic effects: long-term low-level exposure may have systemic symptoms such as headache, dizziness, and fatigue, as well as chronic rhinitis, sore throat, bronchitis, and decreased smell and taste. A small number of workers have tooth erosion.
- Food intake
- The safe and adequate daily intake of manganese is shown in the following table:
- Manganese soil
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- Food source
- The main food sources of manganese are: walnuts, barley, red molasses, lettuce, dried beans, peanuts, potatoes, soybeans, sunflower seeds, wheat, barley, and liver.
Manganese Nutrition
- Introduction
- Manganese is widely distributed in the biosphere, but its content is very small in humans. The total amount of manganese in adults is about 200-400umol, which is distributed in various tissues and fluids of the body. The concentrations of manganese in bone, liver, pancreas and kidney are higher; the concentrations of manganese in brain, heart, lung and muscle are lower than 20nmol / g; the concentrations of manganese in whole blood and serum are 200nmol / L and 20nmol / L respectively. The concentration of manganese in the mitochondria is higher than that in the cytoplasm or other organelles, so the tissue with many mitochondria has a higher manganese concentration. Manganese was known to be a component of animal tissues in 1913, but manganese deficiency was found in various experimental animals only in 1931, thus confirming that manganese is one of the essential trace elements for animals.
- Food source
- Cereals, nuts, and leafy vegetables are rich in manganese. Manganese is the most abundant in tea. Refined cereals, meat, fish, and milk contain less manganese. Although animal-based foods are not high in content, they have high absorption and retention, and still do not lose a good source of manganese.
- Metabolic absorption
- All small intestines can absorb manganese. The absorption of manganese is a rapid and saturable process, which is likely to be accomplished by a high-affinity, low-volume active transport system and an unsaturated simple diffusion effect. The absorption mechanism of manganese may include two steps. First, it is taken from the intestinal cavity, and then it is transported across the mucosal cells. The two dynamic processes occur simultaneously. During the absorption process, manganese, iron and cobalt compete for the same absorption site. Any high amount of the three will inhibit the absorption of the other two. Manganese is excreted almost completely through the intestine, with only a small amount excreted in the urine. Absorbed manganese is excreted very quickly through the intestines.
- Physiological function
- Part of manganese in the body acts as a component of metalloenzymes, and part of it acts as an enzyme activator.
- Physiological needs
- The appropriate intake of manganese for adults is 3.5 mg / d, and the maximum tolerable intake is 10 mg / d.
- Overperformance
- It has been reported that manganese poisoning is found in patients with impaired liver function, biliary tract obstruction, or both. The patient's brain MRI examination showed obvious abnormalities, and the abnormalities improved with the reduction of poisoning. In addition, although there is no certain conclusion on the issue of oral toxicity, there have been some reports suggesting that this issue deserves full attention and research. For example, it has been found that manganese concentrations in the brain of neurological dysfunction are higher than normal; people with violent behaviors find that manganese is higher than normal.
- Manganese deficiency
- It has been suggested that manganese deficiency may be a potential nutrition problem for humans [12] . Manganese deficiency may also be associated with certain diseases. It has been reported that patients with osteoporosis, diabetes, atherosclerosis, epilepsy, and poor wound healing suffer from low dietary manganese intake, low blood manganese, and low tissue manganese.
- China and even the world s largest manganese reserves are in Xialei Town, Daxin County, Guangxi.