Excessive exposure to ultraviolet light, will burn the skin, or cause senile cataracts, and even cause skin cancer and so on. But a moderate amount of ultraviolet light on the human body has many benefits:
Disinfection of human epidermis is distributed in a basal cell, this cell contains "melanin" is a tyrosine substance, in the role of ultraviolet light, "melanin" into black, deposited on the skin by the skin. Under the action of ultraviolet rays, "melaninogen" turns into black color and deposits on the surface of the sunburned skin, making the skin uniformly dark brown. This is an important cause of sun tanning. This pigmentation absorbs more light energy, which is rapidly converted into heat energy and stimulates the secretion of sweat glands to dissipate heat. Sun exposure kills bacteria on the skin and prevents skin diseases such as boils and folliculitis. Indoor sunshine often, sunshine bedding, can reduce the spread of disease.
Promote calcium and phosphorus metabolism of human skin contains steroids, this substance can be changed into vitamin D by ultraviolet irradiation of sunlight. Vitamin D into the bloodstream to improve the metabolism of calcium and phosphorus, anti-rickets, bone softening and osteoporosis in old age.
Enhance the body's immune system UV radiation in the sun can stimulate the body's hematopoietic function, so that the number of red blood cells increased, increased hemoglobin, improve the quality of red blood cells, improve the state of muscle activity, but also reduce blood pressure, blood sugar, cholesterol, increase the body's immune system, promote the body's cellular oxygen uptake capacity and metabolism, alleviate asthma and joint pain, soothe the tendons and activate the blood to enhance the quality of health.
These are the most important things that you can do for your health.
So, what time should you receive UV rays? Summer 11-17 hours should not accept the sun, because this time the infrared is too strong, generally can reach 1.5 calories per minute per cubic meter or more, the resulting temperature is 37 ℃ -45 ℃. Spring and fall season 7-10 o'clock, or 15-16 o'clock, this time, the sun in the ultraviolet light is strong, infrared weak.
UV damage
In the summer heat, the sun's ultraviolet radiation on the human body is difficult to avoid. Excessive exposure to ultraviolet light from the sun can cause damage to the skin, eyes, and immune system. Ultraviolet rays can destroy human skin cells, leading to wrinkles, pigmentation, make the skin before aging, and in severe cases produce solar dermatitis and sunburn, or skin and mucous membranes of solar keratosis, causing cancer. The eye is a sensitive organ of ultraviolet light, ultraviolet light can cause damage to the lens, is one of the causative factors of senile cataract.
In the blazing summer, 10 a.m. to 3 p.m., the sun's ultraviolet intensity is the strongest, outdoor activities should be avoided during this time to avoid ultraviolet damage to the human body, even if you need to be outdoors during this period of time, do not forget to hold an umbrella, wear a sun hat or sunshade mirror, the use of formal manufacturers of skincare and sunscreen, and try to white or light-colored clothes to reduce The first thing you need to do is to get rid of all the UV rays that can cause unnecessary damage to your body.
Although excessive UV rays can cause damage to the human body, UV rays are essential for the healthy growth of the human body. The 7-dehydrocholesterol in the skin is converted to vitamin D3 by light irradiation, and vitamin D3 has an important physiological function in maintaining the concentration of calcium ions inside and outside the cells of the human body and regulating calcium and phosphorus metabolism. In countries with insufficient sunlight, rickets in infants and young children and adult osteomalacia and osteoporosis of the incidence of more than infants can not thrive without an appropriate amount of sunbathing, the human body needs an appropriate amount of ultraviolet light, therefore, an appropriate amount of light is still necessary.
Infrared rays (Infrared rays) are one of the many invisible rays of the sun, discovered by the German scientist H?sschel in 1800, also known as infrared radiation (Infrared radiation). The wavelength of infrared radiation on the solar spectrum is greater than that of visible light, with a wavelength of 0.75 to 1000 μm. Infrared radiation can be divided into three parts, i.e., near-infrared radiation with a wavelength of 0.75 to 1.50 μm; mid-infrared radiation with a wavelength of 1.50 to 6.0 μm; and far-infrared radiation with a wavelength of 6.0 to 1,000 μm. In recent years, due to the improvement of testing equipment and in-depth research, people have a more comprehensive understanding of the physical properties of infrared radiation and its biological effects, and have made a lot of progress. Infrared rays, especially far-infrared rays, have been widely utilized in the health care industry, and a large number of infrared products related to daily life have also appeared. In this paper, the biological effect mechanism of infrared rays and the current status of its clinical applications are introduced.
First, the mechanism of infrared biological effect
Infrared is a kind of electromagnetic wave, when it radiates to the object through the radiation mode, the radiant energy absorbed by the object is transmitted to the object of atoms, molecules and other particles, so that these particles undergo irregular movement, resulting in the warming of the object, known as the primary effect of the infrared rays, also known as the effect of warming. Produce a primary effect at the same time, the object also occurs with other chemical, physical and other changes, which is called the object to absorb far infrared radiation after the secondary effect, also known as the secondary effect.
Infrared radiation on human skin, subcutaneous tissue has a strong penetrating power. The primary effect of external infrared radiation on the human body can make the skin and subcutaneous tissue temperature increase accordingly, promote blood circulation and metabolism, and promote human health[1] . Infrared physiotherapy has been clinically recognized for its thermal, anti-inflammatory and regenerative effects on tissues, and is usually used to directly irradiate lesions. Near infrared micro-irradiation therapy has a significant effect on the improvement of microcirculation, especially the improvement of micro-blood flow status. After irradiation, capillary blood flow is accelerated, erythrocyte aggregation is reduced, and subpapillary venous plexus stagnation is reduced or disappeared, which has a positive effect on the improvement of nutrition, metabolism, repair, and function of tissues and important organs[2].
The mechanism by which infrared light produces secondary effects on the human body is not yet fully understood.
Some scholars believe that far infrared radiation can produce *** vibration effect on cells, mainly caused by the vibration of water molecules inside and outside the cell, so that the cell activation, a series of beneficial to the health of the cell biochemistry and cellular histochemistry changes [1]. It is also believed that the wavelength of 8 ~ 14 microns of far infrared rays can be called "life light", can significantly improve the human microcirculation. It acts on the human body water molecules can be aging in the body of large molecules *** vibration to make it cracked, reassembled into smaller water molecules, in the process, adsorbed on the surface of the aging molecular group of pollutants can be removed, the specific gravity of water rises, water molecules attached to the surface of the cell membrane increases, enhancing the activity of the cells and surface tension. Due to the increase of water molecules penetrating the cell membrane, the activity of intracellular calcium ions is strengthened, which enhances the normal function of human cells and improves bactericidal ability and immunity. In addition, life light can also make the blood unsaturated fatty acid double or triple bond is cut off, saturated fatty acid is not easy to be oxidized into lipids [lipid peroxide], reducing the deposition of lipids in the blood vessels, make the blood vessel wall smooth, thus reducing atherosclerosis, cataracts and other cardiovascular diseases or ophthalmic diseases, on the human body health plays a good role in the promotion of efficacy [3].
Pang Xiaofeng studied the mechanism and characteristics of biological energy transfer released by hydrolysis of ATP molecules, and concluded that infrared radiation has biological effects on living beings (including human beings) and medical functions mainly come from the non-thermal biological effects of infrared radiation. 1-7μm infrared radiation can be transmitted through the skin to the cells, and is absorbed by protein molecules. Protein molecules can and can only absorb or emit infrared light with wavelengths of 1-3.5μm and 5-7μm, and the absorption of infrared light of this range of wavelengths can lead to the quantum vibration of amide bonds in the protein molecules, which can make the bio-energy be smoothly transferred from one place to another, so that the living organisms are in a normal state, and the growth, development and health of the living organisms can be maintained. The bioenergy to maintain the normal functioning of the living system is provided by the hydrolysis of ATP. However, if there is insufficient ATP molecules or ATPase (the hydrolysis of ATP requires the participation of enzymes) or water, or if there is a change in the structure or conformation of proteins or aberrations, etc., the amount of bioenergy provided is insufficient to cause the normal vibration of the amide bond or the transfer of bioenergy cannot take place normally. When biological tissues do not receive enough energy, they cannot grow normally and various diseases are induced. In this case, if the infrared radiation with the above wavelength can be irradiated and absorbed by proteins, the protein molecules can be restored to normal and the bioenergy can be transmitted normally, which may restore the biological tissues from the state of sickness to the normal state and make the diseases cured. In the infrared medical instrument clinical trials have also proved that the infrared ray has a certain medical effect on the organism or human is also exactly in this wavelength range, that is, 0.8 ~ 1.6 μm and 4.8 ~ 7 μm [4].
The study of the effect of infrared radiation on the immune function of the body is still in its infancy, and the mid-wave infrared radiation is more likely to act on the immune cells in various wavelengths and promote their biological functions. The effect of infrared radiation is not only related to its wavelength, but also related to the number of photons emitted, that is, related to the intensity and duration of radiation, excessive infrared radiation may also cause adverse effects on the body, the detailed mechanism needs to be further elucidated. Cao Zhiran et al. concluded that infrared radiation has both indirect and direct effects on the immune system. Indirect effect means that infrared radiation can regulate the state of other systems such as the nervous system and endocrine system, so as to achieve the purpose of regulating the immune system. The direct effect refers to the fact that infrared radiation absorbed by the body can enhance the biological field around immune cells and immune organs, so as to increase their activity and inter-regulation. Infrared photons can directly act on the stimulation points of immune cells, which include the receptors on the surface of immune cells (such as PHA-R, TCR, L-2R, etc. on the surface of T-cells) and enzymes, thus activating the cells, and causing them to proliferate and differentiate [5 The cell proliferation and differentiation will result from the activation of the cells [5]. Mao et al. hypothesized that the mechanism of action is that infrared rays may activate the deep tissue receptors, and its physiological and biochemical effects on the one hand, through the neurohumoral reflex pathway, and on the other hand, may be through the meridian conduction pathway, which is not well understood, and positively affects the activities of biological macromolecules, cells, and organs, thus having an overall benign effect [2].
Second, infrared radiation on the human body may cause adverse effects
Thermal radiation, also known as infrared radiation, iron and steel metallurgical enterprises in the high temperature operating environment is mainly characterized by strong thermal radiation high temperature. Especially in the iron and steel smelting, red steel hot rolling and medium-sized sintering machine, is a typical infrared thermal radiation contact operations. Wavelength 0.8 ~ 1.2 μm of short-wave infrared radiation can pass through the cornea into the eye, the aqueous humor, iris, lens and vitreous fluid absorption of a portion of infrared rays and lead to cataracts, known as "infrared cataracts", at home and abroad are the first to be seen in the glass workers, iron and steel smelting workers. Cao Duozhi et al. found that the iron metallurgy furnace operation thermal radiation hazard is still very serious, with the increase in the working age of the operation of the vision has a significant trend of decline, the detection rate of crystal clouding reached 9.46%, and found that with the distance from the heat source and the age of the post related to the work [6]. Some studies have also pointed out that ultraviolet (UVR) and infrared (IFR) damage to the eye and skin is an important aspect of the occupational damage of welding operations, welding operations of ultraviolet and infrared can cause corneal and crystal damage [7].
Infrared light from the sun has a different effect on the skin than ultraviolet light. While UV rays cause photochemical and photoimmune reactions, infrared radiation produces reactions due to molecular vibrations and increased temperature. The thermal radiation caused by infrared rays penetrates the skin more than UV rays. Between 25% and 65% of the radiation reaches the epidermis and dermis, and between 8% and 17% reaches the subcutaneous tissue. Infrared radiation through its thermal radiation effect makes the skin temperature rise, capillary dilation, congestion, increased epidermal water evaporation and other direct adverse effects on the skin. The main symptoms are red papules, premature aging of the skin and pigmentation disorders. Increased skin temperature, capillary dilation and congestion, increased epidermal water evaporation and other direct adverse effects on the skin.
Infrared rays also enhance the damaging effects of UV rays on the skin, accelerating the skin aging process. Using the same sunscreen products and the same energy of UV intensity, in the outdoor natural sunlight measured SPF value (sun protection factor) is significantly lower than in the laboratory artificial light measured by the effectiveness of sunscreen, which is due to the natural sunlight, the skin is subject to UV and infrared radiation caused by the dual role of the cause. Infrared and UV rays play the same role in accelerating tissue degeneration. Infrared light also promotes the development of UV-induced skin cancer [8].
Third, the clinical application of infrared biological effects
Infrared rays can be absorbed by the superficial tissues of the body surface, has a significant drying and dehydrating effect, so that the local blood circulation of the tissues is accelerated, and anti-inflammatory and analgesic effects. Clinical use of local external safflower oil and far-infrared irradiation to treat decubitus ulcers has been found to be effective and fast[9]. The use of far infrared radiation for the treatment of herpes zoster, the results of pain, blisters and dementia time are shorter than the control group [10]. Experiments have shown that the far-infrared rays of bioceramics have a significant therapeutic effect on the treatment of burns. For the treatment of injury pain, chronic soft tissue injury has the best efficacy[11]. Clinical care observation found that in the traditional textile materials added to the ultra-fine ceramic particles made of far-infrared protective gear, such as waist, knee, elbow, wrist, neck, etc., in the anti-inflammatory, swelling, blood circulation, pain, through the meridians and improve microcirculation has a significant effect. It is more effective than magnesium sulfate wet hot compress, hot water bag hot compress and drug closure, and at the same time, it can avoid the pain caused by closure to the patient[12]. In the past, neonatal red buttocks and ulcers were mostly prevented and treated by washing with disinfectant drugs and keeping them dry, which had poor therapeutic effect and was easy to recur. Far infrared radiation heating beds were used to treat children with red buttocks and buttock ulcers, and the average healing time of the treatment group was shortened and the effective rate was higher compared with that of the control group [13]. Neonatal scleroderma in the treatment of rewarming is an important part of the success of the treatment, in the past the use of ordinary warming box gradually rewarming effect is poor, now the use of far-infrared rapid rewarming of the child's morbidity and mortality decreased significantly, the success rate of resuscitation significantly improved [14].
Flap necrosis is a common postoperative complication in plastic surgery, mainly due to microcirculatory disorders, for which there is no ideal prevention and treatment. Jiang et al. investigated the effect of far-infrared rays in the wavelength range of 2.5-15 μm on the survival of skin flaps by directly observing the microcirculatory changes of random skin flaps on the back of rats in vivo. It was found that localized far-infrared radiation had a biological effect similar to that of vasodilators, and could improve microcirculation and increase the survival rate of skin flaps without obvious side effects within the range of therapeutic doses[15].
A Japanese scholar reported that the use of linearly polarized infrared light in the treatment of various types of pemphigus vulgaris had significant efficacy [16].
Linearly polarized near infrared light is used for the treatment of temporomandibular joint pain caused by rheumatoid arthritis with a short treatment course and good efficacy [17]. Compared with the traditional local nerve block treatment, although the number of treatments in the near-infrared group is more than that in the traditional nerve block group, the treatment range is wide, the pain caused by local nerve block treatment can be avoided, and the efficacy is high, and the effect is long-lasting and not easy to recur. The mechanism may be that light plays a photoelectric stimulation, electromagnetic wave effect and photochemical effect, which can inhibit nerve excitation, relax muscles, relax blood vessels, increase blood flow, promote lymphatic circulation, promote the production of active factors, thus playing a therapeutic role [18].
Some people have observed the blood viscosity of 66 cases of cardiovascular and cerebrovascular patients before and after low-temperature stimulation of far-infrared radiation therapy, and found that low-temperature stimulation of far-infrared radiation has a low-temperature thermal power effect of a wide range of biological effects, which can reduce the blood viscosity of patients with cardiovascular and cerebrovascular diseases, prevent thrombosis, improve microcirculation, reduce chest tightness, palpitations, dizziness, numbness and other symptoms [19].
Near-infrared therapy has a certain regulatory effect on the immune function of patients with CAH, patients with SG, IgG, γ-globulin decreased, ANA, RF negative, SA, CH50, C3 increased, humoral immunity has a tendency to normalize[20]. Infrared radiation can also promote the role of Con-A induced production of L-2, significantly increase the ADCC effect of rat splenocytes, so that the conversion rate of PHA-stimulated T-lymphocytes in mice increased, the splenic index increased, increase the number of lymphocytes in the peripheral blood and the number of splenic macrophages [5], also has a good effect on the body's free radical metabolism and the activity of N K-cells [2].
The use of infrared irradiation of the bladder area in the treatment of urinary retention is painless for the mother, does not increase the amount of postpartum hemorrhage, and is easily accepted by the mother compared with other drug therapies. After the infrared ray acts on the skin, the absorbed energy is converted into heat energy causing the skin temperature to rise, stimulating the heat receptors in the skin, relaxing the vascular smooth muscle through the thalamus reflex, dilating the blood vessels, strengthening the blood circulation, promoting the absorption of exudate, facilitating the inflammation and swelling to subside, and alleviating the tension and spasm of the muscles, so that the effect of the treatment of urinary retention is obvious [21].
Gai Qifeng et al. used far infrared irradiation with wavelength of 2～25μm to irradiate the pressure and pain area of the lower abdomen (including Qihai, Guanyuan, and Belt Pulse points) to treat pelvic inflammatory masses. 62 patients, all of whom were diagnosed by obstetrics and gynecology and ultrasonography, all of them had lower abdominal pain and pressure, and all of them had palpated cystic masses on gynecological examination, and were cured with an apparent efficacy rate of 88.6%, and the overall effective rate was 96.6%. The use of far-infrared irradiation for the treatment of pelvic inflammatory masses can increase the local microcirculation, enhance the ability of leukocytes to travel and phagocytosis, and promote the absorption of inflammation[22].
Some people use far-infrared irradiation to treat 208 cases of pediatric intestinal spasm, and found that its efficacy is significantly better than drug therapy, and simple and easy to implement, no side effects, children are happy to accept [23].
Infrared radiation on diabetic rabbit hyperglycemia has obvious alleviating effect, its metabolic regulation mechanism for the inhibition of cyclic nucleotide cyclase (AC) activity at the same time activate the phosphodiesterase (PDE) activity, so that cyclic adenosine monophosphate (cAMP) synthesis is blocked and hydrolysis is accelerated, the cAMP level decreases, and then reduce the blood glucose[24].
Some people explored the effect of far infrared light on endogenous opiates in the brain of S180 rats through in vivo experiments, and found that the content of β-endorphin and leucine enkephalin increased significantly in the brain of each group treated with far infrared light. The enkephalinergic interneurons are believed to form axial-axial synapses with the nociceptive afferent axons, which can produce potent pain-suppressing effects. This provides a theoretical basis for the clinical application of mid- and far-infrared rays to treat and alleviate pain in tumor patients and relieve herpes zoster and limb pain[25].
In many disease states, excessive production of reactive oxygen species (ROS) or reduced activity of antioxidant enzymes can cause lipid peroxidation damage to cell membranes, leading to cell death. It has been shown that tumor hosts have a reduced ability to scavenge free radicals, suggesting that the antioxidant enzymes of natural antioxidants are insufficient. Teng Yanjie et al. investigated the changes in free radical metabolism in the liver of tumor-bearing rats through in vivo experiments. They found that the activities of liver SOD and GSH-Px were significantly increased and the content of MDA was significantly decreased by the application of mid- and far-infrared light therapy, and MDA is a double-bonded fatty acid peroxidation product, and the content of MDA reflects the concentration of lipid peroxides. The MDA is a double-bonded fatty acid peroxidation product, and its content reflects the concentration of lipid peroxides. The MDA content of liver tissue of rats with tumors was significantly reduced, and the activities of liver SOD and GSH-Px were significantly increased due to the activation of cells by the mid- and far-infrared rays, which led to the enhancement of the ability of the tumor hosts to scavenge free radicals, and the inhibition of the growth and proliferation of tumor cells [26].
Trace elements play a very important role in the biochemical processes in the body. As an important part of many substances in the body, they have a close relationship with growth and development, cardiovascular and cerebrovascular diseases, immune function, and aging, etc. However, there is no definite treatment for the excess or decrease of trace elements caused by various diseases. Wang Jianjie et al. studied the effect of irradiation of general-purpose broad-spectrum therapeutic instrument on trace elements in the liver of mice, and found that the peak wavelength of 7-10 μm in the far-infrared irradiation of the imbalance of trace elements can be adjusted bi-directionally, and for the normal content of the normal content can be promoted absorption, and play a very good role in the prevention of disease, treatment of disease, health care [27].