Excessive exposure to ultraviolet light can burn the skin, or cause senile cataracts, and even cause skin cancer. But the right amount of ultraviolet light on the human body has many benefits:
Bactericidal disinfection of the human epidermis is distributed in a kind of basal cells, this kind of cell contains "melanin" is a tyrosine substance, in the role of ultraviolet light, "melanin" into the black, and deposited in the sun. Under the action of ultraviolet rays, "melaninogen" becomes black and deposits on the surface of the sunburned skin, making the skin a uniform dark brown color. This is an important reason for sun tanning. This kind of pigmentation can absorb more light energy, quickly transformed into heat energy, and stimulate the secretion of sweat glands and heat dissipation. Sun exposure can kill bacteria on the skin and prevent boils, folliculitis and other skin diseases. Indoor often into the sunshine, diligent sun bedding, can reduce the spread of disease.
Promoting calcium and phosphorus metabolism of human skin contains steroids, this material by the sun's ultraviolet radiation can be changed into vitamin D. Vitamin D into the blood to improve the metabolism of calcium and phosphorus, anti-rickets, osteomalacia and osteoporosis in the elderly role.
Enhancement of 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, the increase in 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, to promote the body's cellular oxygen uptake capacity and metabolism, to alleviate asthma and joint pain, soothing and revitalizing the blood and enhance the quality of body.
So what time should I receive UV rays? In the height of summer 11-17 hours should not receive sunlight, because this time infrared rays are too strong, generally can reach more than 1.5 calories per minute per cubic meter, the resulting temperature is 37 ℃ -45 ℃. Spring and fall season 7-10 o'clock, or 15-16 o'clock, this time, the sun's ultraviolet light is strong, infrared weak.
Ultraviolet damage to the human body
In the hot summer, the sun's ultraviolet light contained in the human body is difficult to avoid. Excessive exposure to UV rays from sunlight can cause damage to the human skin, eyes, and immune system. Ultraviolet rays can destroy human skin cells, resulting in wrinkles, pigmentation, making the skin age before it gets old, and in severe cases, producing solar dermatitis and sunburn, or solar keratosis of the skin and mucous membranes, 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, but also 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 company's website has been updated with the latest information about the company's products and services, and the company's website.
While excessive UV rays cause damage to the human body, the human body can not grow without UV rays. The 7-dehydrocholesterol in the skin is transformed into vitamin D3 by light irradiation, and vitamin D3 has an important physiological function in maintaining the concentration of calcium ions inside and outside human cells and regulating calcium and phosphorus metabolism. In countries with insufficient sunshine, rickets in infants and young children and adult osteomalacia and osteoporosis onset of more than one, the infant's thriving away from the right amount of sunbathing, the human body needs the right amount of ultraviolet rays, therefore, the right amount of light is still necessary.
Infrared rays (Infrared rays) are one of the many invisible rays of the sun's rays, which were discovered by the German scientist H?ssel in 1800 and are also known as infrared thermal radiation (Infrared radiation). The wavelength of infrared radiation on the solar spectrum is larger than that of visible light, with a wavelength of 0.75 to 1,000 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 l,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 many advances have been made. Infrared rays, especially far-infrared rays, have been widely used in the healthcare industry, and a large number of infrared products related to daily life have also appeared. In this paper, we mainly introduce the biological effect mechanism of infrared rays and the current status of its clinical application research.
I. The mechanism of infrared biological effect
Infrared ray is a kind of electromagnetic wave, when it radiates to the object through the radiation mode, the radiant energy absorbed by the object will be transferred to the atoms, molecules and other particles in the object, so that these particles will undergo irregular movement, causing the warming effect of the object, which is known as the far-infrared ray's primary effect, and is also known as the warming effect. Produce a primary effect at the same time, the object also occurs with other chemical, physical and other changes, which is called the object absorbs far infrared radiation after the secondary effect, also known as the secondary effect.
Infrared radiation has a strong penetrating power on human skin and subcutaneous tissue. The primary effect of external infrared radiation on the human body can increase the temperature of the skin and subcutaneous tissue accordingly, promote blood circulation and metabolism, and promote human health[1] . Infrared physiotherapy on the tissue thermal effect, anti-inflammatory effect and promote regenerative effect has been clinically recognized, usually the treatment are used on the lesion site direct irradiation. Near-infrared micro-irradiation therapy has a significant effect on the improvement of microcirculation, especially on the improvement of micro-blood flow. After irradiation, capillary blood flow is accelerated, erythrocyte aggregation is reduced, and subpapillary venous plexus stasis is reduced or disappeared, thus improving the nutrition, metabolism, repair, and function of the tissues and vital organs of the body [2].
The mechanism of the secondary effect of infrared radiation on the human body is not yet fully understood.
Some scholars believe that far infrared rays can produce *** vibration effect on cells, mainly caused by the vibration of water molecules inside and outside the cell, so that the cell activation, the occurrence of a series of beneficial to the health of the cellular 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 microcirculation of the human body. It acts on the human body water molecules can be aged in the body of large molecules to produce *** vibration cracking, reassembled into smaller water molecules, in the process, adsorbed on the surface of the aged molecules of pollutants can be removed, the specific gravity of the 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, thus enhancing the normal function of human cells, resulting in an increase in bactericidal ability, immunity, and so on. 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 blood lipid [lipid peroxide], reducing the deposition of intravascular lipids, so that the blood vessel wall smooth, thus reducing atherosclerosis, cataracts and other cardiovascular diseases or ophthalmic diseases, the human body's health play a good role in the promotion of the efficacy of [3].
Pang Xiaofeng studied the mechanism and characteristics of biological energy transfer released by hydrolysis of ATP molecules, and concluded that infrared light has biological effects on living things (including human beings) and medical functions mainly come from the non-thermal biological effects of infrared light. 1-7μm infrared light waves can be transmitted through the skin to the cells, and are absorbed by protein molecules. Protein molecules can and can only absorb or emit infrared rays with wavelengths of 1-3.5μm and 5-7μm, and the absorption of infrared rays with this range of wavelengths can lead to the quantum vibration of amide bonds in protein molecules, which can make the bioenergy transfer smoothly from one place to another, and keep the living organisms in a normal state to maintain the growth, development and health of the living organisms. The bioenergy to maintain the normal operation of the life system is provided by the hydrolysis of ATP, but once the ATP molecule or ATP enzyme (the hydrolysis of ATP requires the participation of enzymes) or water is insufficient, or the structure and conformation of proteins are altered or aberrated, etc., the bioenergy provided is insufficient to cause the normal vibration of the amide bond or the bioenergy cannot be transferred 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].
Research on the effect of infrared radiation on the immune function of the body is still in its infancy, and it is easier for mid-wave infrared rays to act on immune cells and promote their biological functions in various wavelengths of infrared rays. The role of infrared radiation in addition to its wavelength, but also the number of photons emitted, that is, with the intensity of radiation and radiation time, excessive infrared radiation may also cause adverse effects on the body, the detailed mechanism needs to be further elucidated. Cao Zhiran et al. believe that infrared radiation on the body's immune system has an indirect effect and direct effect. 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. Direct effect means that infrared radiation absorbed by the body can enhance the biological field around the immune cells and immune organs, so that their activity and mutual regulation is enhanced, infrared photons can be directly affected by the immune cells, including immune cell surface receptors (such as PHA-R, TCR, L-2R, etc. on the surface of the T-cells) and some enzymes, thus activating the cells, and making the cells proliferate and differentiate [5]. The mechanism of its action is hypothesized by Mao et al.] 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 through the neurohumoral reflex pathway on the one hand, and through the meridian conduction pathway on the other hand, which is not yet well understood, positively affecting the activities of biological macromolecules, cells, and organs, and thus having an overall benign effect [2].
Two, 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 a 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 through the cornea into the eye, the aqueous humor, iris, lens and vitreous fluid absorption of part of the infrared light and lead to cataract, called "infrared cataract", both 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 operating age of eyesight has a significant trend of decline, crystal clouding detection rate of 9.46%, and found that the distance from the heat source and the age of the post related to [6]. Some studies have also pointed out that ultraviolet (UVR) and infrared (IFR) damage to the eye and skin is an important aspect of occupational damage in welding operations, and UVR and infrared light during welding operations can cause corneal and crystal damage [7].
Infrared light from sunlight has a different effect on skin damage than ultraviolet light. Ultraviolet light mainly causes photochemical and photoimmunological reactions, whereas infrared radiation produces reactions due to molecular vibration and temperature increase. The thermal radiation caused by infrared rays penetrates the skin more than UV rays. 25% to 65% of its radiation reaches the epidermis and dermis, and 8% to 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 manifestations are red papules, premature aging of the skin and pigmentation disorders. Elevated skin temperature, capillary expansion, congestion, increased epidermal water evaporation and other direct adverse effects on the skin.
Infrared rays also enhance the damaging effects of ultraviolet rays on the skin, accelerating the skin's aging process. Using the same sunscreen products and the same energy intensity of ultraviolet rays, the SPF value measured in the natural outdoor sunlight (sun protection factor) is significantly lower than that measured in the laboratory under artificial light sources of sunscreen effectiveness, which is due to the natural sunlight, the skin by ultraviolet and infrared rays caused by the dual role of the cause. Infrared and UV play the same role in accelerating tissue degeneration. Infrared light also promotes the development of UV-induced skin cancer [8].
Three, infrared biological effects of clinical applications
Infrared rays can be absorbed by the superficial tissues of the body, there is a significant drying and dehydration effect, so that the local tissue blood circulation 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]. Some experiments have shown that bioceramic far infrared rays have significant efficacy in the treatment of burns. For the treatment of injury pain, the efficacy of chronic soft tissue injury is the best [11]. Clinical care observations have found that far infrared protective gears made of ultrafine ceramic particles added to traditional textile materials such as waist protectors, knee protectors, elbow protectors, wrist protectors, and neck collars have significant effects in anti-inflammation, swelling, blood circulation, pain relief, energizing the meridians, and improving microcirculation. It is more effective than magnesium sulfate wet heat compress, hot water bag heat 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 controlled by washing with external disinfectant drugs and keeping dry, which had poor therapeutic effect and was easy to recur. Using far-infrared radiation heating bed for the treatment of children with red buttocks and buttock ulcers, the average healing time of the treatment group was shortened and the effective rate was higher compared with the control group [13]. The rewarming problem in the treatment of neonatal scleroderma is an important part of whether the treatment can be successful, in the past, the gradual rewarming effect of the ordinary warming box is poor, and now the far-infrared rays are used to quickly rewarm the child's morbidity and mortality rate decreased significantly, and the success rate of resuscitation was significantly improved [14].
Flap necrosis is a common postoperative complication in plastic surgery, mainly due to microcirculatory disorders, and there is no ideal way to prevent and treat it. Jiang et al. investigated the effects of far-infrared rays in the 2.5-15 μm wavelength band 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 to increase the survival rate of skin flaps without obvious side effects within the range of therapeutic doses [15].
Japanese scholars have reported that the use of linear polarized infrared light in the treatment of various types of pemphigus vulgaris has significant efficacy [16].
Linear polarized light near infrared light is used for the treatment of temporomandibular joint pain caused by rheumatoid arthritis with short course and good efficacy [17]. Deformational arthritis using point linear polarized light near-infrared therapy device irradiation treatment and traditional local nerve block treatment, although the number of treatments in the near-infrared group is more than the traditional nerve block group, but the therapeutic range is wide, to avoid the pain of the local nerve block treatment to the patient, the apparent efficiency is higher, and the effect of long-lasting is not easy to recur. The mechanism may be that the light plays the role of photoelectric energy stimulation, electromagnetic wave effect and photochemical effect, which can inhibit the excitation of the nerve, relax the muscle, diastolic 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 treatment with low-temperature stimulated far-infrared rays, and found that low-temperature stimulated far-infrared rays have a wide range of biological effects based on the low-temperature thermal power effect, which can reduce blood viscosity of cardiovascular and cerebrovascular patients, prevent thrombosis, improve microcirculation, and alleviate the symptoms of chest tightness, palpitations, dizziness, numbness, etc. [19].
Near-infrared radiation therapy has a certain regulating effect on the immune function of CAH patients, patients with SG, IgG, γ-globulin decreased, ANA, RF turned negative, SA, CH50, C3 increased, and 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 of mice and the number of macrophages in the spleen [5], and also have a good effect on the body's free radical metabolism and the activity of N K cells [2].
Infrared irradiation of the bladder area for the treatment of urinary retention is painless for the mother, does not increase the amount of postpartum hemorrhage, and is easy to be accepted by the mother compared with other drug therapies. After infrared light 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, through the thalamus reflex to make the vascular smooth muscle relaxation, vasodilatation, blood circulation to strengthen, promote the absorption of exudate, facilitate the inflammation and swelling subside, and reduce the tension and spasm of the muscle, so that the treatment of urinary retention effect is obvious [21].
Gai Qifeng et al. used far-infrared irradiation with a wavelength of 2-25 μm to irradiate the lower abdominal pressure and pain area (including Qihai, Guanyuan, and Dangwei points) to treat pelvic inflammatory masses. 62 patients were diagnosed by obstetrics and gynecology clinic examination and ultrasound, and all of them had lower abdominal pain and pressure, and all of them were palpated with cystic masses on gynecological examination, and the apparent efficiency of healing was 88.6%, and the total effective rate was 96.6%. Far infrared irradiation can increase the local microcirculation function, enhance the ability of leukocytes to travel and phagocytosis, and promote the absorption of inflammation[22].
Some people have used 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 has an obvious alleviating effect on hyperglycemia in diabetic rabbits, and its metabolic regulation mechanism is to inhibit the activity of cyclic nucleotide cyclase (AC) while activating the activity of phosphodiesterase (PDE), so that cyclic adenosine monophosphate (cAMP) synthesis is blocked and hydrolysis is accelerated, and the level of cAMP decreases, and then the blood glucose decreases [24].
Some people have explored the effect of far infrared light on endogenous opiates in the brain of S180 rats by in vivo experiments, and found that the content of β-endorphin and leucine enkephalin in the brain of all groups treated with middle infrared light increased significantly. Enkephalinergic interneurons are thought to form axial-axial synapses with nociceptive afferent axons, which can produce potent pain-suppressing effects. This provides a theoretical basis for the clinical application of middle 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 or reduced activity of antioxidant enzymes can cause lipid peroxidation damage to cell membranes and consequently lead to cell death. It has been documented that tumor hosts have a reduced ability to scavenge free radicals, suggesting that natural antioxidants are deficient in antioxidant enzymes. Teng Yanjie et al. explored the changes in free radical metabolism in the liver of tumor-bearing rats through in vivo experiments, and found that the application of mid- and far-infrared light therapy resulted in a significant increase in the activities of hepatic SOD and GSH-Px, as well as a significant decrease in the content of MDA, which is a peroxidation product of double-bonded fatty acids, and whose content responds to the concentration of lipid peroxides. Middle and far infrared rays significantly reduce the MDA content in liver tissue of hormonal rats due to activation of cells, and liver SOD and GSH-Px activities are significantly elevated, which leads to the enhancement of free radical scavenging ability of the tumor host, and inhibits 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 component of many substances in the body, they have a very close relationship with growth and development, cardiovascular and cerebrovascular diseases, immune function, and aging of the body, etc. However, there is no sure treatment for the excess or decrease of trace elements caused by various diseases. Wang Jianjie et al. studied the effect of general-purpose broad-spectrum therapeutic instrument irradiation on trace elements in the liver of mice, and found that the peak wavelength of 7-10 μm in the far-infrared irradiation on the imbalance of trace elements can be adjusted in a bidirectional manner, and for the normal content can also promote its absorption, and play a very good role in preventing, treating, and health care [27].