Excessive exposure to ultraviolet rays can burn the skin, or cause senile cataracts and even skin cancer. However, moderate ultraviolet rays have many benefits to the human body:
There is a basal cell in the human epidermis, which contains "melanogen", which is a tyrosine substance. Under the action of ultraviolet rays, "melanogen" turns black and deposits on the surface of tanned skin, making the skin evenly dark brown. This is an important reason for skin tanning. This deposited pigment can absorb more light energy, quickly convert it into heat energy, and stimulate sweat glands to secrete heat. Sunbathing can kill bacteria on the skin.
Promote calcium and phosphorus metabolism There are sterols in human skin, which can be converted into vitamin D after being irradiated by ultraviolet rays in the sun. Vitamin D can improve the metabolism of calcium and phosphorus after entering the blood, and has anti-rickets, osteomalacia and osteoporosis effects on the elderly.
Enhance the body's immunity. Ultraviolet irradiation in sunlight can stimulate the hematopoietic function of human body, increase the number of red blood cells and hemoglobin, improve the quality of red blood cells, improve muscle activity, reduce blood pressure, blood sugar and cholesterol, increase human immunity, promote the oxygen absorption capacity and metabolism of human cells, relieve asthma and joint pain, relax muscles and promote blood circulation, and enhance physical fitness.
So, when should I receive ultraviolet radiation? In midsummer, 1 1- 17 is not suitable for exposure in the sun, because the infrared ray is too strong during this period, which can generally reach more than 1.5 calories per cubic meter per minute, resulting in temperatures of 37℃-45℃ and 7- 10 in spring and autumn.
Harm of ultraviolet rays to human body
In hot summer, it is inevitable that ultraviolet rays contained in the sun will irradiate the human body. Excessive ultraviolet rays can cause harm to human skin, eyes and immune system. Ultraviolet rays can destroy human skin cells, lead to wrinkles and spots, make the skin aging before it is old, and in severe cases, produce solar dermatitis and sunburn, or solar keratinization of skin and mucosa, which may lead to cancer. The eye is a sensitive organ of ultraviolet rays, which can damage the lens and is the cause of senile cataract.
In hot summer, the sun's ultraviolet intensity is the strongest from 10 to 3 pm, so outdoor activities should be avoided to avoid the harm of ultraviolet rays to human body. Even if you need outdoor activities during this time, don't forget to hold an umbrella, wear a sun hat or sunglasses, use skin care agents and sunscreen produced by regular manufacturers, and try to wear white or light-colored clothes to reduce unnecessary damage caused by ultraviolet rays.
Although excessive ultraviolet rays are harmful to human body, the healthy growth of human body is inseparable from ultraviolet rays. 7- dehydrocholesterol in skin is converted into vitamin D3 by light. Vitamin D3 has important physiological functions in maintaining calcium ion concentration inside and outside human cells and regulating calcium and phosphorus metabolism. In countries with insufficient sunshine, rickets in infants and osteomalacia and osteoporosis in adults often occur. Without proper sunbathing, infants cannot thrive. Therefore, the human body needs proper ultraviolet rays.
Infrared ray is one of the many invisible rays of the sun, which was discovered by German scientist Huxley in 1800. Also called infrared radiation. In the solar spectrum, the wavelength of infrared ray is greater than that of visible light, with a wavelength of 0.75 ~1000μ m. Infrared ray can be divided into three parts, namely near infrared ray with a wavelength of 0.75. Mid-infrared, the wavelength is between 1.50 ~ 6.0μ m; Far-infrared ray has a wavelength of 6.0 ~1000μ m. In recent years, due to the improvement of detection equipment and the in-depth research, people have a more comprehensive understanding of the physical properties and biological effects of infrared ray, and have made a lot of progress. Infrared rays, especially far infrared rays, have been widely used in the medical and health care industry, and various infrared products related to daily life have also appeared in large numbers. This paper mainly introduces the biological effect mechanism of infrared ray and its clinical application research status.
First, the mechanism of infrared biological effect
Infrared ray is an electromagnetic wave. When it radiates to an object in the form of radiation, the radiant energy absorbed by the object is transferred to atoms, molecules and other particles in the object, which makes these particles move irregularly and causes the temperature of the object to rise. This is the so-called primary effect of far infrared rays, also known as warming effect. When the primary effect occurs, other chemical and physical changes will also occur in the object, which is called the secondary effect after the object absorbs far infrared radiation, also known as the secondary effect.
Infrared rays have strong penetrating power to human skin and subcutaneous tissue. The primary effect of external infrared radiation on human body is to raise the temperature of skin and subcutaneous tissue, promote blood circulation and metabolism, and promote human health [1]. The thermal effect, anti-inflammatory effect and regenerative effect of infrared physiotherapy on tissues have been clinically confirmed. Usually, direct irradiation is used to treat lesions. Near-infrared micro-irradiation therapy has a significant effect on improving microcirculation, especially micro-blood flow. After irradiation, the blood flow velocity of capillaries is accelerated, the phenomenon of red blood cell aggregation is reduced, and the phenomenon of blood stasis in inferior papillary vein plexus is alleviated or disappeared, which has a positive effect on improving the nutrition, metabolism, repair and function of body tissues and important organs [2].
At present, the mechanism of the secondary effect of infrared rays on human body is not completely clear.
Some scholars believe that far infrared rays can vibrate cells, mainly causing the vibration of water molecules inside and outside cells, activating cells and causing a series of biochemical and histochemical changes beneficial to health [1]. Others think that the far infrared ray with the wavelength of 8 ~ 14 micron can be called "the light of life". Can significantly improve human microcirculation. When it acts on water molecules in human body, it can produce * * * vibration, which causes the aging macromolecular groups in human body to crack and recombine into smaller water cluster. In this process, the pollutants adsorbed on the surface of aging molecular groups are removed, the specific gravity of water increases, the water molecules attached to the surface of cell membrane increase, and the activity and surface tension of cells increase. Due to the increase of water molecules penetrating into the cell membrane, the activity of intracellular calcium ions is enhanced. So as to enhance the normal function of human cells and improve the sterilization ability and immunity. In addition, it can cut off the double bond or triple bond of unsaturated fatty acids in blood, and saturated fatty acids are not easy to be oxidized into blood lipids [lipid peroxide], which reduces the deposition of lipids in blood vessels and makes the blood vessel wall smooth, thus reducing the occurrence of cardiovascular diseases or ophthalmic diseases such as arteriosclerosis and cataract, and playing a good role in promoting human health [3].
Pang Xiaofeng studied the mechanism and characteristics of biological energy transfer released by ATP molecule hydrolysis, and thought that the biological effect and medical effect of infrared rays on organisms (including people) mainly came from the non-thermal biological effect of infrared rays. 1 ~ 7 micron infrared wave can be transmitted to cells through skin. Protein molecules are absorbed by protein molecules, and can and can only absorb or emit infrared rays with wavelengths of 1 ~ 3.5 microns and 5 ~ 7 microns, which can lead to the quantum vibration of amide bonds in protein molecules, so that biological energy can be smoothly transferred from one place to another, and life is in a normal state. Maintain the growth, development and health of life. The biological energy to maintain the normal operation of life system is provided by the hydrolysis of ATP. However, once ATP molecules or ATPase (ATP hydrolysis requires the participation of enzymes) or water is insufficient, or the structure and conformation of protein are changed or distorted, the provided biological energy is not enough to cause the normal vibration of amide bonds or the normal transfer of biological energy. When biological tissues can't get enough energy, they can't grow normally, which will induce various diseases. In this case, if infrared rays with the above wavelength can be irradiated and absorbed by protein, protein molecules can be restored to normal, and biological energy can be transmitted normally, so that biological tissues can be restored from pathological state to normal state. This disease can be cured. In the clinical trials of infrared medical instruments, it has also been proved that infrared rays with certain medical effects on organisms or people are just within this wavelength range, that is, 0.8 ~ 1.6 microns and 4.8 ~ 7 microns [4].
The research on the effect of infrared ray on immune function is still in its infancy. Among all infrared rays, medium-wave infrared rays are more likely to act on immune cells and promote their biological functions. The function of infrared ray is not only related to its wavelength, but also related to the number of photons it emits, that is, to the radiation intensity and radiation time. Excessive infrared radiation may also have adverse effects on the body. The detailed mechanism needs to be further clarified. Cao Zhiran and others believe that infrared radiation has indirect and direct effects on human immune system. Indirect effect means that infrared radiation can regulate the state of other systems of the body, such as nervous system and endocrine system, so as to achieve the purpose of regulating the immune system. Direct action means that infrared radiation can enhance the biological field around immune cells and immune organs after being absorbed by human body, thus enhancing their activity and mutual regulation. Infrared photons can directly act on the stimulated points of immune cells, including receptors on the surface of immune cells (such as PHA-R, TCR, L-2R, etc.). T cell surface) and some enzymes, thus activating cells and making them proliferate and differentiate [5]. Mao Wen and others speculate that the mechanism of action is that infrared rays may activate deep tissue receptors, and its physiological and biochemical effects may have a positive effect on the activities of biological macromolecules, cells and organs through the neurohumoral reflex pathway on the one hand, and the meridian conduction pathway that has not been fully understood at present, thus producing overall benign effects [2].
Second, the possible adverse effects of infrared rays on the human body
Thermal radiation is also called infrared radiation. The main characteristics of high temperature working environment in iron and steel metallurgical enterprises are strong thermal radiation and high temperature. Especially in hot rolling and medium sintering machines in iron and steel smelting and Honggang, it is a typical infrared thermal radiation contact operation. Short-wave infrared rays with a wavelength of 0.8 ~ 1.2 micron can enter the eyeball, aqueous humor, iris, lens and vitreous humor through the cornea to absorb some infrared rays and cause cataracts, which are called "infrared cataracts". It was first seen by glass workers at home and abroad and workers in iron and steel smelting. Cao Duozhi and others found that the thermal radiation hazard of iron smelting in front of the furnace was still very serious, and with the increase of working years, the vision decreased obviously, and the detection rate of crystal turbidity reached 9.46%, which was related to the distance of heat source and the working years of this post [6]. Some studies have also pointed out that the harm of ultraviolet rays (UVR) and infrared rays (IFR) to eyes and skin is an important aspect of occupational injuries in welding operations.
Infrared rays in sunlight do different harm to the skin than ultraviolet rays. Ultraviolet rays mainly cause photochemical reactions and photoimmune reactions, while infrared rays cause reactions caused by molecular vibration and temperature rise. The thermal radiation caused by infrared rays penetrates the skin more than ultraviolet rays. 25% ~ 65% of its radiation can reach epidermis and dermis. 8% ~ 17% can reach subcutaneous tissue. Infrared rays have direct adverse effects on the skin through its thermal radiation effect, such as skin temperature rise, capillary dilation, congestion, and increased evaporation of epidermal water. The main manifestations are red papules, premature aging of skin and pigment disorder. The skin temperature rises, the capillaries dilate and congest, and the epidermis water evaporates, which has a direct adverse effect on the skin.
Infrared rays can also enhance the damage of ultraviolet rays to the skin and accelerate the process of skin aging. Under the same sunscreen products and the same intensity of ultraviolet rays, the SPF value (sun protection coefficient) measured in outdoor natural sunlight is obviously lower than that measured in laboratory artificial light source, which is caused by the dual effects of ultraviolet rays and infrared rays on the skin under natural sunlight. Infrared and ultraviolet rays have the same effect in accelerating tissue degradation. Infrared rays can also promote the development of skin cancer caused by ultraviolet rays [8].
Third, the clinical application of infrared biological effects.
Infrared rays can be absorbed by superficial tissues on the body surface, which has obvious drying and dehydration effects, accelerates the blood circulation of local tissues, and plays an anti-inflammatory and analgesic role. Clinical use of safflower oil plus far infrared radiation to treat bedsores has found good curative effect and quick effect [9]. The far infrared ray was used to treat herpes zoster, and the results showed that the time to stop pain, blister and dementia was shorter than that of the control group [10]. Bioceramic far infrared ray has obvious curative effect on burn. Chronic soft tissue injury has the best effect on injury pain [1 1]. Clinical nursing observation shows that far-infrared protective devices made of ultrafine ceramic particles are added to traditional textile materials, such as waist protection, knee protection, elbow protection, wrist protection and neck circumference. It has obvious functions of diminishing inflammation, reducing swelling, promoting blood circulation, relieving pain, dredging meridians and improving microcirculation. It is superior to magnesium sulfate wet hot compress, hot water bottle hot compress and drug sealing, and can avoid the pain caused by sealing [12]. Neonatal red buttocks and ulcers are usually prevented and treated by external disinfectant cleaning and keeping dry. Poor curative effect, easy to relapse. Far-infrared radiation and hotbeds are used to treat children's red buttocks and hip ulcers. Compared with the control group, the average cure time in the treatment group is shorter and the effective rate is higher [13]. The problem of rewarming in the treatment of neonatal scleredema is an important link in the success of treatment. In the past, the effect of gradual rewarming with ordinary incubators was poor. Now, after rapid rewarming with far-infrared radiation, the mortality rate of children is obviously reduced, and the success rate of rescue is obviously improved [65438+]
Skin flap necrosis is a common postoperative complication in plastic surgery, and the main reason is microcirculation disturbance. At present, there is no ideal control method. Ping Jiang directly observed the microcirculation changes of random skin flap on the back of rats in vivo, and discussed the influence of 2.5 ~ 15μ m band far infrared ray on the survival of skin flap. It is found that far infrared local irradiation has biological effects similar to vasodilators, which can improve microcirculation and improve the survival rate of skin flap, and has no obvious side effects within the therapeutic dose range [15].
Japanese scholars have reported that linearly polarized infrared rays have obvious curative effects on various types of alopecia areata [16].
Linear polarized near infrared ray is effective in treating temporomandibular joint pain caused by rheumatoid arthritis [17]. Compared with the traditional local nerve blocking therapy, point-line polarized near infrared ray has a wide range of treatment for deformed arthritis, which can avoid the pain caused by local nerve blocking therapy and has a high effective rate. The mechanism may be that light can stimulate photoelectric energy, electromagnetic wave and photochemical action, so it can inhibit nerve excitement, relax muscles, relax blood vessels, increase blood flow, promote lymphatic circulation and promote the production of active factors, thus playing a therapeutic role [18].
Some people observed the blood viscosity of 66 patients with cardiovascular and cerebrovascular diseases before and after the treatment of low-temperature excitation of far infrared rays, and found that low-temperature excitation of far infrared rays has a wide range of biological effects, which can reduce the blood viscosity of patients with cardiovascular and cerebrovascular diseases, prevent thrombosis, improve microcirculation, and relieve chest tightness, palpitation, dizziness, numbness and other symptoms [19].
Near infrared therapy can regulate the immune function of CAH patients, such as the decrease of SG, IgG and γ-globulin, the negative of ANA and RF, the increase of SA, CH50 and C3, and the normalization of humoral immunity [20]. Infrared radiation can also promote the induction of L-2 by Con-A, significantly improve the ADCC effect of rat spleen cells and improve the transformation rate of PHA-stimulated T lymphocytes in mice. The increase of spleen index increases the number of peripheral blood lymphocytes and spleen macrophages in mice [5], and also has a good effect on free radical metabolism and N K cell activity [2].
Compared with other drug therapies, infrared radiation to the bladder area for the treatment of urinary retention has no pain to the parturient, does not increase postpartum hemorrhage, and is easily accepted by the parturient. After infrared rays irradiate the skin, the absorbed energy is converted into heat energy, which raises the skin temperature, stimulates the heat receptors in the skin, relaxes the smooth muscle of blood vessels, dilates blood vessels, strengthens blood circulation through thalamus reflex, promotes the absorption of exudates, helps the inflammation to subside, and reduces muscle tension and spasm, so the therapeutic effect on urinary retention is obvious. 49860.6886868666 1
Gai Qifeng et al. used far infrared ray with wavelength of 2 ~ 25μ m to irradiate the tenderness area of abdomen (including points of Qihai, Guanyuan and pulse) to treat pelvic inflammatory mass. 62 patients were diagnosed by clinical examination of obstetrics and gynecology and B-ultrasound, and all of them had lower abdominal pain and tenderness. Gynecological examination touched cystic mass, the effective rate was 88.6%, and the total effective rate was 96.6%.
208 cases of infantile enterospasm were treated by far infrared radiation, and it was found that the curative effect was obviously better than that of drug treatment, and it was simple and easy, with no side effects, and the children were happy to accept it [23].
Infrared radiation can obviously alleviate hyperglycemia in diabetic rabbits, and its metabolic regulation mechanism is to inhibit the activity of cyclic nucleotide cyclase (AC), activate the activity of phosphodiesterase (PDE), hinder the synthesis of cyclic adenosine monophosphate (cAMP), accelerate hydrolysis, and reduce the level of cAMP and blood sugar [24].
The effect of far infrared rays on endogenous opioids in the brain of S 180 tumor-bearing mice was studied by in vivo experiments. The results showed that the contents of β -endorphin and leucine-enkephalin in the brain of rats in each group increased significantly after far infrared radiation. Enenkephalin intermediate neurons are thought to form axonal synapses with pain afferent axons, which have powerful analgesic effects. This provides a theoretical basis for the clinical application of far infrared rays to treat and relieve the pain of tumor patients and relieve herpes zoster and limb pain.
In many diseases, the excessive production of reactive oxygen species or the decrease of antioxidant enzyme activity will lead to lipid peroxidation damage to cell membrane and then lead to cell death. Some data show that the ability of tumor host to scavenge free radicals is reduced, which indicates that the antioxidant enzymes of natural antioxidants are insufficient. Teng et al. discussed the changes of free radical metabolism in the liver of tumor-bearing mice through in vivo experiments. It was found that the activities of SOD and GSH-Px in the liver were significantly increased while the content of MDA was significantly decreased by using mid-infrared therapy. MDA is the product of double bond fatty acid peroxide, and its content reflects the concentration of lipid peroxide. The activities of SOD and GSH-PX in the liver of tumor-bearing mice decreased obviously, because the middle and far infrared rays activated the cells, enhanced the ability of tumor host to scavenge free radicals, and inhibited the growth and proliferation of tumor cells [26].
Trace elements play a very important role in the biochemical process in the body. As an important part of various substances in the body, they are closely related to the growth and development of the body, cardiovascular and cerebrovascular diseases, immune function, and aging of the body. 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 with broad-spectrum therapeutic instrument on trace elements in the liver of mice. It is found that far-infrared radiation with the peak wavelength of 7 ~ 10μ m can adjust the imbalance of trace elements in two directions, promote the absorption of normal contents, and play a good role in disease prevention, treatment and health care [27].