Beijing has started the high-temperature roasting mode, followed by a series of rumors about "heat" — — Sunscreen clothes are not sunscreen after washing, heat stroke is a large heatstroke, and drinking mineral water that has been exposed to the sun in the car will cause cancer, etc., which are concentrated in the latest scientific rumor list.
The monthly "scientific" gossip list is guided by Beijing Science and Technology Association, Beijing Municipal Committee Network Information Office, Capital Internet Association, and jointly released by Beijing Science and Technology Journalists Editors Association and Beijing regional website joint rumor platform.
Rumor has it that heatstroke is heatstroke
truth Some people think that heatstroke is heatstroke, not serious. In fact, it is not exactly the same as heatstroke, and it should not be taken lightly. Generally, the body temperature of heatstroke patients often exceeds 38℃, accompanied by facial flushing, profuse sweating, burning skin, nausea and vomiting, or cold limbs, pale face, decreased blood pressure, rapid pulse and other symptoms.
Heat stroke is the most serious emergency related to high temperature, that is, "severe heatstroke", which is a serious and fatal disease with skin burning, consciousness disorder (such as delirium, convulsion, coma) and multiple organ dysfunction. Once it happens, the death rate will be high.
Heat stroke does not happen suddenly. Before heatstroke develops into heat stroke, it will first experience "threatened heat stroke" and "mild heat stroke". To prevent heat stroke, we must first avoid heat stroke. Try to avoid staying in high temperature (high humidity) and unventilated environment, and avoid high temperature when traveling and do a good job of sun protection. In addition, some heatstroke prevention drugs can be prepared appropriately. When you have to do homework or activities outdoors, you should pay attention to your physical condition, drink plenty of water and rest in time. If you travel by car, don’t leave children and pets in the car. Pay attention to avoid dehydration and ensure adequate sleep.
Rumor has it that the sunscreen will be invalid once it is cleaned.
truth Is it true that sunscreen clothes can’t be washed with water? Excessive cleaning of sunscreen clothing will indeed lead to a decline in the anti-ultraviolet performance of clothing, but normal cleaning is no problem. Sunscreen clothing can enhance the anti-ultraviolet effect of clothes by adding ultraviolet absorbent and anti-ultraviolet agent to the cloth or adding sunscreen coating on the surface of the fabric, just like coating a lot of sunscreen on the surface of clothes.
Professional sun protection clothes usually indicate the sun protection index on the tag, which is the result of the standard inspection of national professional institutions. Only when UPF is greater than 40 and T (UVA) is less than 5%, can they be qualified as "anti-UV products" and can they be called "sun protection clothes".
Under normal circumstances, the sunscreen effect will not be significantly reduced when the cleaning times of sunscreen clothing are less than 30 times. After more than 30 times, it depends on the water resistance of anti-ultraviolet agents and the processing level of sunscreen clothing. There are two main processes for adding ultraviolet shielding agent to clothes: one is to add it to spinning raw materials, and the other is to soak or coat the fabric. Generally speaking, the ultraviolet shielding agent added during spinning can be better combined with raw materials, and the ultraviolet resistance is still considerable after repeated washing; However, the ultraviolet shielding agent attached to the fabric after weaving is easier to be peeled off when washing.
The service life of sun protection clothing is usually several months to one year, and the sun protection ingredients may be damaged to varying degrees, and the sun protection effect is definitely worse than when it was just bought. Replacing a new sunscreen suit every year can ensure a good sunscreen effect.
Gossip exposed mineral water can cause cancer.
truth Qualified mineral water bottles in the market are usually made of food-grade plastics, namely polyethylene terephthalate (PET). PET is not only acid-resistant, alkali-resistant and grease-resistant, but also can withstand the corrosion of most solvents. At the temperature below 120℃, PET is non-toxic and tasteless, and it is safe to pack drinks. However, at high temperature, it will slowly dissolve and release some organic solvents harmful to human health.
The temperature in the car, even in summer, is generally difficult to reach 120℃, so there is no scientific basis for the statement that "mineral water exposed in the car can cause cancer".
Gossip astronauts can’t be nearsighted
truth People have been circulating this statement — — Astronauts can’t be nearsighted, let alone wear glasses, because wearing glasses in space may bring accidental injuries. Indeed, the selection criteria for astronauts are indeed very high. However, at present, low myopia is also allowed to enter space.
In the ascending phase of the mission, there are complicated situations such as rocket vibration and overload. If astronauts wear frame glasses, it may lead to collision and other problems, so astronauts will not wear frame glasses (wearable contact lenses) at this stage. The environment of the space station is relatively stable, and you can wear frame glasses normally.
Over the years, aerospace engineering technology has made great progress, and the mission environment is no longer strict with astronauts’ physical fitness requirements; On the other hand, in the future, we need more front-line researchers to "go to heaven" for scientific research. Obviously, it is not appropriate to use myopia as a hard standard to select researchers, so low myopia is now allowed to enter space. It is worth mentioning that people with high myopia are still unable to travel in space. After all, people with high myopia may fall off their retinas when riding a roller coaster, and it is even more impossible to bear the huge acceleration when the rocket is launched.
Yang Liwei, deputy chief designer of China’s manned spaceflight project, once said that the selection criteria for astronauts are different with different tasks. "From the perspective of vision, high myopia is not good, and low myopia is ok. Several of our non-professional load expert astronauts wear glasses. "
Gossip moles should be removed or they will become cancerous.
truth Does the mole on our body really have a chance to develop into melanoma, a deadly malignant tumor, if it is not removed? In fact, nevus is a benign tumor of the skin. Most nevus are formed in response to sun exposure, and it is extremely unlikely that they will develop into melanoma.
It is also possible to remove these moles for aesthetic reasons, or to observe them regularly (monthly) for life, and pay attention to their color changes and texture changes (such as increased thickness). Some moles may develop into melanoma more easily and need to be paid attention to, including: congenital giant moles, dysplasia moles, multiple moles (more than 50), moles at the ends of limbs, moles or pigmentation in digestive tract and genitourinary tract, moles exposed to sunlight for a long time, etc. If the mole is suspected to be bad, it must be completely removed under the guidance of an experienced doctor and sent to biopsy for pathological diagnosis.
Myth "conjoined" cherries blame pesticides
truth In life, cherries we buy sometimes appear "twins" phenomenon, that is, there are two fruits on a fruit stalk. But this has nothing to do with medication. The incidence of abnormal fruit of cherries is closely related to the high temperature weather last year, not caused by pesticides.
From the botanical point of view, the abnormal fruit is caused by the appearance of multiple pistils during the flower bud differentiation of cherries. Studies have shown that if cherries encounter high temperature above 30℃ during flower bud differentiation (especially during sepals and petals differentiation), the incidence of deformed fruits will greatly increase in the second year without human intervention, and the proportion of conjoined double fruits will be higher with the increase of temperature. However, during this period (mid-July), the temperature in warm areas in China often exceeds 30℃, which easily leads to the formation of double pistils or even multiple pistils.
Gossip dry eye drops work
truth It is circulated on the Internet that "dry eye is ‘ Lack of water in eyes ’ As long as more drops of eye drops can be effectively relieved. This kind of practice is wrong, and it is likely to be counterproductive.
Dry eye, also known as dry eye, refers to a series of diseases caused by various factors, such as abnormal quality and quantity of tears or abnormal dynamics, which leads to the decline of tear film stability, accompanied by eye discomfort or ocular surface tissue lesions.
On the surface of our eyeball, there is a thin layer of liquid, that is, the "tear film". It consists of oil layer, tear layer and mucin layer. Although it is only a few microns thick, it is like the "lubricating oil" of eyes, which can keep the cornea and conjunctiva moist and improve the refractive performance of eyes.
When dry eye is not too serious, patients just need to take a rest and drop some artificial tears, and it seems that they can see things clearly again, so it is easy to take it lightly. In fact, dry eye is a manifestation of the disorder of tear film secretion, not just "water shortage". Although it sounds strange, a considerable number of patients are easy to stimulate the lacrimal gland and produce a lot of tears because the balance of the tear film is destroyed. However, the extra tears that flow out cannot effectively exist on the surface of the eye to moisten the cornea in the form of tear film.
External means can only help it gradually recover its physiological function, so we must pay attention to it at an early stage, get rid of bad habits in time, and don’t use eye drops indiscriminately to avoid getting worse. If there are symptoms of dry eyes, such as dry eyes, dry eyes and difficulty in opening eyes, please go to the ophthalmology department of a regular hospital immediately to determine the type of dry eyes and treat them symptomatically.
Rumor has it that the green peel is not ripe litchi.
truth This is a misunderstanding of fresh litchi. Litchi with green skin in the market is not picked before it is ripe. There are more than 300 kinds of lychees, many of which are not full of bright red. For example, the characteristic of "princess smile" is that the skin is green and red.
The characteristic of hanging green litchi is that the peel is red and purple, and there is a green line running straight through it, so it is named "hanging green". Good quality "Guanyin Green" litchi, even the peel is green when it is mature. It is best for consumers to determine whether the peel color is normal according to the variety of litchi. The fresh litchi peel is cracked, flat and regular, and feels tight and elastic; There are also some lychees with blue color, which may belong to insufficient light or undercooked, so it is best not to eat them.
Rumors are better absorbed by eating fruit before meals.
truth In fact, eating fruits before or after meals will not affect the digestion and absorption of both nutrients.
The main component of fruit is water, followed by a small amount of carbohydrates, protein, fat and a small amount of water-soluble vitamins and minerals. There is no direct correlation between the digestion and absorption of these nutrients and eating dinner. Therefore, you can choose the order of eating fruits according to your personal situation and habits. It should be noted that you should not be greedy or eat more than one kind of food in your diet, let alone overeat.
Text/reporter Li Jie
