June 2022 "Science" Rumors List: Only children get chickenpox? Will this summer be cold?

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Monthly "Science" Rumor List

The June 2022 "Science" Rumor List is Announced!

Let's look at the rumors and the truth

01Chickenpox is a disease that only children get

02The pungent smell you smell after opening the bag of Flammulina velutipes is formaldehyde

03Sudden body twitching during sleep is a sign of sudden death

04The bigger the mosquito bite, the more toxic it is

05The effectiveness of the new crown vaccine will become negative 4 months after injection

06Cold vortex only brings bad weather

07This summer will be cold due to the "aphelion phenomenon"

08The disposable gloves you wear when eating crayfish are useless

Chickenpox is a disease that only children get

gossip:

Chickenpox is highly contagious and is a childhood disease. As adults, people no longer get chickenpox.

the truth:

Although chickenpox is more common in children aged 2-10 years old, it is not exclusive to children. Adults can also get chickenpox. If it is not isolated and treated in time, other family members can easily suffer.

Chickenpox refers to an acute infectious disease caused by the initial infection of the varicella-zoster virus. Chickenpox can provide lifelong immunity, and the chance of reinfection is very small, which has led to the impression that "adults do not get chickenpox." In fact, people who have never had chickenpox or received the chickenpox vaccine are highly susceptible to chickenpox, and adults are no exception.

In addition, after chickenpox is cured, the virus does not disappear, but lurks in the dorsal root ganglia of the spinal cord. When the body's immune function weakens, it may induce the varicella-zoster virus to become active again, spreading along the peripheral nerves to the skin, causing shingles. The patient's rash contains a high concentration of varicella-zoster virus, and direct contact with the blister fluid can cause people who have never been infected with chickenpox to develop chickenpox.

The symptoms of chickenpox in adults are often more severe than those in children, and are often complicated by diffuse nodular pneumonia. The mortality rate is as high as 10% to 40%, so adults should also pay attention to preventing chickenpox.

The pungent smell you smell after opening the bag of Flammulina velutipes is formaldehyde

gossip:

The pungent odor that you smell after opening the bag of enoki mushrooms is because the merchant uses formaldehyde to "bleach" them. Eating them will not only damage your liver and kidneys, but can also cause cancer.

the truth:

When you open the packaging bag of Enoki mushrooms, you may smell a pungent odor. This is not because formaldehyde is added, but because the temperature changes during transportation, causing the Enoki mushrooms to switch from aerobic respiration to anaerobic respiration, thereby producing some volatile aldehyde gases.

Flammulina velutipes were originally yellow, and the reason they turned white was not because they were bleached with formaldehyde. Today, most of the Flammulina velutipes on the market are new varieties from Japan. Researchers found a genetically mutated white Flammulina velutipes among the yellow Flammulina velutipes, and then kept it for cultivation. This type of Flammulina velutipes not only has a good color, but also grows fast and has a high uniformity.

my country's Food Safety Law and Agricultural Product Quality Safety Law clearly stipulate that formaldehyde shall not be used as a food processing aid in production and operation.

Sudden body twitching during sleep is a sign of sudden death

gossip:

When you are about to fall asleep, your whole body suddenly shakes violently. This is a "strike" by the brain, causing the body to twitch out of control, which is a sign of sudden death.

the truth:

The phenomenon of the body shaking suddenly when falling asleep is called "sleep startle", also known as "hypnic twitch" or "hypnic myoclonus". This phenomenon is quite common and is not a sign of "sudden death".

When a person first falls asleep, part of the brain is already asleep, but another part is not completely asleep. As sleep deepens, the brain relaxes its control over the limbs. When the brain is stimulated by certain information inside and outside the body, a sudden twitch of the muscles in a part of the body may occur. This is sleep startle. It is reported that about 60%-70% of people have had this experience.

The bigger the mosquito bite, the more toxic it is.

gossip:

The size of the bump after being bitten by a mosquito can indicate the strength of the mosquito's toxicity. The larger the bump, the stronger the toxicity.

the truth:

After being bitten by a mosquito, the size of the mosquito bites on the body is closely related to the individual's immune system mechanism and has nothing to do with "mosquito toxicity."

The process of human reaction to mosquito bites is an allergic reaction process. There are four types of human allergic reactions: Type I allergic reaction is also called immediate allergic reaction, which occurs relatively quickly and the human body reacts violently. Common ones include penicillin allergic reaction, drug rash caused by drugs, allergic gastroenteritis caused by food, asthma attack, anaphylactic shock, etc. Type II allergic reaction is also called cytotoxic allergic reaction, such as blood transfusion reaction due to incompatible blood type. Type III allergic reaction is also called immune complex allergic reaction, such as partial glomerulonephritis after streptococcal infection, etc. Type IV allergic reaction is also called delayed allergic reaction. There will be no reaction after the first contact, but a reaction will be caused after the second contact with the antigen. For example, rejection reaction of organ transplantation and certain autoimmune diseases.

The reactions to mosquito bites are generally divided into local reactions and systemic reactions. The typical reaction is a local reaction: usually an immediate wheal rash accompanied by redness, swelling and itching, which is most obvious 20 minutes after the bite.

Local reactions generally have the following characteristics: people who have never been in contact with a certain type of mosquito will not react to the first bite of such mosquitoes, but subsequent bites will cause delayed local skin reactions and will immediately produce wheals.

Therefore, people who have never come into contact with a certain type of mosquito will not react to the first bite of such mosquitoes, but will immediately produce a wheal when bitten again. This type of local reaction belongs to type I hypersensitivity reaction (also known as rapid-type hypersensitivity reaction), which occurs relatively quickly and the human body's reaction is relatively violent. However, for people who are bitten repeatedly by the same type of mosquito, their immediate reaction will eventually disappear. Therefore, the local reaction of adults to mosquito bites is not as violent as that of children, because adults are "bitten" by mosquitoes.

The effectiveness of the new crown vaccine will become negative 4 months after injection

gossip:

Recently, some articles online claim that studies show that the effectiveness of the new crown vaccine has become negative in just a few months, which means that people who have been vaccinated are more likely to be infected.

the truth:

According to the original study, the effectiveness of the vaccine will decline over time, but the decline in effectiveness in the study is for mild cases. In addition to mild cases, the vaccine still has a good effect in preventing severe cases, reducing the risk of hospitalization, and reducing the risk of death. It is biased to say that the vaccine has failed because of the decline in effectiveness in protecting against mild cases.

A negative vaccine effectiveness number does not mean that the vaccine is having a counterproductive effect (increasing the risk of infection). The negative number is caused by potential bias factors in the data statistics process. The so-called "vaccine effectiveness becomes negative" means from a scientific point of view that there is no evidence that the vaccine can effectively reduce the risk of symptomatic infection, which is consistent with the meaning of zero effectiveness.

The effectiveness of the vaccine is multi-faceted. Even if the effectiveness in preventing infection decreases, the new crown vaccine still provides very critical effectiveness in preventing severe illness.

The cold vortex will only bring bad weather

gossip:

A cold vortex is synonymous with bad news. Its appearance means that severe convective weather such as hail, thunderstorms, strong winds, and short-term heavy rainfall are about to arrive.

the truth:

In meteorology, a cold vortex is also called a "cold vortex in the upper air". After the cold vortex system is formed, the upper air temperature becomes cold, which increases the instability of the atmospheric environment, making it easy for convection to develop, forming severe convective weather such as heavy rain, lightning, short-term strong winds, hail, short-term heavy precipitation, etc., accompanied by certain meteorological disasters. However, cold vortex weather does not necessarily bring rainfall, which also depends on the cooperation of the lower-level weather system.

For example, after the cold vortex from Inner Mongolia and Northeast China reaches the North China Plain, if there is a relatively strong vortex system in the lower atmosphere, the cooperation of high and low will meet the weather conditions for heavy rain. It is also related to the release of latent heat generated by precipitation.

If there is not enough precipitation, the cold vortex will bring people a refreshing cool breeze, dispel the stuffiness in summer, and create "high-value" weather with blue sky and white clouds in autumn. At the turn of summer and autumn in Beijing every year, the upper air is greatly affected by the northeastern cold vortex, and the transparency of the atmosphere is very high. At the same time, the ground is still mainly blown by southeast winds, which will bring sufficient water vapor from the ocean. Such favorable water vapor conditions, coupled with the radiation heating effect of the summer afternoon, are prone to convection, resulting in blue sky, white clouds, and good autumn weather.

This summer will be cold due to the "aphelion phenomenon"

gossip:

Starting from May 22 this year, the sun will move away from the earth and reach its "aphelion". The weather will become colder during this period and will last until August this year.

the truth:

The Earth's orbit does have a perihelion and aphelion, but the distance between the two is not much different, and the aphelion will not cause summer cold.

The closest point to the sun in the Earth's orbit is called the "perihelion". At this time, the Earth is about 147.1 million kilometers away from the sun. The farthest point from the sun in the orbit is called the "aphelion", and the distance is about 152.1 million kilometers. The Earth reaches perihelion in January every year and aphelion in July. Although the difference between the two points is 5 million kilometers, it is insignificant compared to the average distance from the Earth to the Sun. Through calculations, it was found that this difference only accounts for 3.3% of the average distance between the Earth and the Sun, which is like the difference between 100 meters and 103.3 meters, which is almost negligible. In fact, the solar radiation received by the Earth at perihelion is only less than 6% stronger than at aphelion.

Since the Earth is a "ball" with an inclination angle, the angle of sunlight received by a specific area is different in different months of each year, and therefore the energy is also different. Therefore, the periodic changes of the four seasons when the Earth revolves around the sun are more related to the angle of sunlight.

The disposable gloves I wear when eating crayfish are useless

gossip:

People wear disposable plastic gloves when eating crayfish and other foods. But after eating, their hands are still covered with red oil, which shows that these plastic gloves are completely useless.

the truth:

When touching food, the biggest role of wearing disposable gloves is not to prevent oil, but to block bacteria. Disposable gloves made of polyethylene material have the effect of blocking bacteria. Wearing them when eating crayfish can effectively prevent bacteria on the hands from entering the human body, thus achieving the purpose of healthy eating.

The raw materials of polyethylene used in the production of disposable gloves are mainly low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). According to the principle of "like dissolves like", when in contact with grease, low-density polyethylene and linear low-density polyethylene may swell to a certain extent, allowing grease molecules to pass through the disposable gloves through gaps that are invisible to our naked eyes. Therefore, it is difficult to completely block grease even if you wear disposable gloves.

It is worth noting that when using disposable gloves, try to buy products produced by regular manufacturers. Poor quality disposable gloves may have a greatly reduced performance and may also contain harmful substances.

The monthly "science" rumor list is guided by the Beijing Association for Science and Technology, the Beijing Municipal Cyberspace Administration, and the Capital Internet Association, and jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor-Refuting Platform, and is supported by the Science and Technology Journalists and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

Source: Beijing Science and Technology News Agency