Hearing Tang Ning's personal proposal, Eugenie was so confused that before she could agree or refuse, a girl's voice rang out: "Tang Ning! Where are you? ”

Tang Ning hurriedly let go of Eugenie in his arms and said, "It's Princess Victoria." ”

After informing Owenie of the information, he replied loudly: "Here I am! ”

Princess Victoria watched suspiciously, as Downing and the beautiful Earl came out of the bathroom.

Downing explained: "Introduction, this is the eldest princess Victoria, this is the Countess of Twa, Eugenie?" Miss Montiro. I was just presenting Mademoiselle Montijo to her latest invention – toothpaste. ”

It turned out to be the introduction of toothpaste, no wonder to stay in the bathroom, Princess Victoria, who was very confident in Tang's character, didn't think much about it, she was also curious about what toothpaste was, so Tang gave a brief introduction to the toothpaste and toothbrush, and also explained some science and technology that had not been talked about just now: "At present, the biggest enemy of human dental health is tooth decay, and my toothpaste not only tastes good, but also has a profound scientific truth, which can prevent tooth decay." I'll be publishing a paper on caries in the journal Nature in the near future, but I can now talk about how caries form. ”

Two female students sat honestly at the coffee table and listened to the teacher Windsor.

The mouth is a great incubator for bacteria. It is the main opening of the human body, where germs from the outside world come in through the air, dust, food, and survive there. Air can provide oxygen to aerobic bacteria, but some bacteria are anaerobic, and it doesn't matter, these bacteria can also find a place to hide and not be exposed to the air. Saliva constantly moistens the mouth, keeping its temperature at 35~36 degrees Celsius and the pH value at 6. 75～7。 25, which is the optimal growth temperature and pH for many species of bacteria. The amino acids and proteins in saliva can be used as nutrients for bacteria, and of course, food scraps are also their nutrients. The biggest impact on your teeth in food scraps is the sugars inside, which are broken down by bacteria and turned into acids such as lactic acid. Under acidic conditions (pH below 5. 5) The tooth will be "demineralized" – the calcium and phosphorus on the surface of the tooth enamel will be lost. However, the saliva neutralizes the acid, and the calcium and phosphorus in the saliva are deposited back on the tooth surface. Under normal circumstances, the demineralization and remineralization of the tooth are in equilibrium. Fluoride ions enhance tooth remineralization, and Downing's invention of fluoride in toothpaste is a major milestone in dental health.

In order for bacteria to multiply on the teeth, they must first be able to attach to the surface of the teeth, which also depends on the help of saliva. There are no bacteria on the surface of the newly grown or freshly cleaned teeth, when saliva flows through them, leaving a film of glycoproteins on the surface of the tooth so that the bacteria can adhere to it. Bacteria can stick to each other, even different species of bacteria can stick together. Layers of bacteria stick to the surface of the tooth, forming patches of pale yellow biofilm, also known as plaque. The first harm of plaque is that it disrupts the balance between demineralization and remineralization of the tooth, because saliva cannot penetrate and neutralize the acids underneath the plaque. Most bacteria are afraid of acids, but Streptococcus mutans and Lactobacillus are not, and they are at pH 4. At 5 o'clock, it can still grow and reproduce, so that the small environment of dental plaque becomes more and more acidic, and the demineralization of the tooth surface becomes more and more severe, and the caries appears, and it can no longer be recovered.

The second harm of dental plaque is that it can lead to periodontal disease. The plaque that grows between the gums irritates the gums, causing it to develop an inflammatory response and exacerbate the secretion of gingival sulcus fluid. The gingival crevicular fluid is mainly composed of serum and is rich in protein, which is an excellent nourishment for some bacteria, which can digest the protein. The result of protein degradation is the opposite of the result of sugar degradation, which makes the surrounding environment alkaline, and the acid-base balance maintained by saliva is broken in the other direction, and the pH value can exceed 7. 5。 Most bacteria in the oral cavity cannot survive in an alkaline environment, and basophilic bacteria such as Przewalskim intermediates and Porphyromonas gingivalis take the opportunity to multiply in large numbers and cause gingivitis.

Unlike the skin, mucous membranes, etc., the surface layer of the tooth does not fall off on its own, so the plaque on it does not fall off on its own, and external force is applied. The main purpose of brushing your teeth is to remove plaque. But there are some areas of the teeth that cannot be brushed with a toothbrush, that is, between the teeth, and those places have to be flossed to remove plaque. If the plaque is not removed immediately, minerals in saliva or gingival crevicular fluid can be deposited on the plaque, gradually allowing the plaque to mineralize and form tartar. Once tartar has formed, it cannot be removed by brushing or flossing, but must be removed with professional equipment.

This professional equipment is the ultrasonic scaler, which has not yet been invented by Tangning, but the principle has been designed and handed over to his subordinates for experimentation.

As with previous inventions, Downing will use the Telegraph and Nature to make concerted efforts in the two major fields of journalism and academia, so as to win the trust of the British people as quickly as possible. Toothpaste and toothbrushes are no exception. The new company will be called "British Everyday Chemicals Company".

In order to roll out the business as quickly as possible, Downing found the Retailers' Association in the City of London to absorb interested retailers as shareholders, and with their help, the sales of British daily chemical products do not have to worry, and these shareholders have to worry about it, he only needs to be responsible for production.

Downing and Eugenie were almost broken by Princess Victoria, although Downing used the excuse of observing the invention to fool the past, but Eugenie was still like in a dream, her mind was not clear, and Princess Victoria discovered a key point in Downing's description, and asked puzzledly: "Since sugar is very harmful in causing tooth decay, why is there a sweetener in toothpaste?" Isn't it a bit wrong to add harmful substances to enhance the taste? ”

What a smart princess, Tang Ning introduced happily: "Haha, I was discovered by you." Why is this sweetener called sweetener and not directly sugar? Because it's not sugar! It tastes sweet, but it's not sugar. The sweetener I use in my toothpaste has a name called 'sugar substitute', and as the name suggests, it's used to replace sugar. Its chemical name: aspartylphenylalanine methyl ester. Because it is not sugar, it does not promote the production of tooth decay and is not harmful. Hey? By the way, Europeans like to eat sugar so much, no matter what food you have, this is not good, it seems that I have to vigorously promote sugar substitutes. ”

Eugenie was so surprised that she forgot about her embarrassment: "Is there something that can replace the taste of sugar?" ”

Sikong Zero smiled: "Of course there is, the human body is imperfect, nothing is perfect, and there are a lot of things that fool people's taste." Sugar is a kind of energy, and the human body will convert excess energy into fat, too much sugar intake will make people fat, hey, Vicky, I think your mother needs sugar substitutes very much......"

Princess Victoria, nicknamed Vicky, showed a naughty look: "Ho, I'm going to tell my mother, Downing said that my mother is fat!" ”

Downing was taken aback, is it a great sin to slander the queen? He quickly put his index finger between his lips and made a panicked look of "boo".

After laughing, Eugenie, who had already regarded Tang Ning as omniscient, asked, "Is it fat?" Or is it better to be skinny? ”

Tang Ning: "Of course, the best fit of the slim nong, if you have to be fatter and thinner, for a person who does not worry about food and clothing, it is better to be thin." The biggest problem with the slimming point is that I am not hungry and afraid of the cold, because there is no fat wrap. Fat people have more fat, which will lead to easy blockage of blood vessels, and the prevalence of heart disease and cerebral hemorrhage will increase. ”

Princess Victoria admired: "Teacher Downing always explains things so well and profoundly, how good it would be if you were my teacher, those teachers of mine don't understand these scientific knowledge at all, and I always feel that Teacher Downing's knowledge is beyond the entire era......"

Downing smiled, her feeling was 100% correct. To further demonstrate the power of his knowledge, Downing also explained why things always have a degree, too little is not obvious, and too much often causes problems. Sugar substitutes, for example, are sweeteners that are broken down into phenylalanine, aspartic acid, and methanol in the digestive tract. It has been suspected that aspartic acid can cause brain damage, endocrine disorders, or tumors. Methanol is one of the raw materials of industrial alcohol, which can be metabolized into harmful substances such as formaldehyde and formic acid in the body. Phenylalanine is not suitable for all populations; Patients with congenital phenylalanine hydroxylase deficiency can cause intellectual development disorders called benzenyluria if taken by them.

However, sugar substitutes are 150 to 200 times sweeter than sucrose, and the content of harmful substances is relatively low when actually used. Phenylalanine and aspartic acid produced after the decomposition of sugar substitutes are amino acids that constitute proteins, which are found in meat, eggs and other foods, and their content is much higher than that of sugar substitutes.

We all know that seawater can not be eaten, but seawater is the raw material for salt production by drying salt, it can be seen that whether sugar substitutes are beneficial is a degree of problem, as long as it is controlled in a certain amount, it is safe, a good thing to control energy intake and protect teeth.

Princess Victoria finally remembered that Downing was robbing Napoleon III of her marriage, and the object of the robbery was the Countess of Teva, who was far away in the sky, although the status of the Emperor of France was extremely noble, but judging from the appearance of the countess obediently listening to the lecture now, she couldn't help asking: "Miss Montiro, may I ask, is your marriage decided?" ”

It turned out to be settled, and this time he had come to inform Downing personally, but when Eugenie took another look at the young and handsome little baron, he heard the bustling London he flickered and the telegraphs, electric lights, and bicycles in Paris because of the confrontation between the republicans and the new emperor of France...... Eugenie hesitated again, and now, she was also confused, and she didn't know what to do, so she could only reply to Princess Victoria, "I'm still thinking about ......"

Tang Ning smiled, this was his tactical victory, which had successfully reversed the countess's original determination to be the queen.