Interpretation of the 2021 Nobel Prize in Natural Sciences

Source: China Youth Daily

2021 Nobel Prize in Physiology or Medicine –

Solve the mystery of human perception

Qiu Chenhui, reporter of China Youth Daily and China Youth Network

Imagine that on a hot summer day, when you walk barefoot through the lawn, you can feel the heat of the sun, the touch of the wind, and every blade of grass under your feet. These impressions of temperature, touch, and movement are something that almost everyone can feel.

But where did all this hot or cold, hard or soft, ache or pressure come from? What nerves cause these perceptions, and how are they initiated? Humans don't know.

This is the problem that the 2021 Nobel laureates in physiology or medicine have to address. On October 4, Beijing time, the award was announced, awarding American scientists David Julius and Ardem Patapoutian for their contributions to "discovering temperature and haptic receptors".

The Nobel Prize committee argues that the breakthrough discoveries of the two scientists led to an intensive series of research activities that rapidly accelerated understanding of how the nervous system perceives heat, cold and mechanical stimuli.

How do the eyes detect light, how do sound waves affect our inner ear, and how do different compounds interact with the receptors in our nose and mouth to produce a sense of smell and taste? For thousands of years, one of the great mysteries facing humanity has been how we perceive our environment.

In the 17th century, the philosopher René Descartes envisioned that different parts of the skin could be connected to the brain. Through this mechanism, a foot that touches an open flame sends mechanical signals to the brain. Later discoveries showed that there are specialized sensory neurons in the human body that can record changes in our surroundings.

Scientists Joseph Erlanger and Herbert Gasser discovered that there are different types of sensory nerve fibers in the body that respond to different stimuli, such as painful and non-painful touches, for which they both won the 1944 Nobel Prize in Physiology or Medicine.

Since then, scientists have shown that nerve cells have been highly specialized to detect and transducer different types of stimuli, allowing humans to subtly perceive their surroundings. For example, people can feel the difference in surface texture through their fingertips, and they can also distinguish between pleasant warmth and painful burning.

Still, scientists have one fundamental question that hasn't been solved: How do temperature and mechanical stimuli be converted into electrical impulses in the nervous system?

In the late 1990s, David Julius saw a "dawn of victory" when he analyzed how the compound capsaicin triggered a "burning sensation upon contact with chili peppers."

At that time, scientists already knew that capsaicin could activate nerve cells that cause pain sensations, but how the chemical worked was still an unsolved mystery.

Julius and his colleagues created a database of millions of DNA fragments that correspond to genes expressed by sensory neurons that respond to pain, heat and touch. After a lot of work and painstaking searching, they identified a gene that makes cells sensitive to capsaicin— the body's ability to feel capsaicin— and it was discovered!

Further experiments by Julius's team showed that the gene they found encoded a new ion-channel protein, the capsaicin receptor, which was later named TRPV1.

The Nobel Prize committee believes that the discovery of TRPV1 is considered a major breakthrough, which opens the way for the unveiling of other temperature-sensing receptors.

However, as the mechanism by which the human body perceives temperature is constantly revealed, the scientific community remains unclear about the mechanism by which the human body converts mechanical stimuli into a sense of tactile pressure.

At the Scripps Institute in La Jolla, California, PATAPULTIAN and his colleagues discovered a new, mechanically sensitive ion channel and named it Piezo1 in the Greek word for "stress." They also identified a gene similar to Piezo1 and named it Piezo2, which is at a high level of expression in sensory neurons. Through further research, Piezo1 and Piezo2 are ion channel receptors that exert pressure on cell membranes to directly activate both receptors.

The Nobel Committee gave this assessment: The breakthrough discovery of this year's Nobel Laureate in Physiology or Medicine has given people an understanding of how cold, heat, and mechanical forces trigger nerve impulses, as well as the mechanisms by which humans perceive and adapt to external stimuli. Of course, numerous studies based on this finding are still underway, and researchers are working to elucidate their function in various physiological processes, which are expected to be widely used in the treatment of many diseases.

2021 Nobel Prize in Physics ——

Global warming can be reliably predicted

Yang Jie, trainee reporter of China Youth Daily and China Youth Network

Earth's climate is a complex system that is vital to humanity.

How does the increase in carbon dioxide levels in the atmosphere lead to an increase in the Earth's surface temperature? How does the Earth's climate change? How will humans affect it?

All this is related to the "predestined" thing to find a scientific prediction scheme.

At about 17:45 Beijing time on October 5, the 2021 Nobel Prize in Physics was announced, awarding Syukuro Manabe, a senior meteorologist at Princeton University in the United States, and Klaus Hasselmann, a professor at the Max Planck Institute of Meteorology in Hamburg, Germany, for "physical modeling of the Earth's climate, quantifying variability and reliably predicting global warming", and the other half was awarded by Professor George W. Bush, University of Rome, Italy. Giorgio Parisi shared, "Discovering the interaction between disorder and fluctuations in physical systems from the atomic to planetary scale." ”

The claim from the Nobel Prize committee is that the 3 laureates shared this year's Nobel Prize in Physics for their research on chaotic and apparently random phenomena. Hidero Makoto and Klaus Hasselmann laid the foundation for us to understand Earth's climate and how humans affect it. George Parisi was awarded for his revolutionary contributions to disordered materials and the theory of stochastic processes.

Svante Arrhenius, the 1903 Nobel Laureate in Chemistry, unraveled important mysteries about the effects of carbon dioxide. He concluded that if the level of carbon dioxide in the atmosphere were halved, it would be enough to put the planet into a new ice age. And vice versa – doubling the amount of carbon dioxide would raise temperatures by 5-6 degrees Celsius, a result that is somewhat strikingly close to current estimates.

By 1960, Hidero Manabe led the development of a physical model of the Earth's climate, becoming the first to explore the interaction between the radiation balance and the vertical transport of air masses. His work laid the foundation for the development of current climate models.

To make the calculations manageable, Hidero Chose to reduce the model to one dimension, i.e. a vertical column 40 kilometers from the atmosphere. Models found that the effects of oxygen and nitrogen on surface temperatures were negligible, while carbon dioxide had a pronounced effect: when carbon dioxide levels doubled, global temperatures rose by more than two degrees Celsius.

Hidero Makoto obtained a pioneering model for understanding the effects of carbon dioxide, which was published in 1975 and became another milestone on the road to understanding the secrets of climate. In 1950, Klaus Hasselmann, a young physics phD student in Hamburg, Germany, was working on fluid dynamics, developing observational and theoretical models of waves and ocean currents.

Klaus Hasselmann then moved to California to continue his oceanographic research, met charles David Keeling and other colleagues, and joined them in a pastoral choir. Unbeknownst to Klaus Harcelman, in his later work, he would often use a Keeling curve that shows changes in carbon dioxide levels.

In the study, Klaus Hackellman created models that link weather and climate, solving the question of why climate models remain reliable in the face of variable and chaotic weather.

The model clearly shows the accelerated greenhouse effect: since the middle of the 19th century, the amount of carbon dioxide in the atmosphere has increased by 40%. Temperature measurements show that global temperatures have increased by 1 degree Celsius over the past 150 years.

His method has been used to show that the rise in atmospheric temperatures is due to carbon dioxide emissions from humans.

Another 10 years later, around 1980, Giorgio Parisi discovered hidden patterns in disordered complex materials that made it possible to understand and describe many different, apparently completely random materials and phenomena. This can be applied in fields such as physics, mathematics, biology, neuroscience, and machine learning. His discovery is one of the most important contributions to the theory of complex systems.

"This year's Nobel Prize shows that our understanding of the climate is based on solid scientific foundations, based on rigorous analysis of observations. This year's winners all contribute to our deeper understanding of the properties and evolution of complex physical systems. Nobel Committee chairman of physics Thors Hansson said.

2021 Nobel Prize in Chemistry –

Turn molecular construction into art

Intern Sun Shaoqing, reporter of China Youth Daily and China Youth Network, Ye Yuting

Constructing molecules is a difficult art.

On October 6, 2021, Benjamin List and David W.C. MacMillan were awarded the 2021 Nobel Prize in Chemistry for developing a new tool for precise molecular construction, organic catalysis, which has had a huge impact on drug research. The Nobel Prize Committee commented that [they] promoted the development of asymmetric organic catalysis.

People are not unfamiliar with the concept of "catalyst". In the middle school chemistry experiment, manganese dioxide has been used as a catalyst to decompose hydrogen peroxide to prepare oxygen at room temperature. Without the catalytic effect of manganese dioxide, it may be necessary to heat hydrogen peroxide to a boil to achieve the same effect. Therefore, catalysts are a common tool in chemical reactions. Chemists have long believed that there are only two types of catalysts in principle: metals and enzymes. As early as 2001 and 2018, the Nobel Prize in Chemistry has recognized six scientists who have made outstanding contributions to the study of these two types of catalysts.

In 2000, Benjamin Liszt and David McMillan independently developed a third catalyst, the organic small molecule catalyst, which has a stable carbon atom framework that can attach more active chemical groups to achieve higher catalytic efficiency. Many kinds of amino acids are better performance of organic small molecule catalysts, compared to expensive, fragile, pollution metal catalysts, organic small molecule catalysts are inexpensive, easy to extract, wide adaptability, therefore, once found has attracted wide attention from the academic community.

The asymmetric organic catalysis developed by Liszt and McMillan solves the problem of efficient synthesis of chiral organic compounds. There are two chiral molecules present in organic matter, usually divided into left-handed and right-handed. When synthesizing, these two molecules generally appear at the same time. Since the chemical properties of the two chiral molecules are usually different, one only wants to get one chiral molecule.

For example, for some special drugs, it may be that left-handed molecules are active ingredients, but right-handed molecules are harmful components. People have made great efforts to remove this component, and using asymmetric organic catalysis, many reactions have good specificity, so that the synthesis result is basically only a chiral molecule. Johan Qvist, chairman of the Nobel Committee on Chemistry, said: "This concept of catalysis is both simple and ingenious, and in fact many people are wondering why we didn't think of it earlier. ”

Organic small molecule catalysts also greatly simplify the synthesis process of certain molecules. Taking a natural molecule strychnine as an example, in 1952, when scientists first realized artificial synthesis, 29 different chemical reactions were used, and the conversion rate of raw materials was only 0.0009%. In 2011, with the help of organic small molecule catalysts, it took only 12 steps to achieve artificial synthesis, and the production efficiency was increased by 7,000 times.

Of course, the relevant literature also pointed out some shortcomings of the current organic small molecule catalysts, although its wide range of uses, low price, stable structure, can meet the needs of green chemistry, but compared with metal catalysts, the catalytic efficiency of organic small molecule catalysts is still slightly inferior. Therefore, how to design more efficient organic small molecule catalysts is still the focus of research in the current academic community. In addition, organic small molecule catalysts have not yet been applied on a large scale in industrial production. How to develop organic small molecule catalysts suitable for large-scale, industrial production is also a common challenge faced by chemists.

According to statistics, since the establishment of the Nobel Prize in Chemistry in 1901, in addition to certain special years, it has been awarded 113 times so far, and a total of 188 scientists have won this honor. Among them, the youngest Nobel Laureate in Chemistry is Joliot Curie, the daughter of the famous scientist Marie Curie, who won the prize in 1935 at the age of 35. The oldest Nobel laureate in chemistry is John Goodenough, who was 97 years old when he won the prize in 2019.

In addition, the only scientist to win the Nobel Prize in Chemistry twice was Frederick Sanger, who won the prize in 1958 and 1980. In addition, two scientists have won other Nobel Prizes: Marie Curie, who won the Nobel Prize in Physics in 1903 and the Nobel Prize in Chemistry in 1911; And Linus Pauling, who won the Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize in 1961. It is worth mentioning that Linus Pauling is also the only winner who has won both solo awards.