Human cells 7 years to replace it Don’t make excuses for the seven year itch (video) seaway

Human cells 7 years to replace it? Don’t make excuses for the "seven year itch" seven years is a hurdle, may let the couple break, this is known as "the seven year itch". The online forum has many questions: Why did it happen "seven year itch"? On this issue, there seems to be quite a scientific truth answer: "the body’s cells will metabolize, every three months will be replaced, with the old cells die, the birth of new cells. Due to the different time and spacing of different cell metabolism, all the cells will be replaced, it takes seven years. That is to say, physically, we are each other for seven years. You are you, but you are not you." But is it really the case? We’re going to start with the age of human cells measured with carbon 14. Professor Fries, a professor at the center for the study of cards at the Swedish Center for the study of cards in the 14 century, has been inspired by the fact that the concentration of carbon dioxide () can be used as a marker of cell age. Carbon 14 is a radioactive isotope of carbon, the impact of cosmic rays on the atmosphere, the half-life of 5730 years, the content in the atmosphere is relatively stable. However, from the middle of the 50s to the early 60s, many nuclear tests have been carried out on the ground, resulting in a significant increase in the concentration of carbon 14 in the atmosphere. In 1963, after a ban on the ground and no such a large number of sources of carbon 14. As a result of the diffusion and the exchange with the ocean water, the carbon content in the atmosphere is a rapid exponential decline of 14. For single cell, from the date of birth, DNA almost no occurrence of material exchange, which contains 14 carbon is at a relatively stable level (natural decay of carbon 14 within a few decades, very little) was equal to the atmospheric carbon concentration of 14. Therefore, the first measurement of the biological cell DNA carbon 14 content, and then with the atmosphere of carbon concentration curve corresponding to the 14, it will be able to launch the birth time of the cell. Human cells 7 years to replace it? Don’t make excuses for the "seven year itch" it is carbon 14 mark this tool, Professor Vries Don began to analyze some of the human body cell age. Due to the limited sample, his team can only temporarily focus on some areas of human cells. By analysis, they found that the average age of intestinal cells in adults was about 10.7 ± age of 3.6. However, previous studies have shown that intestinal epithelial cells have only 5 days of life due to adverse environmental conditions. The average age of the intestinal cells was about 15.9 years old, when Professor Vries Don removed these short-lived epidermal cells. In addition, they found that the average age of skeletal muscle is about 15.1 years old. As professor of neurobiology, Professor de Free Sean, the main purpose of this study is to study whether the cortical neurons of the cell regeneration. The study showed that the neurons in the occipital cortex were of the same age as the human race, but because the glial cells were updated, the mean age was lower than the age of the human being. Occipital cortex is considered to be the most prone to cell regeneration in the mammalian cerebral cortex. Therefore, the researchers believe that this study suggests that we相关的主题文章: