字幕列表 影片播放 列印英文字幕 It's AumSum Time Can you guess the title of my next video? Hurry up. Write your guess in the comments section below. Why is it hard to cure HIV/AIDS? HIV or human immunodeficiency virus infects the cells of immune system. Causing them to produce more copies of the virus and then eventually die. When too many immune cells of your body die and our immune system is unable to fight off diseases. Then we are said to have AIDS or Acquired immunodeficiency syndrome. Now, coming back to the question. It is hard to cure HIV or AIDS because HIV has the ability to mutate extremely quickly. Hence, a drug which is somewhat effective on a patient suffering from HIV or AIDS. Might not work on another patient because of the mutated HIV. Now, there are certain antiretroviral drugs that prevent the cells from producing new copies of HIV. Thus controlling the HIV levels in our body. But, it is hard to completely eradicate HIV because the virus integrates its DNA into our cell's DNA. Hence, if we stop taking the drugs, the DNA of the virus can again cause the cell to produce copies of the virus. Thus, we are unable to control the level of HIV infected cells in our body. What happens if a plane is struck by lightning? It will start glowing like a disco ball. No. Lightning is a massive flow of charge which carries thousands of volts of electric current. Thus, it is extremely fatal for living beings and can damage anything that comes in its way. Yes. It is really terrifying. Now many times, airplanes get caught in a heavy lightning storm. However, airplanes are designed to handle the lightning strikes. The outer skin of most planes is primarily made of aluminum. Aluminum is a good conductor of electricity. When lightning hits the airplane, the electric current travels through the outer skin of the plane. It does not pass into the airplane. Eventually, it exits off through another extremity, such as tail. Thus, the airplane and the passengers within remain protected. Topic: Oxidation. Why do copper vessels turn green? What a beautiful copper statue. Have you made it? Good job. But why did you use copper to make the statue? It will turn green after a while. No. It will not happen immediately. It will take some time. Look. I had told you earlier. Do you know why this happened? This happened because of oxidation. Do you know what oxidation is? It is a process in which a substance gains oxygen. When the copper statue was exposed to moisture and air for a long period of time, it started to get oxidized. In the oxidation process, its color started changing to blackish brown and then eventually into green. The green layer of color appeared because of a number of chemical reactions. That took place when exposed to moisture and air. This green layer formed is called patina. No. Don't worry. Patina does not damage the statue. Patina is just a layer on top of the metal. It protects the copper beneath from further oxidation, thus keeping the properties of copper intact. What causes heart attacks? High electricity bills. No. A heart attack or myocardial infarction is the complete blockage of blood flow to a part of the heart. Causing its muscle cells to die. So sad. A network of blood vessels called coronary arteries. Continuously supply oxygenated blood to muscle cells of heart to keep them working properly. However, due to bad lifestyle choices and stress. Cholesterol and fats start building in these arteries, reducing blood flow to the muscle cells. This buildup is called plaque. Plaque is the main culprit behind most heart attacks. So, shall we put plaque in jail? Just listen. When plaque ruptures, a blood clot forms around it causing the artery to get completely blocked. The blood then cannot pass further to that part of the heart. Thus, due to lack of oxygen, the muscle cells in that part die. This condition is called a heart attack. Why do we crave sugar? Because sugar contains all the essential nutrients. No. Sugar is found in many food items like chocolates, cakes, ice-creams, etc. They are really tempting. Indeed. But, when we eat such sugary foods, the sweet-sensing taste buds in our tongue send signals to the brain. In the brain, these signals activate the reward system due to which neurotransmitters like dopamine are released. Dopamine gives us pleasure and makes us feel good. As it makes us feel good, we tend to eat more sweet-sugary foods to get the same feeling. Thus, sugar acts like a drug, making us addictive and thus, causing cravings. However, note that excess sugar is not good for mental as well as physical health. Hence, we can use natural sweeteners like jaggery and honey which don't cause harm and satisfy our cravings.