Two days later, the freshmen of grade 20 ushered in the first final exam of their college career.
Unlike high school, final exams in universities are generally not too difficult. They are all based on basic questions, which all depend on students' mastery of knowledge points.
In addition to the required courses for majors, students in the School of Biological Sciences also need to take exams such as "Bioethics", "Linear Algebra", "Inorganic and Analytical Chemistry", "Natural Science", "Organic Chemistry", "Advanced Mathematics", and "College Physics" , "Introduction to Biology" and other basic compulsory courses.
After several non-stop exams, the students were all dizzy and wondered what year it was.
But for Chen Chen, it didn't matter. Others still needed cheat sheets for exams, but Chen Chen had already thoroughly read dozens of textbooks. Even if he took the postgraduate entrance examination directly, it would be a waste of time, let alone the final exam.
As Chen Chen maintained the record of first place in the exams for several consecutive exams, he also completely established his reputation as a top student in Class 2 of the Biology Department.
After all, many people turned in the exam paper after seeing Chen Chen fill it up, and when the invigilators picked up Chen Chen's exam paper and looked at it when they were bored, they all had surprised expressions on their faces, instead of looking like they were so angry that they almost passed away. , obviously the error rate is not high.
So, after another exam, Li Bo and Zhou Jie forcibly dragged Chen Chen back to the dormitory and made a secret transaction that cannot be said.
At the request of Li Bo and Zhou Jie, every time Chen Chen finished answering a question, he would give them a copy of the answer to the multiple-choice question. The price was that they would have to support Chen Chen for a whole semester starting from the next semester.
After signing this humiliating and unequal treaty, the two of them had some complicated expressions every time they looked at Chen Chen. However, once they arrived in the examination room, the complexity turned into a savior-like eagerness and enthusiasm. Pious.
Amidst this pain and ardor, Li Bo and Zhou Jie secretly vowed to study hard starting from the next semester and strive to become serfs and sing before their sophomore year.
After several days of exams in the dark, the freshmen of Shangdu Jiaotong University finally ushered in the first vacation of their college careers. Countless students who had left their hometowns cheered and embarked on their journey home.
As the campus gradually became deserted, Chen Chen and Wang Wei saw off Li Bo and Zhou Jie, and then made an appointment with Xia Yin to meet at a place to prepare for the experiment.
In an empty classroom, Wang Wei was looking at the thick experimental materials, and Chen Chen was opening a textbook on cell biology.
Although Chen Chen's expression was very casual, every time he turned a page, all the knowledge on that page would be permanently engraved in Chen Chen's mind and could never be forgotten again.
After a while, there were brisk footsteps outside the corridor, and then a girl with shawl-long hair appeared at the door.
The girl had a pair of bright eyes, bright and clear. When she saw the two people in the classroom, she smiled softly, and the girl's unique youthful atmosphere overflowed.
"Who are you… "
Seeing the girl walk into the classroom, Wang Wei quickly stood up and said in surprise, "Miss, are you Xia Yin?"
"Hello, I am."
Although he didn't wear the black-rimmed glasses, changed to a pair of contact lenses, and even put on makeup, these details were as if they didn't exist in Chen Chen's mind.
Based on Chen Chen's imagination, even if the woman in front of him was restored to her undressed form, it would still be sober.
"Why are you dressed like this?" Chen Chen pretended to be surprised.
"After all, it's a holiday, so it's not too much to squeeze in some time to tidy up, right?" Xia Yin pretended to be angry, "Isn't it nice?"
"She's quite beautiful. I thought she was that kind of rich...cough cough cough cough!"
Just as Wang Wei was about to speak, he realized something and started coughing crazily.
After introducing the two to each other, Chen Chen brought the topic to the main topic, "This time, I have tentatively planned three experiments, all related to autologous stem cells."
With that said, Chen Chen took out a thick printed material from his school bag and handed it to Xia Yin, "Stem cells are a type of cell in the human body that have unlimited self-renewal capabilities and can differentiate into at least one type of daughter cells. "
"For example, hematopoietic stem cells can differentiate into red blood cells, white blood cells, platelets, etc.; skeletal mesenchymal stem cells can differentiate into bone cells, chondrocytes, muscle cells, adipocytes, etc.,"
"Stem cells in the human body are working every day. Hair keeps growing, nails grow, and new cells replace aging cells every day. The source of these new cells is the various stem cells in the human body."
"And my first experiment is about the therapeutic effect of neural stem cells on brain injury."
Chen Chen explained, "As the name suggests, neural stem cells are a type of adult stem cell that can repair nerves. The principle of the surgery is: after being implanted into the human body, it will stimulate the body's own stem cells to automatically secrete cell growth factors - a type of small molecules with a wide range of biological activities. protein to repair brain nerves.”
"Stem cells can be divided into 'autologous' and 'allogeneic'. As the name suggests, 'autologous' are stem cells derived from one's own body. By extracting one's own stem cells, cultivating and growing them from the outside, and then injecting them into one's own body, this kind of stem cells originating from one's own body Stem cells have no compatibility issues and avoid transplant rejection, making them the best choice."
"For this experiment, we need to create a brain injury model, so it is better to use SD rats than Kunming mice. After all, larger animals are easier to operate."
At this point, Chen Chen's expression gradually became solemn, "... As for the autologous neural stem cells required for the experiment, I will obtain them in two ways: first, artificial cultivation; second, extract them from the replicator through cloning."
"clone?"
Wang Wei was suddenly startled, raised his head and said, "Do you want to conduct two batches of experiments to compare which neural stem cells are more effective?"
"That's right, that's it."
Chen Chen snapped his fingers, "Although the outside world has been touting stem cells as magical, claiming to proliferate infinitely and never age, in fact, if human stem cells can truly proliferate infinitely, why do humans still age and die? So I want to see Look, since they are all autologous stem cells, will there be any difference in efficacy between artificially cultivated stem cells and cloned new stem cells?"
"Then why not use induction?"
Xia Yin sat in front of Chen Chen and held her chin with one hand. "The experiment is ultimately for humans. Since we want to compare the differences between stem cells, it is more practical to use stem cells formed by directed induction differentiation technology, right?"
"The preparation technology of directed induced stem cells is too complicated and the cost is high."
Chen Chen explained, “Moreover, this technology is not mature, and the induced stem cells have the risk of tumor formation and immune rejection.”
"We can also try cloning other animals, such as rabbits." Wang Wei suggested.
"Of course you can try it with rabbits, but don't forget the issues of funding and time. The pregnancy cycle of SD rats is 20 days, while that of rabbits is twice as long. This limits our experimental materials."
"Okay, I didn't think carefully." Wang Wei looked apologetic.
Chen Chen then continued, "In the second experiment, I will destroy the spinal nerves of several rats, making them paraplegic at a high level without endangering their lives, and then also cultivate stem cells to see if I can restore the rats' movements in this way. "
"Then, there is the last experiment, and it is also the most important experiment in my opinion... "
Chen Chen's expression gradually became serious, "The first two experiments are nothing, they have been done all over the world, but the third one is different and has to do with rebuilding the immune system."