Two days later, the freshmen of Class 20 ushered in the first final exam of their college career.

Different from high school, the final exam of college is generally not too difficult, and it is all about some basic scoring questions, all of which depend on the student's mastery of knowledge points.

In addition to the compulsory courses, students of the Faculty of Biological Sciences also take basic compulsory courses such as "Bioethics", "Linear Algebra", "Inorganic and Analytical Chemistry", "Natural Sciences", "Organic Chemistry", "Advanced Mathematics", "College Physics", and "Introduction to Biology".

After several non-stop exams, the students were dizzy and didn't know what year it was.

However, for Chen Chen, there is nothing, others still need to carry cheat sheets for exams, but Chen Chen has already eaten dozens of textbooks, even if he directly takes the postgraduate examination, it is the level of sprinkling, let alone the final exam.

With several consecutive exams, Chen Chen has maintained the record of the first place in the paper, and he has also completely established the reputation of a top student in the 2nd class of biology.

After all, many people only handed in the papers after seeing Chen Chen write the exam papers, and when the invigilators picked up Chen Chen's test papers when they were bored and checked them, they were all surprised, not the kind of look that was so angry that they were almost angry, and the error rate was obviously 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 could not be said.

At the request of Li Bo and Zhou Jie, Chen Chen had to copy a copy of the answer to the multiple-choice question to the two of them every time he finished answering the question, and the price was that the two of them had to make boiling water for Chen Chen for a whole semester from the next semester.

After signing this humiliating and unequal treaty, the two of them looked at Chen Chen with a certain complicated expression every time, but as soon as they arrived at the examination room, that complexity changed to eagerness and piety in the face of a savior.

In this kind of pain and eagerness, Li Bo and Zhou Jie secretly vowed that they must study hard at the beginning of the next semester and strive to turn over as serfs and sing before their sophomore year.

After a few days of dark exams, finally, the freshmen of Shangdu Jiaotong University ushered in the first vacation of their college careers, and countless students who had left their hometowns cheered and embarked on the journey home.

As the campus gradually became deserted, after Chen Chen and Wang Wei sent Li Bo and Zhou Jie away, they made an appointment to meet Xia Yin and prepare for the experiment.

In an empty teacher, 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 he could never forget it.

After a while, there was a brisk footstep outside the hallway, and then a girl with long hair in a shawl appeared in the doorway.

The girl has a pair of bright eyes, clear and clear, and when she sees the two people in the classroom, she smiles lightly, and the girl's unique youthful atmosphere overflows.

"You ......"

Seeing the girl walk into the classroom, Wang Wei hurriedly stood up and said in surprise, "Little sister, you are Xia Yin, right?" ”

"Hello, I am."

Although he didn't wear that pair of black-framed glasses, changed a pair of contact lenses, and even painted makeup, these details were as if they didn't exist in Chen Chen's brain.

With Chen Chen's brain supplement, even if the woman in front of him is reduced to a form without clothes, it is so eary.

"What's the costume?" Chen Chen pretended to be surprised.

"After all, it's a holiday, so it's not too much time to clean up, right?" Xia Yin pretended to be annoyed, "Isn't it pretty?" ”

"It's beautiful, I thought it was that kind of rich ...... Ahem, ahem, ahem! ”

Wang Wei just wanted to speak, but then realized something and coughed wildly.

After introducing the two to each other, Chen Chen led the topic to the topic, "This time, there are three experiments that I have tentatively planned, all of which are related to autologous stem cells. ”

As he spoke, Chen Chen took out a thick book of printed materials from his schoolbag and handed it to Xia Yin, "Stem cells, a type of cell in the human body that has infinite self-renewal ability, and can differentiate into at least one type of offspring cell. ”

"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, fat cells, and so on."

"Stem cells in the human body work every day, hair grows, nails grow, and every day new cells replace senescent cells, and the source of these new cells is all kinds of stem cells in the human body."

"And my first experiment was a therapeutic experiment on brain damage caused by neural stem cells."

Chen Chen explained, "Neural stem cells, as the name suggests, are a kind of adult stem cells that can repair nerves, and the principle of surgery is that after implantation in the human body, it will stimulate the body's own stem cells to automatically secrete cell growth factor, a small molecule protein with a wide range of biological activities, so as to repair cranial nerves. ”

As the name suggests, 'autologous' is derived from the stem cells in one's own body, through the extraction of one's own stem cells through external culture and growth, and then injected into one's own body, this kind of stem cells from oneself does not have compatibility problems, avoids transplant rejection, is the best choice."

"In this experiment, we need to make a brain damage model, so it is better to use SD rats than Kunming mice, after all, larger animals are easier to operate."

Speaking of this, Chen Chen's expression gradually became solemn, "...... As for the autologous neural stem cells required for the experiment, I will use two methods to obtain them: first, artificial cultivation; 2. Extraction from the body of the replica by cloning. ”

"Clone?"

Wang Wei was taken aback, raised his head and said, "Do you want to conduct two batches of experiments, which neural stem cell is more effective?" ”

"That's right, that's it."

Chen Chen snapped his fingers, "Although the outside world has always boasted that stem cells are miraculous, claiming to multiply infinitely and never age, etc., but in fact, if human stem cells can really multiply indefinitely, why do human beings still age and die?" So I wanted to see if there would be a difference in efficacy between artificially cultivated stem cells and cloned new stem cells, since they are all autologous stem cells. ”

"Then why not take the inducement approach?"

Xia Yin sat down in front of Chen Chen, holding her chin with one hand, "The experiment is ultimately for humans, since you want to compare the differences between stem cells, it is more practical to use the stem cells formed by directional induction differentiation technology, right?" ”

"The preparation technology of directed induced stem cells is too complex and costly."

"Moreover, the technology is not mature, and the induced stem cells have a risk of tumorigenesis and immune rejection. ”

"We can also try cloning other animals, such as rabbits." Wang Wei proposed.

"Of course, rabbits can try, but don't forget the cost and time issues, the gestation cycle of SD rats is 20 days, and rabbits are twice as long, which limits our experimental materials."

"Well, I didn't think about it." Wang Wei looked apologetic.

Chen Chen continued, "In the second experiment, I will destroy the spinal nerves of several rats to make them paraplegic without life-threatening, and then also grow stem cells to see if I can restore the rats' mobility in this way. ”

"And then, the last experiment, and what I think is the most important one......"

Chen Chen's expression gradually became solemn, "The first two experiments are nothing, they have been done all over the world, but the third one is different, it is related to rebuilding the immune system." ”