I am a super cop

Chapter 808 Lefort Aqua regia

"Interdisciplinary team?" Lu Weiwei was stunned for a moment, and said involuntarily: "The name sounds amazing. Does it mean that not only forensic doctors, but also other types of police and personnel from other professions can participate?"

Forensic Liu nodded slightly: "That's probably what it means, because in Jiangnan City, we still need to strengthen training in diatom detection, otherwise Gao Chuanfeng would not have asked such a stupid question."

"Uh." Suddenly feeling that he was shot while lying down, Gao Chuanfeng felt that his whole body was not well.

Gu Chen frowned slightly, and tentatively said: "To form such an interdisciplinary team, it is necessary to mobilize key personnel. The team members must have forensics, materials, chemistry, etc. Biology."

"Yes, what you said is very correct." Liu Fayi fully agreed with Gu Chen's opinion, and said involuntarily:
"With this interdisciplinary team, the next step is to focus on overcoming three difficult problems."

Police Officer Wang didn't understand very well, so he asked for advice: "Forensic Doctor Liu, can you be more specific? Which three problems?"

After completing the phased tests in hand, Forensic Doctor Liu turned back and said, "The first thing is to digest the tissue and keep the shell of the diatom."

"Secondly, diatoms need to be enriched, and the third is process pollution prevention."

Seeing everyone bowed their heads to think, Liu Fayi said again: "These seemingly simple steps, but in fact, if they are not properly performed during the process, many problems will arise."

"For example, for diatom detection technology, this kind of research is not new. As early as 2003, the relevant team purchased an electron microscope for the study of abnormal particles in drowned corpses."

"They used foreign objects in the corpse to determine the cause and location of death. During the experiment, these forensic doctors were pleasantly surprised to find that the actual application of diatoms has better results, but it also has flaws."

"Master, don't talk about the advantages, let's talk about the disadvantages." Forensic assistant Gao Chuanfeng was also a little impatient.

Liu Fayi glanced at him and said, "If it's a shortcoming, it's an operational flaw."

"Operational defects?" Gao Chuanfeng froze for a moment, then quickly frowned and asked, "Which specific aspects are you referring to?"

"In actual operation, the technical effect of diatom inspection may not be satisfactory." Gu Chen said.

Forensic Liu nodded slightly: "That's right, the operational defect I'm talking about refers to this, because the effect is relative."

Lu Weiwei was thoughtful, and also asked Liu Forensic Doctor: "Why is that, what is the reason?"

"This..." Liu Fayi just wanted to speak, but he glanced at Gu Chen beside him, so he asked Gu Chen directly: "This question, Gu Chen, what do you think?"

"I think it's a pollution problem." Gu Chen answered directly: "Pollution is a big problem, and the detection rate is low. Third, standards cannot be formed."

Liu Fayi smiled slightly: "Gu Chen, continue talking."

"Yes." Gu Chen nodded silently, and after a few seconds of silence, he explained to everyone:

"Maybe for this kind of test, a famous master can do it, but he can do it, others can't, that is to say, there is no repeatability."

"But there is no repetition, it can only be called experience, not science."

"That's very well said." Forensic Doctor Liu agreed with Gu Chen's opinion very much, and said involuntarily: "Let's take myself as an example. Maybe for testing, with my own rich testing experience, I may be able to succeed."

"But if, I mean if, leave it to Gao Chuanfeng and other assistants to do it."

"In terms of experience, they are definitely not as good as me. The consequence of lack of experience is that the detection is not ideal and the accurate effect cannot be achieved."

"So this is what Gu Chen said, something without repetition can only be called experience, not science."

"But to solve this problem, we actually took a lot of detours."

"Yes." Gu Chen felt the same way, nodded slightly, and said, "Over the years, the most traditional way to find diatoms... is to extract tissue samples from corpses."

"After the extraction, the tissue is digested with a mixed acid, followed by a series of procedures such as centrifugation and separation, and finally extracted and made into glass slides."

"But after it's over, you have to use an optical microscope to observe, and finally you can look for traces of diatoms."

After a pause, Gu Chen said again: "But such a traditional extraction method has many problems."

"Because the traditional strong acid digestion method is open, during the digestion process... there is a danger of strong acid spraying out and burning the human body."

"Moreover, during the digestion process of strong acid and test materials, nitrogen dioxide and malodorous gases are released, which are easy to pollute the environment."

"Is there still so much trouble?" Police officer Wang couldn't understand what Gu Chen was talking about, after all, these things were beyond his own understanding.

Gu Chen nodded slightly, and continued: "Yes, it is quite troublesome, and this is also a disadvantage."

"In addition, traditional digestion generally requires repeated centrifugation before making slices for observation. About 30% of diatoms will be lost after one centrifugation, resulting in a low recovery rate of diatom extraction."

"In addition, the magnification of traditional optical microscopes is limited, relying on manual search and analysis work is intensive, and for micro-diatoms, it is easy to miss detection or cannot accurately identify its species."

"However, the characteristics of diatoms determine that it is still the 'gold standard' for the diagnosis of drowning. Through the analysis of diatoms, not only can a more direct judgment be made on the cause of death, but it can also point to the possible place of drowning."

"Yes, what Gu Chen said is very good." Forensic Doctor Liu, who has completed the next step of testing, is performing various operations in his hands, and said with his back to everyone:
"It is precisely because the traditional method of detection...has great disadvantages, so overcoming difficulties and improving technology can highlight the effectiveness."

"From this point of view, the colleagues in Yangcheng have indeed done a good job."

"So, how can we upgrade the existing diatom detection methods to make them practical?"

"Colleagues in Yangcheng, they have formed an 'interdisciplinary team' composed of technical backbones in the criminal department. In addition to forensic science, there are also materials science, chemistry, and biology. .”

"It is precisely because of such an interdisciplinary team with many backbone talents that we can make breakthroughs in digesting tissues, retaining diatom shells, enriching diatoms, and preventing process pollution."

Looking back at the crowd, Liu Fayi took a deep breath and said with a light smile: "In order to do experimental research, people often arrange experiments at night and in the wild just like us."

"Because we do research on drowning, we can't attract too much attention from the society, let alone affect everyone's daily life."

"Sometimes they would go to the lake to do research in the middle of the night, and as far as the beach, they would call sanitation vehicles to transport the lake water back to the laboratory for research."

"It is precisely because of this spirit of overcoming difficulties that people have explored technology by technology, from traditional strong acid digestion to centrifugal enrichment, to light microscopy, and to microwave digestion to filter membrane enrichment. , to scanning electron microscopy."

"In this way, the time for processing diatoms... can be shortened by a full three-quarters, and the positive rate of diatoms has also increased from 28% to 97%, which is a qualitative leap."

"That's right." Gu Chen smiled slightly, and continued to supplement Liu's forensic doctor's remarks: "Actually, microwave digestion is used instead of traditional strong acid digestion, which shortens the processing time, reduces environmental pollution, and is fast and effective. Thoroughly."

"The use of membrane filtration not only replaces traditional centrifugation, but also greatly improves the recovery rate of diatom extraction."

"And the diameter of the filter pores on this filter membrane is only 0.45 microns."

Glancing at everyone, Gu Chen deliberately reminded: "Everyone, please pay attention, it is only 0.45 microns, which is enough to stop diatoms in nature."

"And using an electron microscope instead of a traditional light microscope."

Lu Weiwei nodded silently when she heard the words, and asked Gu Chen: "I know that the detection effect of the electron microscope is much higher than that of the traditional optical microscope."

"But Junior Brother Gu, can you give a specific comparison so that we can have a more intuitive understanding?"

"Cough." Faced with Lu Weiwei's curiosity, Gu Chen coughed twice, and adjusted his tone:

"Then let me tell you this. The magnification of traditional optical microscope inspection is only about 400 times, and human eyes are still needed for identification."

"The electron microscope can perform automatic scanning, which is fast and accurate, and easy to automate."

"In terms of technology alone, the two are not at the same level."

"So that's how it is. Wouldn't that be simpler and more accurate?" Lu Weiwei stretched her left finger with her right hand and said, "Automatic scanning is fast and accurate, and it's easy to automate. Then anyone can do it too?"

"That's right." Liu Forensic Doctor smiled at Lu Weiwei and said, "It's a coincidence that we have one in our laboratory, so the detection is not complicated. The key is that his colleagues in Yangcheng paved the way for us."

"Yes." Gu Chen walked to an electron microscope and said involuntarily:
"I remember that the scientific research team in Yangcheng has achieved remarkable results in a series of research on scientific instruments and scientific methods."

"And they have also published many papers in top international forensic journals, and have been invited to give academic reports at the International Forensic Science Conference for many years in a row."

"In addition, they also obtained 4 invention patents and 3 utility model patents."

"Hey." Hearing this, Forensic Doctor Liu said enviously, "They are mainly an interdisciplinary professional team composed of key personnel."

"Actually, I also had the idea of ​​setting up a research project on this topic many years ago, but at that time I was not highly qualified and not very well-versed in the world. It was simply impossible to find such a backbone interdisciplinary team member."

"And even if I have interdisciplinary team members, and all of them are backbones, if the scientific research funds are not in place, it will be difficult for this project to make a difference."

Seeming to be regretful, Fayi Liu also took a deep breath after hearing Gu Chen praise his colleagues in Yangcheng, trying to calm down.

Everyone seemed to feel the helplessness of Liu Fayi, and they could only look at each other without daring to make a sound.

Liu Fayi glanced at the crowd behind him, and suddenly pouted and laughed at himself: "Actually, to complete such a major project, not only the investment of talents, but also the investment of capital, software and hardware equipment is required."

"And even if you form a professional interdisciplinary team, it will take years to do repeated demonstration and research, and you may not necessarily achieve results in the end."

"Therefore, obtaining an upgraded testing plan depends not only on the ability of the team, but also sometimes on the determination of the higher-ups, whether they are willing to invest heavily and allocate resources to scientific research projects."

"And scientific research projects are often the most expensive. They are not as fast as buying and selling real estate, and they can't produce results quickly."

"It's okay if the supervisor is patient, but I'm afraid that the leadership will change, and the follow-up of the project will be cut off for other expenses."

"Anyway, it's really not that simple to set up a scientific research project."

"Although I am no longer a rookie in the past, I still have suggestions with the leaders above, and I can get a lot of research funds."

"But technology is always innovating. If you don't do it at the beginning, someone who is more willing to do it will be the first to complete it."

"So people have already done these subjects now, and they have also upgraded the detection plan and widely promoted the new technology."

"The detection scheme we are using now is based on other people's results."

"Liu Fayi, don't be discouraged." Seeing Liu Fayi feeling a little emotional, Lu Weiwei hurried over to comfort her:

"Even if the diatom detection project is the first to produce results, we can still make breakthroughs in other fields."

"Hehe." Seeing Lu Weiwei's innocence, forensic assistant Gao Chuanfeng couldn't help laughing dryly, and said in a teasing way:

"I said, Lu Weiwei, do you think it's so easy to set up a scientific research project? Let me tell you, these so-called elite colleagues have not been idle all these years."

"Any scientific research projects that are easy to operate and easy to produce results have basically been done by others. At this stage, it is even more difficult to find scientific research projects in emerging fields."

"There are not a few decent high-standard laboratories as the foundation, why don't you go and show me?"

Lu Weiwei was stunned, and said weakly: "Okay, okay, I'll just talk casually. I'm really not good at scientific research, but Junior Brother Gu can help."

When Gu Chen heard this, he also nodded silently: "That's right, if there is anything that I, Gu Chen, can use, as long as it doesn't affect my work, I'm still willing to help. After all, I also need to learn."

"Haha." Listening to Gu Chen saying that he also wants to study, Forensic Doctor Liu laughed on the spot and said, "It's only you, Gu Chen, who has this enthusiasm, and it's not in vain for our Municipal Bureau's technical department to give you priority for testing every time. .”

Looking at the electron microscope in front of him, Forensic Liu also said with emotion: "There are new technologies, but at the beginning, the cost of the required equipment was too high, such as microwaves and scanning electron microscopes. Not every public security unit, especially It is what the grassroots units can afford.”

"So, why are the colleagues in Yangcheng so good? Because they also helped us think of it."

"For this reason, they have also specially considered a popularization plan with high quality and low price."

"You mean... Lefort's aqua regia?" Gu Chen asked.

Liu Fayi nodded fiercely: "Yes, it's Lefort Wang Shui. I didn't expect you, Gu Chen, to know this?"

"I understand a little bit, but I only understand the surface." Gu Chen actually knows a lot about this technology, and even made special reading notes in some scientific research magazines.

But Gu Chen would not act too lofty, but humbly expressed that he knew a little bit, and handed over the right to interpret Lefort's regia to Liu Fayi.

Liu Fayi also nodded along with the trend, and said involuntarily: "Because of the high cost of microwave digestion equipment, Lefort Regia was invented, which is a mixture of three parts nitric acid and one part hydrochloric acid digestion method."

"The effect is better than that of traditional strong acid digestion. It has the characteristics of simplicity, high efficiency, accurate qualitative and quantitative analysis, low cost, simple operation, and strong practicability."

Looking at the electron microscope in front of him, Forensic Liu smiled again: "The cost of the electron microscope is also very high, so our colleagues in Yangcheng tried to find a way to make the filter membrane transparent so that it can be observed through an optical microscope." .”

"And in order to fill the research gap on diatoms, they also collected water samples from all over the country, observed and classified the diatom components in them, and systematized the research on diatoms in China."

"As far as this is concerned, they are really hardworking. It is only natural that they can get such a great honor, and we don't need to be jealous."

"That's right, you get what you sow." Lu Weiwei said casually, feeling that this kind of scientific research is too cumbersome, and it's not something that ordinary scientific research teams can do.

Forensic doctor Liu said with a smile: "The multi-connected vacuum diatom enrichment equipment and consumables developed by the Yangcheng Criminal Bureau have achieved industrial transformation, and have been listed by the Ministry of Public Security as must-have equipment for provincial public security agencies."

"Currently, the criminal justice institute in Yangcheng has held many training courses, which has also attracted colleagues from all over the country to participate in the study, and has assisted many provinces and cities to establish diatom testing laboratories."

"Not only that, but also tested a series of difficult cases for the whole country, and all obtained clear conclusions, which played a key role in the characterization, disposal and litigation of the case."

"And the most important thing about them is... whether it is to assist in the inspection or to come to study, they will not charge a cent."

"No money?" Hearing this, Police Officer Wang was also shocked: "So... this is the pattern."

"That's right." Liu Forensic Medicine also smiled and said, "It's the happiest thing for people to solve problems for everyone."

"Furthermore, after the development of this technology, there have been a dozen to a few cases of complaints about dead bodies in water in Guangdong Province in the past, and there have been no complaints in the past three years. This is also the social benefit of the new method of forensic diatom detection."

"Recently, they are going to open another training class in Yangcheng to help train inspectors from all over the country to master the latest diatom detection technology."

"I'm also planning to pick a team to participate in. I don't know... are you interested?"

……

(End of this chapter)