Team:UESTC-China/Human Practices
overview
In the process of many iGEM teams carrying out projects, it is often impossible to develop projects that can be applied to life given the cost and schedule.In order to avoid this situation, we draw on the waterfall model in software engineering as a development model, which is divided into feasibility analysis, requirements analysis, project design and project realization. Human practice in the process is an indispensable tool for us throughout our entire process.We also hope that more iGEM teams can use such models to develop projects.
Feasibility Analysis
overview
In the process of brainstorming, a teammate proposed the idea of degrading antibiotics. After everyone's discussion, we decided to degrade ciprofloxacin in sewage from the most difficult antibiotic ciprofloxacin. In order to determine whether the project is feasible, we organized and participated in the 5th Southwest China iGEM Exchange Conference to determine the technical feasibility and visited the 7th Water Supply Plant in Chengdu to determine the economic feasibility, understood whether the policy is feasible in the 4th Water Purification Plant, and discussed the feasibility of applying the background exchange ideas with professor Weizhao Chen of Shenzhen University Through this series of activities, we decided to change from antibiotics in degraded water to recycling bins designed for expired drugs that can be recycled and degraded.
Technical feasibility
In our brainstorming process we have proposed the idea of degrading ciprofloxacin. In order to determine the technical feasibility, we held the 5th Southwestern iGEM exchange meeting with UESTC-Software at the University of Electronic Science and Technology. We invited Ms. Zhang Nan, Ambassador of Asia, to explain human practices to us, and invited the Army Military Medical University (Third Military Medical University), Sichuan University, Sichuan Agricultural University, and Xi'an Jiaotong University to exchange ideas.
RESULT:
“In the process of our idea presentation, during the process of project demonstration, students from Sichuan University and Ms. Zhang Nan made suggestions: Pay great attention to safety issues, because if genetic escape occurs, it will cause great impact on the environment.
So according to their suggestions, we designed the Blu-ray suicide system and decided to use the semantic inclusion method to further control our E. coli.
”
Application feasibility
When we designed the programme, we communicated with the SZU-China team. After we briefly introduced this year's project, Mr. Chen Wei zhao, pointed out that our project should be more practical, and we need to think more about the application scenario. Although we have been working on antibiotics in water, we have not considered the specific application scenarios and have not gone out of the experiment. So we should seriously consider applying our project to the factory. In terms of human practice, although there are many things to do, we can dig deep into an idea, such as expired drug recycling is a good idea.
RESULT:
“Although we have always wanted to deal with antibiotics in sewage, we have not carefully considered the application scenario,
so we decided to go to relevant plants to understand the specific process.
”Economic feasibility
In order to determine whether our project has economic value, we went to visit the Chengdu Waterworks No. 7 Factory and learned about the tap water treatment process. Director Zeng of the No. 7 Waterworks Factory introduced to us that the process of treating water at the No. 7 Waterworks is still a traditional chemical deposition method. When we asked him if he had considered the more advanced water treatment technologies like biological methods, he explained to us that some water plants used that method, but he didn’t intend to use such a method. Because the water source used by each water plant is different, and he believed the water plant should choose the most suitable and economical treatment process, not the latest. At present, the main water source of Chengdu waterworks is the Li River. The water quality of it is very good, so there is no need to deal with antibiotic technology.
RESULT:
“We found that our ideas are not suitable for the tap water treatment process, and we cannot maximize the benefits for the manufacturers.
After careful consideration, we believe that the feasibility of treating antibiotics in tap water is very low due to the lack of will of manufacturers. We decided to abandon the antibiotics in the tap water treatment process and turn our eys to water treatment in the sewage plant.
”Policy feasibility
In order to explore the national policy for the management of antibiotics in sewage and learn the process used now, we went to the fourth water purification plant in Chengdu.
We learned that the dirt is first filtered through the pretreatment system and the membrane grid station. In the MP-MBR system, activated sludge is used, and microorganisms in the activated sludge are used for degradation, and the MP-MBR membrane system filters out pollutants larger than 0.1 μm and most bacteria. The UV is then sterilized again to prevent damage to the machine that actually runs the diaphragm.
Technical director Mr. Ren Chi listened to our project ideas and made suggestions to us: At present, there is no concentration limit for antibiotics such as ciprofloxacin in the national sewage standard. The sewage plant is difficult to handle by itself .The sewage is transported to the sewage through pipelines,so there may also be leakage on the way to the environment. Therefore ,it is better to trace the source and go directly to the possible source of pollution for degradation.
We learned that the dirt is first filtered through the pretreatment system and the membrane grid station. In the MP-MBR system, activated sludge is used, and microorganisms in the activated sludge are used for degradation, and the MP-MBR membrane system filters out pollutants larger than 0.1 μm and most bacteria. The UV is then sterilized again to prevent damage to the machine that actually runs the diaphragm.
Technical director Mr. Ren Chi listened to our project ideas and made suggestions to us: At present, there is no concentration limit for antibiotics such as ciprofloxacin in the national sewage standard. The sewage plant is difficult to handle by itself .The sewage is transported to the sewage through pipelines,so there may also be leakage on the way to the environment. Therefore ,it is better to trace the source and go directly to the possible source of pollution for degradation.
RESULT:
“From a technical point of view, Mr. Ren Chi does not approve of our treatment of antibiotics in sewage. He suggested that we find the source of the problem and go there to deal with it. Because the sewage flowing into urban water purification plants mainly came ftom residental live quarter and the policy of resorting and recycling rabbish is popular all over the country,
we thought it would be better to make an expired drug recycling bin to provide a new solution for expired drugs.
”
conclusion
Combining the above investigations and analysis, we think that it is not feasible to treat antibiotics in water in terms of economy, implementation, policy, etc. We think of an expired drug recycling bin that can recycle and degrade expired drugs as environmentally friendly substances.
Demand Analysis
Overview
Demand analysis has a major impact on the entire project development phase and is the basis for project development. In order to determine the user's needs, we distributed more than 200 questionnaires for analysis, and visited a number of chain pharmacies to determine the function and performance of the recycling bin.
User needs analysis
In order to determine whether people can need such a device, we have released a questionnaire on the status of expired drugs, and a total of 240 valid questionnaires were collected.
RESULT:
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78.33% of respondents confirmed or inclined to think that there were expired drugs in their homes. It can be seen that the phenomenon of expired drugs in the family is still very common.
”Moreover, according to our analysis, when there are elderly people in the family, the respondents have a higher probability of regularly sorting out family medicines, thus improving the understanding of the drug situation in the home during the finishing process. This allows us to decide to regard elderly people as the project audience and pay attention to families with elderly people, improve the living habits and knowledge level of the elderly, and verify the practicality. In order to be more helpful to the elderly, we have also carried out educational activities on the elderly.
System Requirements Analysis
Visit the pharmacy
In order to determine that our recycling bins whether require some special functions or not, we visited several pharmacies and exchanged our projects with the staff of the store manager, pharmacist, salesperson and other staff around the treatment of expired drugs. They questioned our bins, is it safe to use E. coli degradation chambers? Will it harm people's bodies? Where is this recycling bin placed? Is it possible to get rewards people to fall into the box?
In order to determine that our recycling bins whether require some special functions or not, we visited several pharmacies and exchanged our projects with the staff of the store manager, pharmacist, salesperson and other staff around the treatment of expired drugs. They questioned our bins, is it safe to use E. coli degradation chambers? Will it harm people's bodies? Where is this recycling bin placed? Is it possible to get rewards people to fall into the box?
RESULT:
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We need to be more cautious about security issues. In addition to suicide switches and semantic inclusion, we design UV lamp sterilization zones in the recycling bin. We need to use the mathematical modeling of the recycling bins to determine how our recycling bins are set up in the city. We also think about what can be used as rewards to encourage people to use our projects.
”Project design
Overview
In the process of project design, using modular design principles, it is divided into three modules: genetic engineering design, hardware process design, and mathematical modeling urban layout design. In this process, we exchange ideas with five teachers and constantly improve our project.
Genetic engineering design
After consulting the data, the optimum PH value of drug dissolution and drug degradation is not the same. Our instructor told us that we can be divided into two bacteria by our system, one for testing and one for degradation. The teacher asked us to understand Let's get sensational.
RESULT:
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In order to be able to adapt to the hardware, we have designed a group effect. When ciprofloxacin is detected, the detected bacteria can start degrading bacteria and degrade when detected.
”
Hardware process design
We planned to use microfluidic technology to encapsulate Escherichia coli with alginate solution, CaCl2 solution and water. The gel beads formed can allow certain enzymes produced by E. coli to be released to the outside world, while E. coli can not be produced. Microorganisms in the environment also do not enter the gel. And E. coli can live for several days. It doesn't matter if other chemicals in the outside world can go in, as long as you can isolate most of the damage. However, we still have doubts about hardware fabrication, microfluidic chip fabrication, embedding and cross-linking methods, gene influx release, and E. coli survival. Just as we thought about the harmful substances entering the microbeads, the risk of cell escape, and so on, it coincided with Professor Yin Huabing from the University of Glasgow's biomedical engineering program, and we asked her about these problems.
RESULT:
“1. In terms of light source made by hardware, Professor Yin believes that it is feasible to use laser, but the teacher recommends using a light source: X-Cite LED fluorescence microscope to excite the light source.
2. The design of microfluidic chips is the most important and the most difficult step. The design process is too specialized, and the microfluidic chips currently applied to cell encapsulation are less, and the technology is less mature. Even if the chip is designed, it may take dozens of adjustments to achieve the function, and the cost is too high.
However, due to funding constraints, we decided to use laser light sources after repeated consideration.
2. The design of microfluidic chips is the most important and the most difficult step. The design process is too specialized, and the microfluidic chips currently applied to cell encapsulation are less, and the technology is less mature. Even if the chip is designed, it may take dozens of adjustments to achieve the function, and the cost is too high.
Taking the comprehensive consideration into account , we decided to abandon the use of microfluidic technology.
”Recycling bin position design
In order to make the processing device in the project can be placed reasonably in the cell, we apply mathematical methods to solve this problem. Whether the device is properly placed in the cell depends on the structural characteristics of the cell, the population of the community, and throwing drugs. When residents can accept the longest distance to walk, etc., the lack of consideration of these factors will cause the irrational position of the device, so we have established a mathematical model to scientifically place the processing device.
For the layout design of the recycling bin, click here you can see the details
For the layout design of the recycling bin, click here you can see the details
Project realization
Acquisition card selection and circuit design
After we made the second-generation device, we used the data detected by it to analyze the resolution of the acquisition card together with the teacher, and finally selected the appropriate 24-bit data acquisition development board.
RESULT:
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The teacher also provided suggestions for the design of the device and the circuit design to solve the problem of centralized power supply for pumps, lasers, development boards and other equipment.
”Hardware device selection
We and professor Ke Chen learned about the type and working principle of the detector, analyzed the advantages and disadvantages of common photoresistor, avalanche diode and photomultiplier tube in terms of cost, function, size and difficulty of use, and discussed the self-made filter and amplifier circuit. Difficulty and time cost.
RESULT:
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Finally, the plan to purchase an avalanche detector with its own amplifier circuit was decided.
”3D printing
In order to complete our hardware, we and professor Xiangyu Mao learned the basic operation and precautions of 3D printing. With the help of Mr.Mao, we analyzed the advantages and disadvantages of fused deposition rapid prototyping (FDM) technology and photocuring technology. After taking these advantages and disadvantages into account,we finally decided to use ABS for photocuring 3D printing.
RESULT:
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Considering the accuracy and cost of 3D printing, we improved the optical path and detail design of the device, and used 3D printers in Mao’s laboratory to print 3D printing of the second generation device to verify the design flaws of device in actual use. It greatly helped us to further improve the device.
”Bacterial box design
RESULT:
“Dr. Hanger provided suggestions for the design of our cartridges.
According to our needs, he proposed that we should design the interior of the capsule into the shape of funnel and he also pointed out the design requirements for some important details of the shape. We applied his suggestions to the design of our third generation device.
”