Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinica...Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.展开更多
Most current biotechnology industries are based on batch or fed-batch fermentation processes,which often show low productivity and high production costs compared to chemical processes.To increase the economic competit...Most current biotechnology industries are based on batch or fed-batch fermentation processes,which often show low productivity and high production costs compared to chemical processes.To increase the economic competitiveness of biological processes,continuous fermentation technologies are being developed that offer significant advantages in comparison with batch/fed-batch fermentation processes,including:(1)removal of potential substrates and product inhibition,(2)prolonging the microbial exponential growth phase and enhancing productivity,and(3)avoiding repeated fermentation preparation and lowering operation and installation costs.However,several key challenges should be addressed for the industrial application of continuous fermentation processes,including(1)contamination of the fermentation system,(2)degeneration of strains,and(3)relatively low product titer.In this study,we reviewed and discussed metabolic engineering and synthetic biology strategies to address these issues.展开更多
The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study...The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study this problem and identify the two-step mechanism of stress relaxation.At short time scale,relaxation is fast,dominated by stress biased thermal fluctuation with a fixed short-range length scale(activation volume).At long time scale,relaxation is slow due to the emergence of a cooperative long-range length scale determined by the stress fluctuation.The cooperative length scale is proportional to the reciprocal of stress and the amplitude of stress fluctuation is the product of stress and activation volume.Based on this two-step mechanism,we propose a new kinetics equation to capture the stress relaxation effectively,where the short time relaxation is described by an Eyring-like local activation and the long-time relaxation is captured by a cooperative excitation process resorting to an extension from the random first order transition theory.Our equation fits the experimental data well and can serve as a model to guide the related experiments of relaxation processes in crystalline solids.展开更多
基金Nanning Technology and Innovation Special Program(20204122)and Research Grant for 100 Talents of Guangxi Plan.
文摘Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2100900)the National Natural Science Foundation of China(Grant Nos.21938004,22078172,and 21878172)DongGuan Innovative Research Team Program(Grant No.201536000100033).
文摘Most current biotechnology industries are based on batch or fed-batch fermentation processes,which often show low productivity and high production costs compared to chemical processes.To increase the economic competitiveness of biological processes,continuous fermentation technologies are being developed that offer significant advantages in comparison with batch/fed-batch fermentation processes,including:(1)removal of potential substrates and product inhibition,(2)prolonging the microbial exponential growth phase and enhancing productivity,and(3)avoiding repeated fermentation preparation and lowering operation and installation costs.However,several key challenges should be addressed for the industrial application of continuous fermentation processes,including(1)contamination of the fermentation system,(2)degeneration of strains,and(3)relatively low product titer.In this study,we reviewed and discussed metabolic engineering and synthetic biology strategies to address these issues.
基金financially supported by the National Natural Science Foundation of China (Nos.21873054,21774131 and 21544007)the National Natural Science Foundation of China (Nos.U1862205 and 51673110)China Petroleum & Chemical Corporation for financial support。
文摘The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study this problem and identify the two-step mechanism of stress relaxation.At short time scale,relaxation is fast,dominated by stress biased thermal fluctuation with a fixed short-range length scale(activation volume).At long time scale,relaxation is slow due to the emergence of a cooperative long-range length scale determined by the stress fluctuation.The cooperative length scale is proportional to the reciprocal of stress and the amplitude of stress fluctuation is the product of stress and activation volume.Based on this two-step mechanism,we propose a new kinetics equation to capture the stress relaxation effectively,where the short time relaxation is described by an Eyring-like local activation and the long-time relaxation is captured by a cooperative excitation process resorting to an extension from the random first order transition theory.Our equation fits the experimental data well and can serve as a model to guide the related experiments of relaxation processes in crystalline solids.
