Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current...Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current （DC） resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and discussed, including the observation mode, multiple inversions, and real-time monitoring. It is shown that a priori information constrained inversion is desirable to reduce the non-uniqueness of inversion, with which the accuracy of detection can be significantly improved. The focused resistivity method is prospective for advanced detection;with this method, the flanking interference can be reduced and the detection dis-tance is increased subsequently. The time-lapse resistivity inversion method is suitable for the regions with continuous conductivity changes, and it can be used to monitor water inrush in those regions. Based on above-mentioned features of various methods in terms of benefits and limitations, we propose a three-dimensional （3D） induced polarization method characterized with multi-electrode array, and introduce it into tunnels and mines combining with real-time monitoring with time-lapse inversion and cross-hole resistivity method. At last, the prospective applications of DC resistivity method are discussed as follows： （1） available advanced detection technology and instrument in tunnel excavated by tunnel boring machine （TBM）, （2） high-resolution detection method in holes, （3） four-dimensional （4D） monitoring technology for water inrush sources, and （4） estimation of water volume in water-bearing structures.展开更多
Drug delivery to the brain is crucial in the treatment for central nervous system disorders.While significant progress has been made in recent years,there are still major challenges in achieving controllable drug deli...Drug delivery to the brain is crucial in the treatment for central nervous system disorders.While significant progress has been made in recent years,there are still major challenges in achieving controllable drug delivery to the brain.Unmet clinical needs arise from various factors,including controlled drug transport,handling large drug doses,methods for crossing biological barriers,the use of imaging guidance,and effective models for analyzing drug delivery.Recent advances in micro/nanosystems have shown promise in addressing some of these challenges.These include the utilization of microfluidic platforms to test and validate the drug delivery process in a controlled and biomimetic setting,the development of novel micro/nanocarriers for large drug loads across the blood-brain barrier,and the implementation of micro-intervention systems for delivering drugs through intraparenchymal or peripheral routes.In this article,we present a review of the latest developments in micro/nanosystems for controllable drug delivery to the brain.We also delve into the relevant diseases,biological barriers,and conventional methods.In addition,we discuss future prospects and the development of emerging robotic micro/nanosystems equipped with directed transportation,real-time image guidance,and closed-loop control.展开更多
基金supported by the National Program on Key Basic Research Project of China (973 Program) (Nos. 2013CB036002 and 2014CB046901)the National Key Technology R&D Program of the Ministry of Science and Technology of China (No. 2013BAK06B01)the National Natural Science Foundation of China (No. 51139004)
文摘Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current （DC） resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and discussed, including the observation mode, multiple inversions, and real-time monitoring. It is shown that a priori information constrained inversion is desirable to reduce the non-uniqueness of inversion, with which the accuracy of detection can be significantly improved. The focused resistivity method is prospective for advanced detection;with this method, the flanking interference can be reduced and the detection dis-tance is increased subsequently. The time-lapse resistivity inversion method is suitable for the regions with continuous conductivity changes, and it can be used to monitor water inrush in those regions. Based on above-mentioned features of various methods in terms of benefits and limitations, we propose a three-dimensional （3D） induced polarization method characterized with multi-electrode array, and introduce it into tunnels and mines combining with real-time monitoring with time-lapse inversion and cross-hole resistivity method. At last, the prospective applications of DC resistivity method are discussed as follows： （1） available advanced detection technology and instrument in tunnel excavated by tunnel boring machine （TBM）, （2） high-resolution detection method in holes, （3） four-dimensional （4D） monitoring technology for water inrush sources, and （4） estimation of water volume in water-bearing structures.
基金The work is supported by Shanghai Municipal Science and Technology Major Project(grant no.2021SHZDZX)the Science and Technology Commission of Shanghai Municipality(grant no.20DZ2220400)the Shanghai Pilot Program for Basic Research Shanghai Jiao Tong University(grant no.21TQ1400203).The authors acknowledge support from the Center for Hospital Automation and High Throughput Robotics,Institute of Medical Robotics,School of Biomedical Engineering,Shanghai Jiao Tong University.The authors acknowledge Ziyi Zhang for her help preparing the schematics.
文摘Drug delivery to the brain is crucial in the treatment for central nervous system disorders.While significant progress has been made in recent years,there are still major challenges in achieving controllable drug delivery to the brain.Unmet clinical needs arise from various factors,including controlled drug transport,handling large drug doses,methods for crossing biological barriers,the use of imaging guidance,and effective models for analyzing drug delivery.Recent advances in micro/nanosystems have shown promise in addressing some of these challenges.These include the utilization of microfluidic platforms to test and validate the drug delivery process in a controlled and biomimetic setting,the development of novel micro/nanocarriers for large drug loads across the blood-brain barrier,and the implementation of micro-intervention systems for delivering drugs through intraparenchymal or peripheral routes.In this article,we present a review of the latest developments in micro/nanosystems for controllable drug delivery to the brain.We also delve into the relevant diseases,biological barriers,and conventional methods.In addition,we discuss future prospects and the development of emerging robotic micro/nanosystems equipped with directed transportation,real-time image guidance,and closed-loop control.
