Objective： To investigate the effects of brachytherapy with computed tomography-guided percutaneous radioactive 1-125 seeds interstitial implantation （ISI） synchronized chemotherapy and Chinese medicine （CM） for ...Objective： To investigate the effects of brachytherapy with computed tomography-guided percutaneous radioactive 1-125 seeds interstitial implantation （ISI） synchronized chemotherapy and Chinese medicine （CM） for the treatment of advanced stage of non-small cell lung cancer （NSCLC）. Methods： Ninety patients diagnosed with NSCLC by biopsy were randomly assigned to three groups： the synchronized therapy group （A）, the chemotherapy plus CM-treated group （B）, and the chemotherapy-treated group （C）; a 2-month course of treatment was administered to them all. The effectiveness of treatment was evaluated based on tumor size, tumor markers （carcinoembryonic, squamous cell carcinoma-associated antigen, and cytokeratin 19 fragment）, clinical symptoms, and quality of life （QOL） in patients. Results： The total effective rates of Groups A to C were 83.33%, 46.67%, and 43.33%, respectively. The tumor markers were reduced obviously in Group A, showing significant difference compared with those in the other two groups. Additionally, QOL was elevated and cancer-related symptoms were alleviated more significant in Group A than those in Group C （all P〈0.05）. Conclusion： The synchronized therapy of 1-125 implantation with chemotherapy and CM was a safe therapeutic method and can be regarded as a new mode for treatment of advanced-stage NSCLC.展开更多
Maximum likelihood estimation(MLE)is an effective method for localizing radioactive sources in a given area.However,it requires an exhaustive search for parameter estimation,which is time-consuming.In this study,heuri...Maximum likelihood estimation(MLE)is an effective method for localizing radioactive sources in a given area.However,it requires an exhaustive search for parameter estimation,which is time-consuming.In this study,heuristic techniques were employed to search for radiation source parameters that provide the maximum likelihood by using a network of sensors.Hence,the time consumption of MLE would be effectively reduced.First,the radiation source was detected using the k-sigma method.Subsequently,the MLE was applied for parameter estimation using the readings and positions of the detectors that have detected the radiation source.A comparative study was performed in which the estimation accuracy and time consump-tion of the MLE were evaluated for traditional methods and heuristic techniques.The traditional MLE was performed via a grid search method using fixed and multiple resolutions.Additionally,four commonly used heuristic algorithms were applied:the firefly algorithm(FFA),particle swarm optimization(PSO),ant colony optimization(ACO),and artificial bee colony(ABC).The experiment was conducted using real data collected by the Low Scatter Irradiator facility at the Savannah River National Laboratory as part of the Intelligent Radiation Sensing System program.The comparative study showed that the estimation time was 3.27 s using fixed resolution MLE and 0.59 s using multi-resolution MLE.The time consumption for the heuristic-based MLE was 0.75,0.03,0.02,and 0.059 s for FFA,PSO,ACO,and ABC,respectively.The location estimation error was approximately 0.4 m using either the grid search-based MLE or the heuristic-based MLE.Hence,heuristic-based MLE can provide comparable estimation accuracy through a less time-consuming process than traditional MLE.展开更多
Particle tracking techniques such as magnetic particle tracking,radioactive particle tracking and positron emission particle tracking are widely used in academia and industry to image the dynamics of particulate and m...Particle tracking techniques such as magnetic particle tracking,radioactive particle tracking and positron emission particle tracking are widely used in academia and industry to image the dynamics of particulate and multiphase systems.These techniques can provide detailed data concerning a range of important,whole-field quantities based only on the time-averaged dynamics of a small number of tracer particles.However,in order for this data to be reliable,the duration over which these time-averages are taken must be suitably long.Further,the‘minimum averaging time’required to produce good statistics depends sensitively on the system in question and,at present,cannot be determined a priori in advance of an experiment.In this paper,we take a step toward resolving this issue,using discrete element method simulations of a simple vibrofluidised granular bed to develop a series of scaling laws relating said minimum averaging time to a variety of key system variables.The scaling laws developed may be used by future experimentalists to predict the required averaging time for each given system during an experimental campaign,thus improving both the efficiency with which particle tracking techniques may be applied,and the reliability of the data produced thereby.展开更多
文摘Objective： To investigate the effects of brachytherapy with computed tomography-guided percutaneous radioactive 1-125 seeds interstitial implantation （ISI） synchronized chemotherapy and Chinese medicine （CM） for the treatment of advanced stage of non-small cell lung cancer （NSCLC）. Methods： Ninety patients diagnosed with NSCLC by biopsy were randomly assigned to three groups： the synchronized therapy group （A）, the chemotherapy plus CM-treated group （B）, and the chemotherapy-treated group （C）; a 2-month course of treatment was administered to them all. The effectiveness of treatment was evaluated based on tumor size, tumor markers （carcinoembryonic, squamous cell carcinoma-associated antigen, and cytokeratin 19 fragment）, clinical symptoms, and quality of life （QOL） in patients. Results： The total effective rates of Groups A to C were 83.33%, 46.67%, and 43.33%, respectively. The tumor markers were reduced obviously in Group A, showing significant difference compared with those in the other two groups. Additionally, QOL was elevated and cancer-related symptoms were alleviated more significant in Group A than those in Group C （all P〈0.05）. Conclusion： The synchronized therapy of 1-125 implantation with chemotherapy and CM was a safe therapeutic method and can be regarded as a new mode for treatment of advanced-stage NSCLC.
文摘Maximum likelihood estimation(MLE)is an effective method for localizing radioactive sources in a given area.However,it requires an exhaustive search for parameter estimation,which is time-consuming.In this study,heuristic techniques were employed to search for radiation source parameters that provide the maximum likelihood by using a network of sensors.Hence,the time consumption of MLE would be effectively reduced.First,the radiation source was detected using the k-sigma method.Subsequently,the MLE was applied for parameter estimation using the readings and positions of the detectors that have detected the radiation source.A comparative study was performed in which the estimation accuracy and time consump-tion of the MLE were evaluated for traditional methods and heuristic techniques.The traditional MLE was performed via a grid search method using fixed and multiple resolutions.Additionally,four commonly used heuristic algorithms were applied:the firefly algorithm(FFA),particle swarm optimization(PSO),ant colony optimization(ACO),and artificial bee colony(ABC).The experiment was conducted using real data collected by the Low Scatter Irradiator facility at the Savannah River National Laboratory as part of the Intelligent Radiation Sensing System program.The comparative study showed that the estimation time was 3.27 s using fixed resolution MLE and 0.59 s using multi-resolution MLE.The time consumption for the heuristic-based MLE was 0.75,0.03,0.02,and 0.059 s for FFA,PSO,ACO,and ABC,respectively.The location estimation error was approximately 0.4 m using either the grid search-based MLE or the heuristic-based MLE.Hence,heuristic-based MLE can provide comparable estimation accuracy through a less time-consuming process than traditional MLE.
文摘Particle tracking techniques such as magnetic particle tracking,radioactive particle tracking and positron emission particle tracking are widely used in academia and industry to image the dynamics of particulate and multiphase systems.These techniques can provide detailed data concerning a range of important,whole-field quantities based only on the time-averaged dynamics of a small number of tracer particles.However,in order for this data to be reliable,the duration over which these time-averages are taken must be suitably long.Further,the‘minimum averaging time’required to produce good statistics depends sensitively on the system in question and,at present,cannot be determined a priori in advance of an experiment.In this paper,we take a step toward resolving this issue,using discrete element method simulations of a simple vibrofluidised granular bed to develop a series of scaling laws relating said minimum averaging time to a variety of key system variables.The scaling laws developed may be used by future experimentalists to predict the required averaging time for each given system during an experimental campaign,thus improving both the efficiency with which particle tracking techniques may be applied,and the reliability of the data produced thereby.
