Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of th...Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.展开更多
Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix an...Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.展开更多
Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) rec...Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) received the joint replacement with double-stemmed hinge silicone implant. There were 2 males and l0 females with a mean age of 61.4 (range, 56-75) years old. Of them, 9 cases (11 feet) were hallux valgus with osteoarthritis; 1 case (2 feet) was rheumatic arthritis; 2 cases (2 feet) were traumatic arthritis. The sub)ective and objective results were evaluated during follow-up. Results All of the patients were followed up regularly with an average of 24.7 months, ranging from 12 to 38 months. Ten patients were completely satisfied with the operation; I patient showed partial saris- faction, and 1 patient was not satisfied because of the first matatarsophalangeal joint pain due to severe hy- perosteogeny surrounding the cut bone surface 3 years after the operation. Osteolysis around the implant occurred in 2 cases without clinical symptoms, and no special treatment was given. Conclusion The joint replacement is a preferable method in alleviating pain and improving walking function with proper indication.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12375157,12027902,and 11905011)。
文摘Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.
基金support provided by the National Science Fund for Distinguished Young Scholars(52325703)Postdoctoral Innovation Talents Support Program(BX20220066)+1 种基金China Postdoctoral Science Foundation(2022M720709)State Key Laboratory of Power System Operation and Control(SKLD23KM06).
文摘Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.
文摘Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) received the joint replacement with double-stemmed hinge silicone implant. There were 2 males and l0 females with a mean age of 61.4 (range, 56-75) years old. Of them, 9 cases (11 feet) were hallux valgus with osteoarthritis; 1 case (2 feet) was rheumatic arthritis; 2 cases (2 feet) were traumatic arthritis. The sub)ective and objective results were evaluated during follow-up. Results All of the patients were followed up regularly with an average of 24.7 months, ranging from 12 to 38 months. Ten patients were completely satisfied with the operation; I patient showed partial saris- faction, and 1 patient was not satisfied because of the first matatarsophalangeal joint pain due to severe hy- perosteogeny surrounding the cut bone surface 3 years after the operation. Osteolysis around the implant occurred in 2 cases without clinical symptoms, and no special treatment was given. Conclusion The joint replacement is a preferable method in alleviating pain and improving walking function with proper indication.
基金financial support by the National Natural Science Foundation of China(No.52206180)the Fundamental Research Funds for the Central Universities,China(No.WK2320000050)。
