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Dose reconstruction with Compton camera during proton therapy via subset-driven origin ensemble and double evolutionary algorithm

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Nuclear Science and Techniques 2023年第4期34卷 135-148页

作者： Zhi-Yang Yao yong-shun xiao Ji-Zhong Zhao Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle&Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China

Compton camera-based prompt gamma(PG) imaging has been proposed for range verification during proton therapy. However, a deviation between the PG and dose distributions, as well as the difference between the reconstructed PG and exact values, limit the effectiveness of the approach in accurate range monitoring during clinical applications. The aim of the study was to realize a PG-based dose reconstruction with a Compton camera, thereby further improving the prediction accuracy of in vivo range verification and providing a novel method for beam monitoring during proton therapy. In this paper, we present an approach based on a subset-driven origin ensemble with resolution recovery and a double evolutionary algorithm to reconstruct the dose depth profile(DDP) from the gamma events obtained by a cadmium-zinc-telluride Compton camera with limited position and energy resolution. Simulations of proton pencil beams with clinical particle rate irradiating phantoms made of different materials and the CT-based thoracic phantom were used to evaluate the feasibility of the proposed method. The results show that for the monoenergetic proton pencil beam irradiating homogeneous-material box phantom,the accuracy of the reconstructed DDP was within 0.3 mm for range prediction and within 5.2% for dose prediction. In particular, for 1.6-Gy irradiation in the therapy simulation of thoracic tumors, the range deviation of the reconstructed spreadout Bragg peak was within 0.8 mm, and the relative dose deviation in the peak area was less than 7% compared to the exact values. The results demonstrate the potential and feasibility of the proposed method in future Compton-based accurate dose reconstruction and range verification during proton therapy.

关键词： Prompt gamma imaging Dose reconstruction Range verification Origin ensemble Compton camera Evolutionary algorithm

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Development and preliminary results of a large-pixel two-layer LaBr_(3) Compton camera prototype

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Nuclear Science and Techniques 2023年第8期34卷 100-114页

作者： Ming-Hao Dong Zhi-Yang Yao yong-shun xiao Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China

Lanthanum bromide(LaBr_(3))crystal has a high energy resolution and time resolution and has been used in Compton cameras(CCs)over the past few ***,LaBr_(3) crystal arrays are difficult to process because LaBr_(3) is easy to crack and break;thus,few LaBr_(3)-based CC prototypes have been *** this study,we designed and fabricated a large-pixel LaBr_(3) CC prototype and evaluated its performance with regard to position,energy,and angular *** used two 10×10 LaBr_(3) crystal arrays with a pixel size of 5 mm×5 mm,silicon photomultipliers(SiPMs),and corresponding decoding circuits to construct our ***,a framework based on a Voronoi diagram and a lookup table was developed for list-mode projection data *** Carlo(MC)simulations based on Geant4 and experiments were conducted to evaluate the performance of our CC *** lateral position resolution was 5 mm,and the maximum deviation in the depth direction was 2.5 and 5 mm for the scatterer and absorber,*** corresponding measured energy resolu-tions were 7.65%and 8.44%,respectively,at 511 *** experimental results of ^(137)Cs point-like sources were consistent with the MC simulation results with regard to the spatial positions and full widths at half maximum(FWHMs).The angular resolution of the fabricated prototype was approximately 6°when a point-like ^(137)Cs source was centrally placed at a distance of 5 cm from the *** proposed and investigated a large-pixel LaBr_(3) CC for the first time and verified its feasibility for use in accurate spatial positioning of radiative sources with a high angular *** proposed CC can satisfy the requirements of radiative source imaging and positioning in the nuclear industry and medical applications.

关键词： Compton camera Large pixel Gamma camera LaBr_(3)detector Prototype evaluation

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GPU-accelerated three-dimensional reconstruction method of the Compton camera and its application in radionuclide imaging

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Nuclear Science and Techniques 2023年第4期34卷 54-68页

作者： Ren-Yao Wu Chang-Ran Geng Feng Tian Zhi-Yang Yao Chun-Hui Gong Hao-Nan Han Jian-Feng Xu yong-shun xiao xiao-Bin Tang Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Engineering Physics Tsinghua UniversityBeijing 100084China School of Environmental and Biological Engineering Nanjing University of Science and TechnologyNanjing 210094China JYAMS PET Research and Development Limited Nanjing 211100China

A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method with scattering angle correction(CSS-BP-SC) can quickly perform the back-projection process of the Compton cone and can be used to precompute the list-mode maximum likelihood expectation maximization(LM-MLEM). A dedicated parallel architecture was designed for the graphics processing unit acceleration of the back-projection and iteration stage of the CSS-BP-SC-based LM-MLEM. The imaging results of the two-point source Monte Carlo(MC) simulation demonstrate that by analyzing the full width at half maximum along the three coordinate axes, the CSS-BP-SC-based LM-MLEM can obtain imaging results comparable to those of the traditional reconstruction algorithm, that is, the simple back-projection-based LM-MLEM. The imaging results of the mouse phantom MC simulation and experiment demonstrate that the reconstruction results obtained by the proposed method sufficiently coincide with the set radioactivity distribution, and the speed increased by more than 664 times compared to the traditional reconstruction algorithm in the mouse phantom experiment. The proposed method will further advance the imaging applications of Compton cameras.

关键词： Compton camera Three-dimensional reconstruction Radionuclide imaging GPU

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Graft-verse-host disease after liver transplantation:A report of two cases and review of literature

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World Journal of Gastroenterology 2008年第6期14卷 974-979页

作者： Zhi-yong Guo xiao-shun He Lin-Wei Wu xiao-Feng Zhu Wei-Qiang Ju Dong-Ping Wang Shen You Yi Ha Guo-Dong Wang Jie-Fu Huang Organ Transplantation center First Affiliated Hospital Sun Yat-Scn University Guangzhou 510080 Guangdong Province China

Graft-verse-host disease (GVHD) is an uncommon fatal complication following liver transplantation (LTx). In China's Mainland, only six cases have been reported with a morbidity rate up to 1%-2%. Definitive diagnosis was achieved by molecular techniques (HLA typing or PCR-STR) in only two cases and the remaining cases were diagnosed based on typical clinical features with exclusion of other possible causes. All patients died of septic shock or multiple organ failure even after administration of increased corticosteroids and supportive therapy, and reduced immunosuppressive agents. In our center, two cases of GVHD were found among 128 (1.56%) patients. One case was diagnosed by detecting lymphocyte macrochimerism through DNA-STR. Both of them died even after aggressive treatment. In China, the incidence of GVHD is similar to that reported by foreign centers except for an extremely bad prognosis. Rapid diagnosis is crucial for a better prognosis. In China, only 37.5% of cases are diagnosed by molecular methods. We recommend detecting lymphocyte macrochimerism through DNA-STR to get a rapid diagnosis, and interleukin 2-receptor antibody (basiliximab or daclizumab) therapy seems to be a good choice for the disease.

关键词： Graft-versus-host disease Liver transplantation Prognosis Diagnosis Treatment

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Correction to: Development and preliminary results of a large-pixel two-layer LaBr_(3) Compton camera prototype

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Nuclear Science and Techniques 2024年第1期35卷 34-34页

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电容器损耗因数的绝对测量

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计量学报 1988年第1期 14-19页

作者：金士杰阮永顺王晓超中国计量科学研究院

本文介绍用一组真空可变间隙电容器,在60Hz～10kHz频率范围内,绝对测定参考电容器损耗因数的结果。在测量过程中采用了完全替代法及微差法,以消除测量装置引入的误差;并用微处理机对测量数据用最小二乘法进行处理,以消除某些由于人的因... 详细信息

本文介绍用一组真空可变间隙电容器,在60Hz～10kHz频率范围内,绝对测定参考电容器损耗因数的结果。在测量过程中采用了完全替代法及微差法,以消除测量装置引入的误差;并用微处理机对测量数据用最小二乘法进行处理,以消除某些由于人的因素产生的误差。测量结果用环形交叉电容器进行了核对,在1kHz时,测定10、100pF电容器损耗因数的绝对不确定度（2σ）分别为1.5×10-7和1×10-7。

关键词：电容器环形交叉标称值不确定度电器转盘式交叉平面交叉额定值损耗因数可变间隙基本天体测量绝对测量

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Role of nutrition in diabetes mellitus and infections

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World Journal of Clinical Cases 2025年第3期13卷 1-8页

作者： Xue-Lu Yu Li-Yun Zhou xiao Huang Xin-Yue Li Ming-Ke Wang Ji-shun Yang Naval Medical Center of PLA Naval Medical UniversityShanghai 200052China

In this editorial,we have commented on the article that has been published in the recent issue of World Journal of Clinical *** authors have described a case of unilateral thyroid cyst and have opined that the acute onset of infection may be linked to diabetes mellitus(DM).We have focused on the role of nutrition in the association between DM and *** with DM are at a high risk of infection,which could also be attributed to nutrition-related *** interventions for patients with diabetes are mainly based on a low-calorie diet,which can be achieved by adhering to a low-carbohydrate ***,dietary fiber supplementation is recommended to maintain the diversity of the gut ***,high-quality protein can prevent the increased risk of infection due to *** of vitamins C,vitamins A,vitamins D,and folic acid improves blood sugar control and facilitates immune *** deficiencies augment the risk of infection,but the relationship with diabetes is mostly U-shaped and a good intake should be maintained.

关键词： Diabetes mellitus Infection Macronutrients Vitamins Minerals

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锗锡浓度对硅锗锡合金性能影响的研究

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原子与分子物理学报 2025年第5期42卷 163-174页

作者：顾永顺温淑敏内蒙古工业大学理学院呼和浩特010051

由于SiGeSn合金材料其具有高的载流子迁移率和较长的载流子寿命,并且其结构具有较高的热力学稳定性,所以在光电子领域中是一种具有非常大应用潜力的半导体材料.本文采用密度泛函理论中的广义梯度近似GGA+U的方法,构建并计算了本征半导体... 详细信息

由于SiGeSn合金材料其具有高的载流子迁移率和较长的载流子寿命,并且其结构具有较高的热力学稳定性,所以在光电子领域中是一种具有非常大应用潜力的半导体材料.本文采用密度泛函理论中的广义梯度近似GGA+U的方法,构建并计算了本征半导体Si_(96)与五组掺杂模型Si_(92)Ge_(2)Sn_(2)、Si_(88)Ge_(4)Sn_(4)、Si_(84)Ge_(6)Sn_(6)、Si_(80)Ge_(8)Sn_(8)、Si_(76)Ge_(10)Sn_(10)的电子结构及光学性质.通过对计算结果的分析可知,Ge,Sn的加入使得Si材料的带隙宽度减小,并且发生了由间接带隙向直接带隙的转变;Ge,Sn浓度最高的SiGeSn合金的形成能相对较高,稳定性相较于Ge,Sn含量低的材料较差;随着Ge,Sn掺杂浓度的提高,电子态密度图显示出越来越明显的杂化现象,并且态密度的峰值主要有Si原子的s轨道提供;Ge,Sn浓度的提高还使得SiGeSn合金的吸收系数在可见光及近红外区域内增加、反射率在可见光及以上波段范围内提高、折射率变低、消光系数曲线向红外区域移动等光学性质变化,表明可以通过调节Ge,Sn浓度来获得合适的光学特性,这为SiGeSn半导体在红外区域光电材料和器件的应用上提供了研究方向.

关键词： SiGeSn 电子特性光学性质

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Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge Duo Xu xiao Feng Xing Yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao yong Du Zhe Sun Weilin Xu Jian Fang College of Textile and Clothing Engineering Soochow UniversitySuzhou 215123People’s Republic of China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China Department of Electrical and Computer Engineering University of MassachusettsAmherstMA 01003USA Department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK College of Textile Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and Engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion

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康普顿抑制γ谱仪的模拟计算

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计算物理 1988年第2期 189-196页

作者：冯正永王韶舜肖臣国中国科学技术大学近代物理系中国科学技术大学近代物理系合肥

本文用蒙特卡罗方法模拟计算了康普顿抑制γ谱仪探测γ射线的物理过程,对187Cs 662 kcV γ射线和60Co 1173-1332 kcV级联γ射线的模拟计算结果与实际测量相符。本工作对于康普顿抑制γ谱仪的物理设计具有意义。

关键词：康普顿坪物理设计光子冯正连续谱抑制效果蒙特卡罗方法玻色子反符合探测器模拟计算全能峰谱仪死层厚度

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