Finding the optimal dose combination in two-agent dose-finding trials is challenging due to limited sample sizes and the extensive range of potential doses.Unlike traditional chemotherapy or radiotherapy,which primari...Finding the optimal dose combination in two-agent dose-finding trials is challenging due to limited sample sizes and the extensive range of potential doses.Unlike traditional chemotherapy or radiotherapy,which primarily focuses on identifying the maximum tolerated dose(MTD),therapies involving targeted and immune agents facilitate the identifica-tion of an optimal biological dose combination(OBDC)by simultaneously evaluating both toxicity and efficacy.Cur-rently,most approaches to determining the OBDC in the literature are model-based and require complex model fittings,making them cumbersome and challenging to implement.To address these challenges,we developed a novel model-as-sisted approach called uTPI-Comb.This approach refines the established utility-based toxicity probability interval design by integrating a strategically devised zone-based local and global candidate set searching strategy,which can effectively optimize the decision-making process for two-agent dose escalation or de-escalation in drug combination trials.Extensive simulation studies demonstrate that the uTPI-Comb design speeds up the dose-searching process and provides substantial improvements over existing model-based methods in determining the optimal biological dose combinations.展开更多
In order to maximize the lethality and reversibility of the non-lethal laser weapons(NLLW) at the same time and thus provide a theoretical basis for the R&D of laser weapons in the future,this paper accurately ana...In order to maximize the lethality and reversibility of the non-lethal laser weapons(NLLW) at the same time and thus provide a theoretical basis for the R&D of laser weapons in the future,this paper accurately analyzed the limiting biological dose of irreversible damage to human skin caused by the NLLW.Firstly,based on the burn theory in medicine and the actual tactical background,this paper redefines the evaluation criteria of the limiting laser dose of NLLW to the human body.Secondly,on the basis of anatomical knowledge,a 5-layer finite element model(FEM) of superficial skin is proposed,constructed and verified,which can accurately describe the limiting reversible damage.Based on the optimized Pennes bioheat transfer equation,the diffusion approximation theory,the modified Beer-Lambert law,the Arrhenius equation,and combined with dynamic thermophysical parameters,this paper highly restored the temperature distribution and accurately solved the necrotic tissue distribution inside the human skin irradiated by 1064 nm laser.Finally,it is concluded that the maximum human dose of the1064 nm NLLW is 8.93 J/cm^(2),8.29J/cm^(2),and 8.17 J/cm^(2) when the light spots are 5 mm,10 mm and15 mm,respectively,and the corresponding output power of the weapon is 46.74 W,173.72 W and384.77 W.Simultaneously,the temperature and damage distribution in the tissue at the time of ultimate damage are discussed from the axial and radial dimensions,respectively.The conclusions and analysis methods proposed in this paper are of great guiding significance for future research in military,medical and many other related fields.展开更多
Chemotherapy is one of the curative treatmentmodality for several types of tumors. However, thedosage of antitumor drugs was limited by cytotoxicityof drugs to normal tissues, especially for bone marrow(myelosuppressi...Chemotherapy is one of the curative treatmentmodality for several types of tumors. However, thedosage of antitumor drugs was limited by cytotoxicityof drugs to normal tissues, especially for bone marrow(myelosuppression). Drug resistantce gene (hMDRI,hDHFR etc.) is expressed in many normal tissues. Itsover-expression in tumor cells give rise to the tumorresistant to many drugs. But, if we transfer the drugresistance gene into the normal hematopoietic stemcell (HSC), the expression of the foreign gene展开更多
The content analysis of radioactive waste and radiation dose evaluation is considered as one of the important factors in the reactor facility design.This kind of buildings consists of the concrete for the most part an...The content analysis of radioactive waste and radiation dose evaluation is considered as one of the important factors in the reactor facility design.This kind of buildings consists of the concrete for the most part and uses it as the structure and shield of the building.Generally,the concrete has impurities such as cobalt,europium,nickel,and cesium with specific content depending on the production method or manufacturing company.Dominant radioactive nuclides generated from the fundamental components of concrete are considered that it is less contributed to the radiation dose because they are beta decay nuclides in general.Thus,impurities of irradiated concrete in the reactor facilities,are considered occasionally an important evaluation factor for induced activity.In this study,the influence on the activation of impurities in concrete was evaluated from the radiation dose and induced activity calculations.The calculation was evaluated at the bio-shield which is one of the areas with the highest neutron irradiation among the concrete structure in the reactor facility.The results show that radioactive nuclides with gamma decay were produced in these impurities.Moreover,the radiation dose of concrete with impurities was higher than concrete without impurities.The increased radiation dose was quantified through the content of impurities.展开更多
Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety...Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.展开更多
Assessment of the exposure dose for workers is crucial to protecting workers from the radiological risk.This preliminary study estimates the potential radiological exposure for a soil remediation worker at a nuclear d...Assessment of the exposure dose for workers is crucial to protecting workers from the radiological risk.This preliminary study estimates the potential radiological exposure for a soil remediation worker at a nuclear decommissioning site contaminated with Cs-137 in Korea,and then calculates the maximum workable soil concentration to comply with the occupational dose constraint of 20 mSv per year.The Korean characteristic data,detailed exposure scenarios for workers by the type of work,and relevant exposure pathways were used in the dose estimation.As a result,the most severe exposure-induced work type was identified as the excavator operation with an annual individual dose of 5.92×10^-5 mSv for a unit concentration of soil,from which the derived maximum workable soil concentration was 3.38×105 Bq/kg.Furthermore,dose contribution by each exposure pathway was found to be decreased in the following order:external radiation exposure,soil ingestion,dust inhalation,and skin contamination.The results of this study are expected to be used effectively to optimize radiation protection for workers and establish appropriate work procedures for future site remediation.展开更多
The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly ...The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly defined ratio of relative inhalation dose level (RIDL) to assess indoor air quality (IAQ). A user defined function based on CFD (computational fluid dynamics) was developed, which integrated human motion model with TVOCs emission model in a high sidewall air supply ventilation mode. Based on simulation results of 10 cases, it is shown that the spatial concentration distribution of TVOCs is affected by human motion. TVOCs diffusion characteristic of building material is the most effective way to impact the TVOCs inhalation dose. From the RIDL index, case A-2 has the most serious IAQ problem, while case D-1 is of the best IAQ.展开更多
目的采用单源光子CT较低管电压联合Care Dose 4D技术,评价主动脉成像图像质量和辐射剂量。方法 43例患者按照扫描管电压随机分为2组,即120 k V组(n=19)和100 k V组(n=24)。平扫采用固定管电压(100、120 k V),增强扫描采用自动管电压调...目的采用单源光子CT较低管电压联合Care Dose 4D技术,评价主动脉成像图像质量和辐射剂量。方法 43例患者按照扫描管电压随机分为2组,即120 k V组(n=19)和100 k V组(n=24)。平扫采用固定管电压(100、120 k V),增强扫描采用自动管电压调节技术(Care k V),参考管电压预设为100、120 k V,平扫和增强扫描均联合Care Dose 4D技术。比较不同扫描条件下2组患者主动脉图像质量、CT值和辐射剂量变化,包括平均容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED)。结果平扫,2组主动脉上中下段CT值差异无统计学意义(P>0.05),100 k V组辐射剂量(CTDIvol、DLP、ED)明显低于120 k V组。平扫和增强扫描,100 k V组有效剂量ED较120 k V组分别降低41.36%和67.80%。Care 100 k V组主动脉各段的CT值均高于120 k V组(P<0.05),两组主动脉成像图像质量评分差异无统计学意义(P>0.05)。结论联合Care Dose 4D技术,Care k V低管电压能够明显降低主动脉CT血管成像辐射剂量,而图像质量不受影响。展开更多
国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新...国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新需求。本文介绍了IAEA辐射安全标准委员会(RASSC)的主要工作,并讨论了RASSC近期关注的辐射安全问题:针对现存照射辨识和管理方面的挑战,RASSC正在新制定一项关于现存照射的综合性安全导则;虽然国际放射防护委员会(ICRP)已经更新了职业人员内照射剂量系数,RASSC不会立即修订与之相关的安全标准,同时会持续关注成员国经验反馈;随着新型放疗技术的应用,RASSC近期还关注放射性核素治疗中的辐射防护、放疗患者的第二原发癌的风险。展开更多
基金This work was supported by the Natural Science Foundation of Anhui Province(2022AH050703)the National Natural Science Foundation of China(11671375).
文摘Finding the optimal dose combination in two-agent dose-finding trials is challenging due to limited sample sizes and the extensive range of potential doses.Unlike traditional chemotherapy or radiotherapy,which primarily focuses on identifying the maximum tolerated dose(MTD),therapies involving targeted and immune agents facilitate the identifica-tion of an optimal biological dose combination(OBDC)by simultaneously evaluating both toxicity and efficacy.Cur-rently,most approaches to determining the OBDC in the literature are model-based and require complex model fittings,making them cumbersome and challenging to implement.To address these challenges,we developed a novel model-as-sisted approach called uTPI-Comb.This approach refines the established utility-based toxicity probability interval design by integrating a strategically devised zone-based local and global candidate set searching strategy,which can effectively optimize the decision-making process for two-agent dose escalation or de-escalation in drug combination trials.Extensive simulation studies demonstrate that the uTPI-Comb design speeds up the dose-searching process and provides substantial improvements over existing model-based methods in determining the optimal biological dose combinations.
文摘In order to maximize the lethality and reversibility of the non-lethal laser weapons(NLLW) at the same time and thus provide a theoretical basis for the R&D of laser weapons in the future,this paper accurately analyzed the limiting biological dose of irreversible damage to human skin caused by the NLLW.Firstly,based on the burn theory in medicine and the actual tactical background,this paper redefines the evaluation criteria of the limiting laser dose of NLLW to the human body.Secondly,on the basis of anatomical knowledge,a 5-layer finite element model(FEM) of superficial skin is proposed,constructed and verified,which can accurately describe the limiting reversible damage.Based on the optimized Pennes bioheat transfer equation,the diffusion approximation theory,the modified Beer-Lambert law,the Arrhenius equation,and combined with dynamic thermophysical parameters,this paper highly restored the temperature distribution and accurately solved the necrotic tissue distribution inside the human skin irradiated by 1064 nm laser.Finally,it is concluded that the maximum human dose of the1064 nm NLLW is 8.93 J/cm^(2),8.29J/cm^(2),and 8.17 J/cm^(2) when the light spots are 5 mm,10 mm and15 mm,respectively,and the corresponding output power of the weapon is 46.74 W,173.72 W and384.77 W.Simultaneously,the temperature and damage distribution in the tissue at the time of ultimate damage are discussed from the axial and radial dimensions,respectively.The conclusions and analysis methods proposed in this paper are of great guiding significance for future research in military,medical and many other related fields.
文摘Chemotherapy is one of the curative treatmentmodality for several types of tumors. However, thedosage of antitumor drugs was limited by cytotoxicityof drugs to normal tissues, especially for bone marrow(myelosuppression). Drug resistantce gene (hMDRI,hDHFR etc.) is expressed in many normal tissues. Itsover-expression in tumor cells give rise to the tumorresistant to many drugs. But, if we transfer the drugresistance gene into the normal hematopoietic stemcell (HSC), the expression of the foreign gene
基金This work was supported by the R&D program throughout the National Fusion Research Institute(NFRI)funded by the Ministry of Science of the Republic of Korea(Project No.:201800000002652),and Innovative Technology Center for Radiation Safety(ITRS).
文摘The content analysis of radioactive waste and radiation dose evaluation is considered as one of the important factors in the reactor facility design.This kind of buildings consists of the concrete for the most part and uses it as the structure and shield of the building.Generally,the concrete has impurities such as cobalt,europium,nickel,and cesium with specific content depending on the production method or manufacturing company.Dominant radioactive nuclides generated from the fundamental components of concrete are considered that it is less contributed to the radiation dose because they are beta decay nuclides in general.Thus,impurities of irradiated concrete in the reactor facilities,are considered occasionally an important evaluation factor for induced activity.In this study,the influence on the activation of impurities in concrete was evaluated from the radiation dose and induced activity calculations.The calculation was evaluated at the bio-shield which is one of the areas with the highest neutron irradiation among the concrete structure in the reactor facility.The results show that radioactive nuclides with gamma decay were produced in these impurities.Moreover,the radiation dose of concrete with impurities was higher than concrete without impurities.The increased radiation dose was quantified through the content of impurities.
基金National Natural Science Foundation of China(12205028)Natural Science Foundation of Sichuan Province(2022NSFSC1235)Young and Middle-aged Backbone Teacher Foundation of Chengdu University of Technology(10912-JXGG2022-08363)。
文摘Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.
基金This study was supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(No.NRF-2017-M2A8A4015252)it has been conducted as a part of the project of emergency preparedness for nuclear research facilities in Korea Atomic Energy Research Institute(KAERI).
文摘Assessment of the exposure dose for workers is crucial to protecting workers from the radiological risk.This preliminary study estimates the potential radiological exposure for a soil remediation worker at a nuclear decommissioning site contaminated with Cs-137 in Korea,and then calculates the maximum workable soil concentration to comply with the occupational dose constraint of 20 mSv per year.The Korean characteristic data,detailed exposure scenarios for workers by the type of work,and relevant exposure pathways were used in the dose estimation.As a result,the most severe exposure-induced work type was identified as the excavator operation with an annual individual dose of 5.92×10^-5 mSv for a unit concentration of soil,from which the derived maximum workable soil concentration was 3.38×105 Bq/kg.Furthermore,dose contribution by each exposure pathway was found to be decreased in the following order:external radiation exposure,soil ingestion,dust inhalation,and skin contamination.The results of this study are expected to be used effectively to optimize radiation protection for workers and establish appropriate work procedures for future site remediation.
基金Projects(2006BAJ02A08, 2006BAJ02A05) supported by the National Science and Technology Pillar Program Project during the 11th Five-Year Plan PeriodProject(2007-209) supported by the Excellent Youth Teacher of Ministry of Education of China
文摘The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly defined ratio of relative inhalation dose level (RIDL) to assess indoor air quality (IAQ). A user defined function based on CFD (computational fluid dynamics) was developed, which integrated human motion model with TVOCs emission model in a high sidewall air supply ventilation mode. Based on simulation results of 10 cases, it is shown that the spatial concentration distribution of TVOCs is affected by human motion. TVOCs diffusion characteristic of building material is the most effective way to impact the TVOCs inhalation dose. From the RIDL index, case A-2 has the most serious IAQ problem, while case D-1 is of the best IAQ.
文摘目的采用单源光子CT较低管电压联合Care Dose 4D技术,评价主动脉成像图像质量和辐射剂量。方法 43例患者按照扫描管电压随机分为2组,即120 k V组(n=19)和100 k V组(n=24)。平扫采用固定管电压(100、120 k V),增强扫描采用自动管电压调节技术(Care k V),参考管电压预设为100、120 k V,平扫和增强扫描均联合Care Dose 4D技术。比较不同扫描条件下2组患者主动脉图像质量、CT值和辐射剂量变化,包括平均容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED)。结果平扫,2组主动脉上中下段CT值差异无统计学意义(P>0.05),100 k V组辐射剂量(CTDIvol、DLP、ED)明显低于120 k V组。平扫和增强扫描,100 k V组有效剂量ED较120 k V组分别降低41.36%和67.80%。Care 100 k V组主动脉各段的CT值均高于120 k V组(P<0.05),两组主动脉成像图像质量评分差异无统计学意义(P>0.05)。结论联合Care Dose 4D技术,Care k V低管电压能够明显降低主动脉CT血管成像辐射剂量,而图像质量不受影响。
文摘国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新需求。本文介绍了IAEA辐射安全标准委员会(RASSC)的主要工作,并讨论了RASSC近期关注的辐射安全问题:针对现存照射辨识和管理方面的挑战,RASSC正在新制定一项关于现存照射的综合性安全导则;虽然国际放射防护委员会(ICRP)已经更新了职业人员内照射剂量系数,RASSC不会立即修订与之相关的安全标准,同时会持续关注成员国经验反馈;随着新型放疗技术的应用,RASSC近期还关注放射性核素治疗中的辐射防护、放疗患者的第二原发癌的风险。
