Radiation protection programs aims to reduce the radiation dose to the lowest possible level under the Dose Limit (DL) limit by the national or international laws, while the dose monitoring programs working as scale u...Radiation protection programs aims to reduce the radiation dose to the lowest possible level under the Dose Limit (DL) limit by the national or international laws, while the dose monitoring programs working as scale used to evaluating the efficiency of these programs and tools. In this study, the average of the annual Eff dose for the intensive care units at Hamad General Hospital (HGH) is less than the 50% of DL. It was aiming also to evaluate the efficiency of the radiation safety requirements (especially the shielding Adequacy) for the non radiation workers at oncology centers, hence several monitors were installed in chosen locations outside the radiation treatment machine from 2007 to 2011.展开更多
Objective This study aimed to evaluate the association between occupational radiation exposure and changes in thyroid hormone levels among medical radiation workers.Methods This retrospective cohort study included 2,9...Objective This study aimed to evaluate the association between occupational radiation exposure and changes in thyroid hormone levels among medical radiation workers.Methods This retrospective cohort study included 2,946 radiation workers from 20 Guangzhou hospitals.Data on general characteristics,participant radiation dosimetry,and thyroid function test results[thyroid-stimulating hormone(TSH),triiodothyronine(T3),and thyroid hormone(T4)]were extracted from dosimetry and medical records.The generalized estimating equation was used to evaluate the trend of changes in thyroid hormone levels over time and was adjusted for age,gender,and occupation.Results The average annual effective dose was very low and showed a general downward trend.During the follow-up period,changes in T3 and T4 levels among radiation workers were-0.015[95% confidence interval(CI)-0.018 to-0.012]nmol/L per year and-2.294(95%CI-2.426 to-2.162)nmol/L per year,respectively.Thyroid hormone levels were significantly different between males and females.T3 levels in the group of upper quartile of dose were significantly higher than in the lower quartile group(P=0.006).No significant decreased trend in thyroid hormone levels was observed with increasing average effective doses.Conclusion Thyroid hormone secretion might be affected even in low-dose radiation exposure environments.展开更多
The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and...The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and calibration of radiation monitoring instruments in a secondary standard dosimetry laboratory. In Nigeria, the suboptimal performances of these instruments are attributed to inadequate maintenance practices, insufficient calibration, and limited awareness of proper equipment handling for optimal use. This study assesses the current practices related to the optimal use, maintenance, repair, and calibration of radiation detection equipment across Nigeria’s six geopolitical zones. Using a cross-sectional survey approach, data were collected from Ninety (90) radiation monitoring equipment operators, Radiation Safety Officers, and frontline responders to evaluate their knowledge, awareness, and practices concerning equipment usage, operation, storage, handling, and calibration. The findings reveal significant gaps in knowledge of usage (trained is 43.2%, not trained is 56.8%) and inconsistencies in maintenance practices (as indicated by the regression analysis (β = 0.51, p < 0.01), particularly regarding specialized instruments such as the PackEye, Mobile Detection System (MDS), Radionuclide Identifinder (RID), and Personal Radiation Detectors (PRD). While there is high awareness of the need for regular calibration and handling training, the lack of standardized protocols and training alignment poses challenges to the effective use of these instruments. This study underscores the importance of comprehensive training programs, standardized maintenance protocols, and enhanced awareness initiatives to optimize the usage, performance and safety of radiation monitoring instruments in Nigeria.展开更多
Terahertz(THz)radiation possesses unique properties that make it a promising light source for applications in various fields,particularly spectroscopy and imaging.Ongoing research and development in THz technology has...Terahertz(THz)radiation possesses unique properties that make it a promising light source for applications in various fields,particularly spectroscopy and imaging.Ongoing research and development in THz technology has focused on developing or improving THz sources,detectors,and applications.At the PBP-CMU Electron Linac Laboratory(PCELL)of the Plasma and Beam Physics Research Facility in Chiang Mai University,high-intensity THz radiation has been generated in the form of coherent transition radiation(TR)and investigated since 2006 for electron beams with energies ranging from 8 to 12 MeV.In this study,we investigate and optimize the coherent TR arising from short electron bunches with energies ranging from 8 to 22 MeV using an upgraded linear-accelerator system with a higher radio-frequency(RF)power system.This radiation is then transported from the accelerator hall to the experimental room,in which the spectrometers are located.Electron-beam simulations are conducted to achieve short bunch lengths and small transverse beam sizes at the TR station.Radiation properties,including the radiation spectrum,angular distribution,and radiation polarization,are thoroughly investigated.The electron-bunch length is evaluated using the measuring system.The radiation-transport line is designed to achieve optimal frequency response and high transmission efficiency.A radiation-transmission efficiency of approximately 80-90%can be achieved with this designed system,along with a pulse energy ranging from 0.17 to 0.25μJ.The expected radiation spectral range covers up to 2 THz with a peak power of 0.5-1.25 MW.This coherent,broadband,and intense THz radiation will serve as a light source for THz spectroscopy and THz time-domain spectroscopy applications at the PCELL in the near future.展开更多
Nanoscale metal-based tunneling junction(MTJ)devices were fabricated using the electromigration method,and their electrical properties were studied after exposure toγ-andβ-radiation.Irradiation caused the set thresh...Nanoscale metal-based tunneling junction(MTJ)devices were fabricated using the electromigration method,and their electrical properties were studied after exposure toγ-andβ-radiation.Irradiation caused the set threshold voltage(V_(set))of the MTJ devices to increase,leading to a transition from a low-resistance state(LRS)to a high-resistance state(HRS).This shift in V_(set)was due to atom displacement from high-energy electrons excited byγ-andβ-radiation.Unlike semiconductor devices,MTJ devices showed resilience to permanent damage and could be restored in-situ through multiple I-V(I is the drain current;V is the drain voltage)sweeps with appropriate configurations.This ability to recover suggests that MTJ devices have promising potential under irradiation.The reparability of irradiated MTJ devices is closely related to nothing-on-insulator(NOI)their structure,providing insights for other NOI and metal-based micro-nanoscale devices.展开更多
Outcomes in patients with gastric cancer in the United States remain disappointing, with a five-year overall survival rate of approximately 23%. Given high rates of local-regional control following surgery, a strong r...Outcomes in patients with gastric cancer in the United States remain disappointing, with a five-year overall survival rate of approximately 23%. Given high rates of local-regional control following surgery, a strong rationale exists for the use of adjuvant radiation therapy. Randomized trials have shown superior local control with adjuvant radiotherapy and improved overall survival with adjuvant chemoradiation. The benefit of adjuvant chemoradiation in patients who have undergone D2 lymph node dissection by an experienced surgeon is not known, and the benefit of adjuvant radiation therapy in addition to adjuvant chemotherapy continues to be defined. In unresectable disease, chemoradiation allows long-term survival in a small number of patients and provides effective palliation. Most trials show a benefit to combined modality therapy compared to chemotherapy or radiation therapy alone. The use of pre-operative, intra-operative, 3D conformal, and intensity modulated radiation therapy in gastric cancer is promising but requires further study. The current article reviews the role of radiation therapy in the treatment of resectable and unresectable gastric carcinoma, focusing on current recommendations in the United States.展开更多
Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper...Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.展开更多
Aggregation-induced emission(AIE)is a unique phenomenon where certain organic materials exhibit enhanced luminescence in their aggregated states,overcoming the typical quenching observed in conventional organic materi...Aggregation-induced emission(AIE)is a unique phenomenon where certain organic materials exhibit enhanced luminescence in their aggregated states,overcoming the typical quenching observed in conventional organic materials.Since its discovery in 2001,AIE has driven significant advances in fields like OLEDs and biological imaging,earning recognition in fundamental research.However,its application in high-energy radiation detection remains underexplored.Organic scintillators,though widely used,face challenges such as low light yield and poor radiation attenuation.AIE materials offer promising solutions by improving light yield,response speed,and radiation attenuation.This review summarizes the design strategies behind AIE scintillators and their very recent applications in X-ray,γ-ray,and fast neutron detection.We highlight their advantages in enhancing detection sensitivity,reducing background noise,and achieving high-resolution imaging.By addressing the current challenges,we believe AIE materials will play a pivotal role in advancing future radiation detection and imaging technologies.展开更多
In order to meet the growing global energy demand and fulfill energy conservation and emission reduction goals, the efficient utilization of solar energy is becoming increasingly critical. However, the effects of high...In order to meet the growing global energy demand and fulfill energy conservation and emission reduction goals, the efficient utilization of solar energy is becoming increasingly critical. However, the effects of high temperatures on solar absorption are rarely considered in practical research. Therefore, this study presents a porous zinc and silver sulfide solar absorber with high-temperature radiative cooling capabilities. The solar absorption rate and radiative cooling efficiency in the high-temperature range(636 K–1060 K) are computed using the finite-difference time-domain method. Furthermore, the impact of parameters such as characteristic length, porosity, incident angle, and pore shape factor on both the absorption rate and efficiency of the solar absorber is analyzed. The mechanism is further examined from the perspective of microscopic thermal radiation. The results show that, in the high-temperature range, the solar absorption rate increases with higher porosity and incident angles, reaching its peak when the characteristic length is 1 μm. These findings highlight the significant potential of the solar absorber for efficient solar energy harvesting in photo-thermal conversion applications within a specific high-temperature range.展开更多
Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effecti...Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effective drug has been approved in clinical.In a recent work pub-lished in MedComm,Gao and her team reported,for the first time,cannabidiol(CBD)as an outstanding radioprotection agent targeting acute radiation-induced hematopoietic injury^([2]).Within two weeks post radiation,CBD can pro-mote the stemness of hematopoietic stem cells to a regular level.Using single-cell RNA sequencing(scRNA-seq)and functional assay,the authors decoded molecular changes underlying radiation-induced damage and CBD-induced recovery in HSCs.展开更多
Prostate cancer is the most common non-cutaneous cancers occurring in American men,and whilemost men with early-stage prostate cancers are cured,up to a third might manifest with biochemical recurrence(BCR)of prostate...Prostate cancer is the most common non-cutaneous cancers occurring in American men,and whilemost men with early-stage prostate cancers are cured,up to a third might manifest with biochemical recurrence(BCR)of prostate cancer.BCR is a disease entitywhich is characterized by a rising prostate-specific antigen(PSA)in the setting of a previously treated localized prostate cancerwith either surgery or radiation therapywith curativeintent.展开更多
We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasm...We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasma parameters comprehensively measured through diverse diagnostic techniques.High-resolution observations show the implosion progressing through three stages:compression,expansion,and recompression.An anomalous demagnetization phenomenon is observed during the first compression stage,wherein the magnetic field at the plasma center is depleted as the density increases.We reveal the demagnetization mechanism and formulate a straightforward criterion for determining its occurrence,through analysis based on extended-magnetohydrodynamics theory and a generalized Ohm’s law.Additionally,we quantitatively evaluate the radiation losses and magnetic field variations during the two compression stages,providing experimental evidence that magnetic transport can influence the radiation properties by altering the plasma hydrodynamics.Furthermore,extrapolated results using our findings reveal direct relevance to magnetized inertial confinement fusion,space,and astrophysical plasma scenarios.展开更多
Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe...Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.展开更多
Background:Previous experiments have demonstrated that hypofractionated radiation therapy(HFRT),low-dose radiation therapy(LDRT),and combined anti-programmed cell death protein 1(αPD-1)can enhance the abscopal effect...Background:Previous experiments have demonstrated that hypofractionated radiation therapy(HFRT),low-dose radiation therapy(LDRT),and combined anti-programmed cell death protein 1(αPD-1)can enhance the abscopal effect.Combined with the phenomenon of low prognosis in patients with breast cancer lung metastasis,our study establishes a mouse model and changes the irradiation regimen of LDRT to explore its preventive effect on breast cancer lung metastasis.Methods:The breast cancer subcutaneous graft tumor model was developed.Two-lung prophylactic LDRT was performed prior to the onset of lung metastases,in combination with HFRT(8 Gy,3f),andαPD-1(200μg,4f)therapy.We watched and documented the tumor volume,survival duration,and number of lung metastases.Furthermore,after labeling the corresponding cells using markers,we detected immune-related cell infiltration by immunohistochemistry and flow cytometry,such as T cells.We also determined the expression of cytokines(IFN-γand TNF-α)by enzyme-linked immunosorbent assay.Result:The triple therapy(HFRT+LDRT+αPD-1)resulted in tumor shrinkage and prolonged survival in mice,with median survival extending from 35 to 52 days.The most notable decrease in the quantity of advanced lung metastatic nodules in breast cancer was observed with the triple therapy(HFRT+LDRT+αPD-1)(p<0.05).Furthermore,according to immunohistochemistry and flow cytometry,the triple treatment(HFRT+LDRT+αPD-1)showed the greatest expression of CD8^(+)T cells.Additionally,the ratio of CD8^(+)/CD4^(+)T cells was considerably greater than that of the groups(p<0.0001).Triple therapy(HFRT+LDRT+αPD-1)increased the recruitment of DCs cells,promoted IFN-γand TNF-αexpression,and curbed the aggregation of MDSCs cells(p<0.05).Conclusion:Prophylactic LDRT to the lungs,based on HFRT andαPD-1,can enhance anti-tumor efficacy and prevent advanced lung metastases from breast cancer.The process involves boosting the recruitment of DCs and CD8^(+)T cells,preventing MDSC cell aggregation,and lessening the tumor microenvironment’s immunosuppressive effects.展开更多
Radiotherapy(RT)is the backbone of multimodality treatment of more than half of cancer cases.Despite new modern RT techniques,late complications may occur such as radiation proctitis(RP).The natural history of RP is u...Radiotherapy(RT)is the backbone of multimodality treatment of more than half of cancer cases.Despite new modern RT techniques,late complications may occur such as radiation proctitis(RP).The natural history of RP is unpredictable.Minor symptoms may resolve spontaneously or require conservative treatment.On the other hand,for similar and uncomplicated clinical contexts,symptoms may persist and can even be refractory to the progressive increase in treatment measures.Over the last decades,an enormous therapeutic armamentarium has been considered in RP,including hyperbaric oxygen therapy(HBOT).Currently,the evidence regarding the impact of HBOT on RP and its benefits is conflicting.Additional prospective and randomised studies are necessary to validate HBOT’s effectiveness in the‘real world’clinical practice.This article reviewed the relevant literature on pathophysiology,clinical presentation,different classifications and discuss RP management including a proposal for a therapeutic algorithm with a focus on HBOT.展开更多
Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex ...Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex laser-matter interaction,melt flow,and defect formation during LAM due to extremely large temperature gradient,fast cooling rate,and small time(millisecond)and space(micron)scales.The emergence of synchrotron radiation provides a feasible approach for in situ observation of the LAM process.This paper outlines the current development in real-time characterization of LAM by synchrotron radiation,including laser-matter interaction,molten pool evolution,solidification structure evolution,and defects formation and elimination.Furthermore,the future development direction and application-oriented research are also discussed.展开更多
Background:People working outdoors in the Map Ta Phut pollution control area of Thailand require comprehen-sive health monitoring.In the past,studies have been done on the health effects of pollutants.However,there ar...Background:People working outdoors in the Map Ta Phut pollution control area of Thailand require comprehen-sive health monitoring.In the past,studies have been done on the health effects of pollutants.However,there are few studies on musculoskeletal disorders(MSDs),and Thailand is struggling to meet the Sustainable Development Goals.Methods:This cross-sectional study examines access to health services and factors affecting MSDs among outdoor pollution workers(OPWs).The sample group includes OPWs,including local fisherman,street vendors,public car drivers,and traffic police.We studied 50 people from each of these groups,for a total of 200 people.Data were analyzed with inferential statistics using Chi-square test,McNemar test,and Univariate logistic regression.Results:The OPWs reported experiencing significantly more total MSDs pain than they did in the past(P<0.05).Factors affecting current MSDs pain,including occupation and working days per week,were significant(P<0.05).The street vendor group and public car driver group had(odds ratio[OR]=2.253,95%confidence interval[CI]:1.101 to 5.019)and(OR=2.681,95%CI:1.191 to 6.032)times higher risks of MSDs pain,respectively.OPWs who work>5 days per week had a(OR=1.464,95%CI:1.093 to 2.704)times higher risk of MSDs pain.52.7%of OPWs with MSDs,pain(n=110)had received an annual health check-up.In the past year,50.9%had minor illnesses and 21.8%had severe illnesses.OPWs receiving free treatment and visiting health service stations for no cost comprised 77.3%and 51.8%,respectively.60.9%used their right to receive treatment with universal health insurance cards.Conclusions:The study indicates that occupational groups with MSDs pain problems should exercise this right,according to the worker protection law.Local health agencies should organize activities or create accessible media to promote preventive medicine services,as many OPWs believe that health services can only be accessed when illness occurs.展开更多
The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium rad...The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.展开更多
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ...A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.展开更多
Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and pote...Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.展开更多
文摘Radiation protection programs aims to reduce the radiation dose to the lowest possible level under the Dose Limit (DL) limit by the national or international laws, while the dose monitoring programs working as scale used to evaluating the efficiency of these programs and tools. In this study, the average of the annual Eff dose for the intensive care units at Hamad General Hospital (HGH) is less than the 50% of DL. It was aiming also to evaluate the efficiency of the radiation safety requirements (especially the shielding Adequacy) for the non radiation workers at oncology centers, hence several monitors were installed in chosen locations outside the radiation treatment machine from 2007 to 2011.
基金supported by grants from the National Natural Science Foundation of China[81860604]Guangdong Science and Technology Program[2016A020215162]Innovating Strong School Project of Guangdong Pharmaceutical University[51359046]。
文摘Objective This study aimed to evaluate the association between occupational radiation exposure and changes in thyroid hormone levels among medical radiation workers.Methods This retrospective cohort study included 2,946 radiation workers from 20 Guangzhou hospitals.Data on general characteristics,participant radiation dosimetry,and thyroid function test results[thyroid-stimulating hormone(TSH),triiodothyronine(T3),and thyroid hormone(T4)]were extracted from dosimetry and medical records.The generalized estimating equation was used to evaluate the trend of changes in thyroid hormone levels over time and was adjusted for age,gender,and occupation.Results The average annual effective dose was very low and showed a general downward trend.During the follow-up period,changes in T3 and T4 levels among radiation workers were-0.015[95% confidence interval(CI)-0.018 to-0.012]nmol/L per year and-2.294(95%CI-2.426 to-2.162)nmol/L per year,respectively.Thyroid hormone levels were significantly different between males and females.T3 levels in the group of upper quartile of dose were significantly higher than in the lower quartile group(P=0.006).No significant decreased trend in thyroid hormone levels was observed with increasing average effective doses.Conclusion Thyroid hormone secretion might be affected even in low-dose radiation exposure environments.
文摘The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and calibration of radiation monitoring instruments in a secondary standard dosimetry laboratory. In Nigeria, the suboptimal performances of these instruments are attributed to inadequate maintenance practices, insufficient calibration, and limited awareness of proper equipment handling for optimal use. This study assesses the current practices related to the optimal use, maintenance, repair, and calibration of radiation detection equipment across Nigeria’s six geopolitical zones. Using a cross-sectional survey approach, data were collected from Ninety (90) radiation monitoring equipment operators, Radiation Safety Officers, and frontline responders to evaluate their knowledge, awareness, and practices concerning equipment usage, operation, storage, handling, and calibration. The findings reveal significant gaps in knowledge of usage (trained is 43.2%, not trained is 56.8%) and inconsistencies in maintenance practices (as indicated by the regression analysis (β = 0.51, p < 0.01), particularly regarding specialized instruments such as the PackEye, Mobile Detection System (MDS), Radionuclide Identifinder (RID), and Personal Radiation Detectors (PRD). While there is high awareness of the need for regular calibration and handling training, the lack of standardized protocols and training alignment poses challenges to the effective use of these instruments. This study underscores the importance of comprehensive training programs, standardized maintenance protocols, and enhanced awareness initiatives to optimize the usage, performance and safety of radiation monitoring instruments in Nigeria.
基金supported by the National Research Council of Thailand(No.NRCT-5-RSA63004-16)Chiang Mai University.S.Pakluea acknowledges scholarship support from the Science Achievement Scholarship of Thailand(SAST).
文摘Terahertz(THz)radiation possesses unique properties that make it a promising light source for applications in various fields,particularly spectroscopy and imaging.Ongoing research and development in THz technology has focused on developing or improving THz sources,detectors,and applications.At the PBP-CMU Electron Linac Laboratory(PCELL)of the Plasma and Beam Physics Research Facility in Chiang Mai University,high-intensity THz radiation has been generated in the form of coherent transition radiation(TR)and investigated since 2006 for electron beams with energies ranging from 8 to 12 MeV.In this study,we investigate and optimize the coherent TR arising from short electron bunches with energies ranging from 8 to 22 MeV using an upgraded linear-accelerator system with a higher radio-frequency(RF)power system.This radiation is then transported from the accelerator hall to the experimental room,in which the spectrometers are located.Electron-beam simulations are conducted to achieve short bunch lengths and small transverse beam sizes at the TR station.Radiation properties,including the radiation spectrum,angular distribution,and radiation polarization,are thoroughly investigated.The electron-bunch length is evaluated using the measuring system.The radiation-transport line is designed to achieve optimal frequency response and high transmission efficiency.A radiation-transmission efficiency of approximately 80-90%can be achieved with this designed system,along with a pulse energy ranging from 0.17 to 0.25μJ.The expected radiation spectral range covers up to 2 THz with a peak power of 0.5-1.25 MW.This coherent,broadband,and intense THz radiation will serve as a light source for THz spectroscopy and THz time-domain spectroscopy applications at the PCELL in the near future.
基金supported by the National Natural Science Foundation of China(Nos.T2293703,T2293700)the Instrumental Analysis Fund of Peking University,China(No.KF-2305-07).
文摘Nanoscale metal-based tunneling junction(MTJ)devices were fabricated using the electromigration method,and their electrical properties were studied after exposure toγ-andβ-radiation.Irradiation caused the set threshold voltage(V_(set))of the MTJ devices to increase,leading to a transition from a low-resistance state(LRS)to a high-resistance state(HRS).This shift in V_(set)was due to atom displacement from high-energy electrons excited byγ-andβ-radiation.Unlike semiconductor devices,MTJ devices showed resilience to permanent damage and could be restored in-situ through multiple I-V(I is the drain current;V is the drain voltage)sweeps with appropriate configurations.This ability to recover suggests that MTJ devices have promising potential under irradiation.The reparability of irradiated MTJ devices is closely related to nothing-on-insulator(NOI)their structure,providing insights for other NOI and metal-based micro-nanoscale devices.
文摘Outcomes in patients with gastric cancer in the United States remain disappointing, with a five-year overall survival rate of approximately 23%. Given high rates of local-regional control following surgery, a strong rationale exists for the use of adjuvant radiation therapy. Randomized trials have shown superior local control with adjuvant radiotherapy and improved overall survival with adjuvant chemoradiation. The benefit of adjuvant chemoradiation in patients who have undergone D2 lymph node dissection by an experienced surgeon is not known, and the benefit of adjuvant radiation therapy in addition to adjuvant chemotherapy continues to be defined. In unresectable disease, chemoradiation allows long-term survival in a small number of patients and provides effective palliation. Most trials show a benefit to combined modality therapy compared to chemotherapy or radiation therapy alone. The use of pre-operative, intra-operative, 3D conformal, and intensity modulated radiation therapy in gastric cancer is promising but requires further study. The current article reviews the role of radiation therapy in the treatment of resectable and unresectable gastric carcinoma, focusing on current recommendations in the United States.
文摘Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.
基金financial support from National Natural Science Foundation of China(No.22175156)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.162301202692).
文摘Aggregation-induced emission(AIE)is a unique phenomenon where certain organic materials exhibit enhanced luminescence in their aggregated states,overcoming the typical quenching observed in conventional organic materials.Since its discovery in 2001,AIE has driven significant advances in fields like OLEDs and biological imaging,earning recognition in fundamental research.However,its application in high-energy radiation detection remains underexplored.Organic scintillators,though widely used,face challenges such as low light yield and poor radiation attenuation.AIE materials offer promising solutions by improving light yield,response speed,and radiation attenuation.This review summarizes the design strategies behind AIE scintillators and their very recent applications in X-ray,γ-ray,and fast neutron detection.We highlight their advantages in enhancing detection sensitivity,reducing background noise,and achieving high-resolution imaging.By addressing the current challenges,we believe AIE materials will play a pivotal role in advancing future radiation detection and imaging technologies.
基金Project supported by the National Natural Science Foundation of China (Grant No. 52406102)Shandong Provincial Natural Science Foundation (Grant No. ZR2023QE258)。
文摘In order to meet the growing global energy demand and fulfill energy conservation and emission reduction goals, the efficient utilization of solar energy is becoming increasingly critical. However, the effects of high temperatures on solar absorption are rarely considered in practical research. Therefore, this study presents a porous zinc and silver sulfide solar absorber with high-temperature radiative cooling capabilities. The solar absorption rate and radiative cooling efficiency in the high-temperature range(636 K–1060 K) are computed using the finite-difference time-domain method. Furthermore, the impact of parameters such as characteristic length, porosity, incident angle, and pore shape factor on both the absorption rate and efficiency of the solar absorber is analyzed. The mechanism is further examined from the perspective of microscopic thermal radiation. The results show that, in the high-temperature range, the solar absorption rate increases with higher porosity and incident angles, reaching its peak when the characteristic length is 1 μm. These findings highlight the significant potential of the solar absorber for efficient solar energy harvesting in photo-thermal conversion applications within a specific high-temperature range.
文摘Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effective drug has been approved in clinical.In a recent work pub-lished in MedComm,Gao and her team reported,for the first time,cannabidiol(CBD)as an outstanding radioprotection agent targeting acute radiation-induced hematopoietic injury^([2]).Within two weeks post radiation,CBD can pro-mote the stemness of hematopoietic stem cells to a regular level.Using single-cell RNA sequencing(scRNA-seq)and functional assay,the authors decoded molecular changes underlying radiation-induced damage and CBD-induced recovery in HSCs.
文摘Prostate cancer is the most common non-cutaneous cancers occurring in American men,and whilemost men with early-stage prostate cancers are cured,up to a third might manifest with biochemical recurrence(BCR)of prostate cancer.BCR is a disease entitywhich is characterized by a rising prostate-specific antigen(PSA)in the setting of a previously treated localized prostate cancerwith either surgery or radiation therapywith curativeintent.
基金the State Key Development Program for Basic Research of China(Grant No.2022YFA1602503)the National Natural Science Foundation of China(Grant Nos.12120101005 and 12205247)
文摘We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasma parameters comprehensively measured through diverse diagnostic techniques.High-resolution observations show the implosion progressing through three stages:compression,expansion,and recompression.An anomalous demagnetization phenomenon is observed during the first compression stage,wherein the magnetic field at the plasma center is depleted as the density increases.We reveal the demagnetization mechanism and formulate a straightforward criterion for determining its occurrence,through analysis based on extended-magnetohydrodynamics theory and a generalized Ohm’s law.Additionally,we quantitatively evaluate the radiation losses and magnetic field variations during the two compression stages,providing experimental evidence that magnetic transport can influence the radiation properties by altering the plasma hydrodynamics.Furthermore,extrapolated results using our findings reveal direct relevance to magnetized inertial confinement fusion,space,and astrophysical plasma scenarios.
基金supported by the Guangdong High Level Innovation Research Institute(Grant No.2021B0909050006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the National Natural Science Foundation of China(Grant No.12205008)support from the National Science Fund for Distinguished Young Scholars(Grant No.12225501)。
文摘Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.
基金supported by a grant from the Southwest Medical University’s Program for Creating Popular Science Works(No.00160580).
文摘Background:Previous experiments have demonstrated that hypofractionated radiation therapy(HFRT),low-dose radiation therapy(LDRT),and combined anti-programmed cell death protein 1(αPD-1)can enhance the abscopal effect.Combined with the phenomenon of low prognosis in patients with breast cancer lung metastasis,our study establishes a mouse model and changes the irradiation regimen of LDRT to explore its preventive effect on breast cancer lung metastasis.Methods:The breast cancer subcutaneous graft tumor model was developed.Two-lung prophylactic LDRT was performed prior to the onset of lung metastases,in combination with HFRT(8 Gy,3f),andαPD-1(200μg,4f)therapy.We watched and documented the tumor volume,survival duration,and number of lung metastases.Furthermore,after labeling the corresponding cells using markers,we detected immune-related cell infiltration by immunohistochemistry and flow cytometry,such as T cells.We also determined the expression of cytokines(IFN-γand TNF-α)by enzyme-linked immunosorbent assay.Result:The triple therapy(HFRT+LDRT+αPD-1)resulted in tumor shrinkage and prolonged survival in mice,with median survival extending from 35 to 52 days.The most notable decrease in the quantity of advanced lung metastatic nodules in breast cancer was observed with the triple therapy(HFRT+LDRT+αPD-1)(p<0.05).Furthermore,according to immunohistochemistry and flow cytometry,the triple treatment(HFRT+LDRT+αPD-1)showed the greatest expression of CD8^(+)T cells.Additionally,the ratio of CD8^(+)/CD4^(+)T cells was considerably greater than that of the groups(p<0.0001).Triple therapy(HFRT+LDRT+αPD-1)increased the recruitment of DCs cells,promoted IFN-γand TNF-αexpression,and curbed the aggregation of MDSCs cells(p<0.05).Conclusion:Prophylactic LDRT to the lungs,based on HFRT andαPD-1,can enhance anti-tumor efficacy and prevent advanced lung metastases from breast cancer.The process involves boosting the recruitment of DCs and CD8^(+)T cells,preventing MDSC cell aggregation,and lessening the tumor microenvironment’s immunosuppressive effects.
文摘Radiotherapy(RT)is the backbone of multimodality treatment of more than half of cancer cases.Despite new modern RT techniques,late complications may occur such as radiation proctitis(RP).The natural history of RP is unpredictable.Minor symptoms may resolve spontaneously or require conservative treatment.On the other hand,for similar and uncomplicated clinical contexts,symptoms may persist and can even be refractory to the progressive increase in treatment measures.Over the last decades,an enormous therapeutic armamentarium has been considered in RP,including hyperbaric oxygen therapy(HBOT).Currently,the evidence regarding the impact of HBOT on RP and its benefits is conflicting.Additional prospective and randomised studies are necessary to validate HBOT’s effectiveness in the‘real world’clinical practice.This article reviewed the relevant literature on pathophysiology,clinical presentation,different classifications and discuss RP management including a proposal for a therapeutic algorithm with a focus on HBOT.
基金supported by the National Natural Science Foundation of China-Distinguished Young Scholars(No.52325407)the National Natural Science Foundation of China-Key Program(No.52234010)the Open Research Fund of the State Key Laboratory of Rolling and Automation,Northeastern University(No.2022RALKFKT004).
文摘Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex laser-matter interaction,melt flow,and defect formation during LAM due to extremely large temperature gradient,fast cooling rate,and small time(millisecond)and space(micron)scales.The emergence of synchrotron radiation provides a feasible approach for in situ observation of the LAM process.This paper outlines the current development in real-time characterization of LAM by synchrotron radiation,including laser-matter interaction,molten pool evolution,solidification structure evolution,and defects formation and elimination.Furthermore,the future development direction and application-oriented research are also discussed.
基金grant Fundamental Fund of National Science Research and Innovation Fund(NSRF)via Burapha University of Thailand(Grant number 52/2024).
文摘Background:People working outdoors in the Map Ta Phut pollution control area of Thailand require comprehen-sive health monitoring.In the past,studies have been done on the health effects of pollutants.However,there are few studies on musculoskeletal disorders(MSDs),and Thailand is struggling to meet the Sustainable Development Goals.Methods:This cross-sectional study examines access to health services and factors affecting MSDs among outdoor pollution workers(OPWs).The sample group includes OPWs,including local fisherman,street vendors,public car drivers,and traffic police.We studied 50 people from each of these groups,for a total of 200 people.Data were analyzed with inferential statistics using Chi-square test,McNemar test,and Univariate logistic regression.Results:The OPWs reported experiencing significantly more total MSDs pain than they did in the past(P<0.05).Factors affecting current MSDs pain,including occupation and working days per week,were significant(P<0.05).The street vendor group and public car driver group had(odds ratio[OR]=2.253,95%confidence interval[CI]:1.101 to 5.019)and(OR=2.681,95%CI:1.191 to 6.032)times higher risks of MSDs pain,respectively.OPWs who work>5 days per week had a(OR=1.464,95%CI:1.093 to 2.704)times higher risk of MSDs pain.52.7%of OPWs with MSDs,pain(n=110)had received an annual health check-up.In the past year,50.9%had minor illnesses and 21.8%had severe illnesses.OPWs receiving free treatment and visiting health service stations for no cost comprised 77.3%and 51.8%,respectively.60.9%used their right to receive treatment with universal health insurance cards.Conclusions:The study indicates that occupational groups with MSDs pain problems should exercise this right,according to the worker protection law.Local health agencies should organize activities or create accessible media to promote preventive medicine services,as many OPWs believe that health services can only be accessed when illness occurs.
基金supported by the Key-Area Research and Development Program of Guangdong Province(Grant No.2021B0909060004)the National Natural Science Foundation of China(Grant Nos.12072355 and 92271117)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620202).
文摘The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.
基金supported by the National Natural Science Foundation of China(No.U2067212)the National Science Fund for Distinguished Young Scholars(No.21925603).
文摘A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
基金supported by the National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2018ZX09201018–028)the nuclear energy development projects of China during the 13thFive Year Plan periodthe key research and development project of the Sichuan Provincial Department of Science and Technology(No.18ZDYF1466)。
文摘Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.
