BACKGROUND Primary ciliary dyskinesia(PCD)is a rare condition characterised by dysmotile,immotile,or absent cilia.As a result of the impairment in respiratory mucociliary clearance,patients with PCD typically develop ...BACKGROUND Primary ciliary dyskinesia(PCD)is a rare condition characterised by dysmotile,immotile,or absent cilia.As a result of the impairment in respiratory mucociliary clearance,patients with PCD typically develop neonatal respiratory distress,nasal congestion,otitis media and recurrent respiratory infections leading to bronchiectasis and structural lung changes.These changes have been shown by chest computed tomography(CT)to develop in infancy and early childhood.Recent development and refinement of radiation-reducing CT techniques have allowed significant radiation dose reductions,with chest CT doses now in the range of chest radiography(CR).AIM To evaluate the efficacy of ultra-low dose CT(ULDCT)chest in identifying pulmonary changes within a PCD paediatric patient cohort.METHODS Paediatric patients with PCD who presented for routine clinical outpatient follow-up within the study period,were eligible for inclusion in the study.ULDCT and CR were performed on these patients and the results compared.Comparison metrics included radiation dose,subjective and objective image quality and disease severity.RESULTS Six paediatric patients(mean age 9 years)underwent clinically indicated ULDCT chest examinations and CR for surveillance of their PCD.The mean effective dose was 0.08±0.02 mSv,a dose that approximates that of a frontal and lateral chest radiograph.The average Brody II score across the entire cohort was 12.92,with excellent interrater reliability and intra-class correlation coefficient(ICC)of 0.98.The average Chrispin-Norman score on CR was 1 with excellent inter-rater reliability and ICC of 0.92.CONCLUSION ULDCT demonstrates superior diagnostic capabilities,minimal radiation dose penalty,and high interobserver reliability in comparison to CR.Thus,we advocate for ULDCT to be the preferred modality for surveillance imaging in paediatric PCD.展开更多
Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice ...Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice were divided into five groups:Sham,CONV-RT10Gy,CONV-RT20Gy,FLASH-RT10Gy,and FLASH-RT20Gy.Three days post-irradiation,morphological changes in neurons within the dentate gyrus(DG),CA1,and CA3 were observed using hematoxylin and eosin and Nissl staining.The malondialdehyde(MDA),reduced glutathione(GSH),glutathione peroxidase(GSH-PX),superoxide dismutase(SOD),catalase(CAT),and hydroxyl radical(OH^(-))levels were measured using assay kits.Quantitative reverse transcription PCR was used to assess interleukin(IL)-1β,IL-6,inducible nitric oxide synthase(iNOS),and tumor necrosis factor(TNF)-αmRNA expression levels in hippocampus.Immunofluorescence was employed to observe microglial activation in the DG.Results Compared with Sham,CONV-RT10Gy and CONV-RT20Gy exhibited disorganized neuronal arrangements and blurred nucleoli in the DG;the number of Nissl body was reduced,but FLASH-RT10Gy and FLASH-RT20Gy alleviated these abnormalities.Moreover,FLASH-RT20Gy mitigated the upregulation of MDA and downregulation of GSH,GSH-PX,SOD,CAT,and OH^(-)levels in the hippocampus of mice subjected to CONV-RT20Gy.Additionally,FLASH-RT20Gy attenuated the upregulation of IL-1β,IL-6,iNOS,and TNF-αmRNA levels in hippocampus of mice subjected to CONV-RT20Gy and diminished microglial activation in the DG.Conclusion FLASH-RT mitigate the structural and functional disruptions in hippocampal neurons induced by CONV-RT and alleviate oxidative stress and inflammation in hippocampal tissue by reducing microglial activation.展开更多
BACKGROUND Current drugs primarily target inflammation control but do not reverse tissue remodeling changes for asthma.Human mesenchymal stem cells are known for their anti-inflammatory and tissue remodeling capabilit...BACKGROUND Current drugs primarily target inflammation control but do not reverse tissue remodeling changes for asthma.Human mesenchymal stem cells are known for their anti-inflammatory and tissue remodeling capabilities.However,limited research has explored the therapeutic impact of varying doses and frequencies of human umbilical cord blood-derived mesenchymal stem cells(HUC-MSCs)on established airway remodeling in experimental asthma.AIM To explore and optimize the dosage and administration frequency of HUC-MSCs in experimental models of ovalbumin(OVA)-induced asthma.METHODS BALB/c mice underwent sensitization and were challenged using OVA.Control animals were administered a saline solution following the same protocol.HUC-MSCs were identified using flow cytometry.HUC-MSCs at incremental dosages(1×105,2×105,4×105)were injected via tail veins on day 30(the second after the final stimulation).After comparing each group and determining the optimal dose,supplement the optimal dose twice on day 30 and day 33(the second and fifth day after the final stimulation).Bronchoalveolar lavage fluid(BALF)and serum were harvested for analysis of concentrations of interleukin-4(IL-4),IL-13,immunoglobulin E and interferon-gamma(IFN-γ)by enzyme-linked immunosorbent assay.Pharmacology of airways and lung functions were also evaluated to identify the optimal group.RESULTS The study shows that HUC-MSC transplantation ameliorates OVA-induced asthma by significantly reducing airway inflammation and obstruction in preclinical models.This effect is associated with decreased Th2 cytokines IL-4 and IL-13,and increased Th1 cytokine IFN-γ.The optimal dose of 2×105 cells/mouse was identified as the most effective in reducing local asthmatic airway inflammation and changing levels of IL-4,IL-13,and IFN-γin serum and BALF compared to other single doses of HUC-MSC.Multiple treatments with the medium dose(2×105 cells)of HUC-MSCs on days 30 and 33 yield the best pathological and lung function outcomes.However,double treatments do not reduce IL-4 and IL-13 expression or enhance IFN-γproduction in serum or BALF more effectively than a single medium dose.CONCLUSION HUC-MSCs effectively regulate pro-inflammatory mediators in serum and BALF,modulating airway remodeling and lung function.In this acute mouse asthma model,a single dosage of 2×105 is optimal,with more significant effects of decreasing airway obstruction requiring repeated administration.展开更多
A recent study by Zhang et al developed a neural network-based predictive model for estimating doses to the uninvolved liver during stereotactic body radiation therapy(SBRT)in liver cancer.The study reported a signifi...A recent study by Zhang et al developed a neural network-based predictive model for estimating doses to the uninvolved liver during stereotactic body radiation therapy(SBRT)in liver cancer.The study reported a significant advancement in personalized radiotherapy by improving accuracy and reducing treatment-related toxicity.The model demonstrated strong predictive performance with R-values above 0.8,indicating its potential to improve treatment consistency.However,concerns arise from the small sample size and exclusion criteria,which may limit generalizability.Future studies should incorporate larger,more diverse patient cohorts,explore potential confounding factors such as tumor characteristics and delivery technique variability,and address the long-term effects of SBRT.展开更多
This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing ...This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing an evolution from the current standard of rigid-body dose distribution verification.A 3D ex vivo biological lung motion simulation device(3D-BioLungEx)was designed to replicate human respiration.A radiotherapy plan of the patient was copied to the porcine lung,which was driven by 3D-BioLungEx to simulate various respiratory patterns that occur during treatment.To ensure anatomical consistency with the patient’s lung structure,during transmission,skin,skeleton,and organs were adjusted according to CT images of the porcine lung.The patient’s radiotherapy plan was then adapted to the porcine lung using the Monaco treatment planning system(TPS).Next,an iterative optimization and scatter inversion-based dose distribution retro-analysis algorithm(IOSI-BLDose)was developed to calculate the dose distribution during treatment.Gamma passing rates were used to quantify discrepancies between this dose distribution and that of the radiotherapy plan.When respiratory conditions were replicated,the passing rate reached up to 93.61%,while irregular breathing dropped it to 70%-90%,primarily due to amplitude changes.However,cycle variations had minimal impact.Compared to conventional rigid-body dose distribution verification,our method provides real-time biological feedback and more effectively captures motion-induced deviations.Accordingly,our biological in vivo 3D dose distribution verification has potential for improving treatment precision and enabling adaptive radiotherapy in clinical practice.展开更多
To monitor nuclear and radiation emergencies,it is crucial to obtain accurate in situ measurements of the environmentalγ radiation dose rate from key radionuclides,particularly for large radioactive surface sources.T...To monitor nuclear and radiation emergencies,it is crucial to obtain accurate in situ measurements of the environmentalγ radiation dose rate from key radionuclides,particularly for large radioactive surface sources.The methods currently used for measuring dose rates are inadequate for obtaining the dose rates of key radionuclides and have large angular response errors when monitoring surface sources.To address this practical problem,this study proposes three methods for measuring the dose rate:the weighted peak total ratio,mean value regression,and numerical integration methods.These methods are based on energy-spectrum measurement data,and they were theoretically derived and numerically evaluated.Finally,a 1-m-long hexagonal radioactive surface source was integrated into a larger surface source.In situ measurement experiments were conducted on a large radioactive surface source using a dose-rate meter and a portable HPGespectrometer to analyze the errors of the three aforementioned methods and verify their validity.展开更多
Tungsten is considered the most promising plasma-facing material for fusion reactors with exceptional performance.Under certain conditions,activated tungsten dust can be generated through plasma–wall interactions and...Tungsten is considered the most promising plasma-facing material for fusion reactors with exceptional performance.Under certain conditions,activated tungsten dust can be generated through plasma–wall interactions and released into the atmosphere.Activated tungsten migrates downward in the soil after atmospheric deposition.However,effective methods for evaluating the environmental dose of gamma rays emitted by activated tungsten are still lacking.Consequently,a method for evaluating the air-absorbed dose rate of activated tungsten dust was proposed considering soil attenuation.Key parameters including the mass attenuation coefficient and energy absorption build-up factor were determined for the main gamma ray energies of radionuclides within the activated tungsten dust.Additionally,air-absorbed dose rates were calculated by assuming that radioactive sources were located at different soil depths and radii.It was found that a soil depth of 50 cm significantly attenuated the environmental dose by 99.9%,whereas the air-absorbed dose rates within the horizontal distance of 500 cm accounted for 91%of the total dose rate.Therefore,this study underscored the importance of soil attenuation in environmental dose assessments,which must be carefully re-examined for the safety analysis of fusion reactors.展开更多
Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compar...Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.展开更多
The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for...The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for dosimetry in FLASHradiotherapy,making it crucial to monitor the dose at ultra-high dose rates accurately and in real time.In this study,the airpressure of the ionization chamber was reduced to perform real-time beam monitoring,and a Faraday cup was used for calibrationfor active dosimetry.To study the saturation effect of the ionization chamber,the drift,attachment,recombination,anddiffusion processes of the electron-ion pairs were modeled using finite-element analysis based on physical phenomenologicalprinciples,and the correction factor was calculated.The experimental results showed that the FLASH ionization chambermeasures good dose linearity at a dose rate of approximately 0.2 Gy/s.When the air pressure of the chamber was adjustedto 10 mbar,the response of the FLASH ionization chamber was linear at a dose rate of approximately 50 Gy/s,with theresiduals within 2%.Furthermore,by using physical phenomenology to resolve the process of electron-ion pair motion inthe sensitive volume of the ionization chamber,the analytical model better describes the saturation effect of carbon ions atultra-high dose rates.The maximum deviation in the calculated correction factor is less than 10%.We studied the saturationeffect in dose measurement,achieving accurate and fast dose and profile position measurement across different dose ratesin a wide range based on the Heavy Ion Research Facility in Lanzhou.展开更多
We read with great interest the recent article by Valenzuela et al.1titled“Dose-response effect of pre-exercise carbohydrates under muscle glycogen unavailability:Insights from McArdle disease”published in the Journ...We read with great interest the recent article by Valenzuela et al.1titled“Dose-response effect of pre-exercise carbohydrates under muscle glycogen unavailability:Insights from McArdle disease”published in the Journal of Sport and Health Science The study's exploration of the effects of varying carbohydrate(CHO)doses on exercise capacity in Mc Ardle disease,a condition characterized by complete muscle glycogen unavailability,is a significant contribution to the field of sports science and metabolic disorders.展开更多
Triple-negative bresst canær(TNBC)metastscis is particularly severe due to its aggressive nsture,leading to rapid disease progresion and significantly reduced survival rates.Rujifang(RJF),a traditional Chinese fo...Triple-negative bresst canær(TNBC)metastscis is particularly severe due to its aggressive nsture,leading to rapid disease progresion and significantly reduced survival rates.Rujifang(RJF),a traditional Chinese formula,has demonstrated potential anti-tumor effects and theability to inhibit TNBC metastasis.However,the efects af varying R.IF dors remain undear.This study utilized Laser-based in vino fow cytometry(IVFC)to monitor circulating tumor cells(CTCs)and evaluate the efficacy of R.IF at different doses.The results indicated that R.IF at the high dose inhibited both the number af CTC:and the formaton of metatatic foci more eflectively compared to the lower dose.TUNEL assays revealed that R.IF trentment promotes apoptosis of tumor cells,with a more pronounced effect observed at the higher dose.Immuno-fluorescence experiments demonstrated that administering a higher dose of R.IF suppreses theеxprescion of Kindlin-1 more effectively in the tumor microenvironment.Although higher doses showed enhanced efficacy,they might also lesd to an increase in side efects.These findings underscore the promise and challenges of using R.IF at high doses for anti-tumor therspy.They highlight the criticnl importance of optimizing the dose of R.JP in the treatment of TNBC and provide valuable insights for its dinical application.展开更多
The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extra...The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin, cornea, sclera, anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D (0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6 mm are also obtained with Cross's methods. They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.展开更多
The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg)...The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg) and immediate release tablets (IRMS, 20 mg). The plasma concentration of morphine was determined by GC MS. The pharmacokinetic parameters of controlled release tablets and immediate release tablets were calculated∶ C max was 19.38±3.80 and 21.27±6.21 ng/ml, t max was 2.36 ±0.37 h and 0.56±0.16 h, t 1/2β was 3.53±0.87 and 3.03±0.74 h, AUC was 145.15±17.65 and 93.08±16.65 ng/ml, respectively. The steady state plasma concentration of morphine sulphate in cancer patients after multiple doses was achieved, C max of CRMS and IRMS was 27.43±0.33 ng/ml and 22.68±0.16 ng/ml, C min of CRMS and IRMS was 19.45±1.44 ng/ml and 18.14±0.49 ng/ml, respectively.展开更多
目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs)...目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs),其余条件保持不变。比较A、B两组扫描方案的辐射剂量及所得图像的平均CT值、噪声、信号噪声比(SNR)、对比噪声比(CNR)、主观评分等。结果 A、B两组辐射剂量差异有统计学意义(t=-2.24,P=0.03)。与A组比较,B组有效剂量(ED)下降约23.15%;图像的平均CT值、噪声、SNR、CNR及主观评分比较差异无统计学意义(P>0.05)。结论应用双源CT CARE Dose 4D技术行儿童牙齿CT扫描,在降低辐射剂量的同时,不影响图像质量,值得临床推广。展开更多
To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcu...To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.展开更多
文摘BACKGROUND Primary ciliary dyskinesia(PCD)is a rare condition characterised by dysmotile,immotile,or absent cilia.As a result of the impairment in respiratory mucociliary clearance,patients with PCD typically develop neonatal respiratory distress,nasal congestion,otitis media and recurrent respiratory infections leading to bronchiectasis and structural lung changes.These changes have been shown by chest computed tomography(CT)to develop in infancy and early childhood.Recent development and refinement of radiation-reducing CT techniques have allowed significant radiation dose reductions,with chest CT doses now in the range of chest radiography(CR).AIM To evaluate the efficacy of ultra-low dose CT(ULDCT)chest in identifying pulmonary changes within a PCD paediatric patient cohort.METHODS Paediatric patients with PCD who presented for routine clinical outpatient follow-up within the study period,were eligible for inclusion in the study.ULDCT and CR were performed on these patients and the results compared.Comparison metrics included radiation dose,subjective and objective image quality and disease severity.RESULTS Six paediatric patients(mean age 9 years)underwent clinically indicated ULDCT chest examinations and CR for surveillance of their PCD.The mean effective dose was 0.08±0.02 mSv,a dose that approximates that of a frontal and lateral chest radiograph.The average Brody II score across the entire cohort was 12.92,with excellent interrater reliability and intra-class correlation coefficient(ICC)of 0.98.The average Chrispin-Norman score on CR was 1 with excellent inter-rater reliability and ICC of 0.92.CONCLUSION ULDCT demonstrates superior diagnostic capabilities,minimal radiation dose penalty,and high interobserver reliability in comparison to CR.Thus,we advocate for ULDCT to be the preferred modality for surveillance imaging in paediatric PCD.
文摘Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice were divided into five groups:Sham,CONV-RT10Gy,CONV-RT20Gy,FLASH-RT10Gy,and FLASH-RT20Gy.Three days post-irradiation,morphological changes in neurons within the dentate gyrus(DG),CA1,and CA3 were observed using hematoxylin and eosin and Nissl staining.The malondialdehyde(MDA),reduced glutathione(GSH),glutathione peroxidase(GSH-PX),superoxide dismutase(SOD),catalase(CAT),and hydroxyl radical(OH^(-))levels were measured using assay kits.Quantitative reverse transcription PCR was used to assess interleukin(IL)-1β,IL-6,inducible nitric oxide synthase(iNOS),and tumor necrosis factor(TNF)-αmRNA expression levels in hippocampus.Immunofluorescence was employed to observe microglial activation in the DG.Results Compared with Sham,CONV-RT10Gy and CONV-RT20Gy exhibited disorganized neuronal arrangements and blurred nucleoli in the DG;the number of Nissl body was reduced,but FLASH-RT10Gy and FLASH-RT20Gy alleviated these abnormalities.Moreover,FLASH-RT20Gy mitigated the upregulation of MDA and downregulation of GSH,GSH-PX,SOD,CAT,and OH^(-)levels in the hippocampus of mice subjected to CONV-RT20Gy.Additionally,FLASH-RT20Gy attenuated the upregulation of IL-1β,IL-6,iNOS,and TNF-αmRNA levels in hippocampus of mice subjected to CONV-RT20Gy and diminished microglial activation in the DG.Conclusion FLASH-RT mitigate the structural and functional disruptions in hippocampal neurons induced by CONV-RT and alleviate oxidative stress and inflammation in hippocampal tissue by reducing microglial activation.
基金Supported by the Joint Innovation Project Funds of Huaqiao University,No.2022YX001。
文摘BACKGROUND Current drugs primarily target inflammation control but do not reverse tissue remodeling changes for asthma.Human mesenchymal stem cells are known for their anti-inflammatory and tissue remodeling capabilities.However,limited research has explored the therapeutic impact of varying doses and frequencies of human umbilical cord blood-derived mesenchymal stem cells(HUC-MSCs)on established airway remodeling in experimental asthma.AIM To explore and optimize the dosage and administration frequency of HUC-MSCs in experimental models of ovalbumin(OVA)-induced asthma.METHODS BALB/c mice underwent sensitization and were challenged using OVA.Control animals were administered a saline solution following the same protocol.HUC-MSCs were identified using flow cytometry.HUC-MSCs at incremental dosages(1×105,2×105,4×105)were injected via tail veins on day 30(the second after the final stimulation).After comparing each group and determining the optimal dose,supplement the optimal dose twice on day 30 and day 33(the second and fifth day after the final stimulation).Bronchoalveolar lavage fluid(BALF)and serum were harvested for analysis of concentrations of interleukin-4(IL-4),IL-13,immunoglobulin E and interferon-gamma(IFN-γ)by enzyme-linked immunosorbent assay.Pharmacology of airways and lung functions were also evaluated to identify the optimal group.RESULTS The study shows that HUC-MSC transplantation ameliorates OVA-induced asthma by significantly reducing airway inflammation and obstruction in preclinical models.This effect is associated with decreased Th2 cytokines IL-4 and IL-13,and increased Th1 cytokine IFN-γ.The optimal dose of 2×105 cells/mouse was identified as the most effective in reducing local asthmatic airway inflammation and changing levels of IL-4,IL-13,and IFN-γin serum and BALF compared to other single doses of HUC-MSC.Multiple treatments with the medium dose(2×105 cells)of HUC-MSCs on days 30 and 33 yield the best pathological and lung function outcomes.However,double treatments do not reduce IL-4 and IL-13 expression or enhance IFN-γproduction in serum or BALF more effectively than a single medium dose.CONCLUSION HUC-MSCs effectively regulate pro-inflammatory mediators in serum and BALF,modulating airway remodeling and lung function.In this acute mouse asthma model,a single dosage of 2×105 is optimal,with more significant effects of decreasing airway obstruction requiring repeated administration.
文摘A recent study by Zhang et al developed a neural network-based predictive model for estimating doses to the uninvolved liver during stereotactic body radiation therapy(SBRT)in liver cancer.The study reported a significant advancement in personalized radiotherapy by improving accuracy and reducing treatment-related toxicity.The model demonstrated strong predictive performance with R-values above 0.8,indicating its potential to improve treatment consistency.However,concerns arise from the small sample size and exclusion criteria,which may limit generalizability.Future studies should incorporate larger,more diverse patient cohorts,explore potential confounding factors such as tumor characteristics and delivery technique variability,and address the long-term effects of SBRT.
基金supported by the National Natural Science Foundation of China(No.62371243)National Key Research and Development Program of China(No.2025YFC2427600)+4 种基金the Jiangsu Provincial Key Research and Development Program Social Development Project(No.BE2022720)the Natural Science Foundation of Jiangsu Province(No.BK20231190)Jiangsu Provincial Medical Key Discipline Cultivation Unit of Oncology Therapeutics(Radiotherapy)(No.JSDW202237)Changzhou Social Development Program(Nos.CE20235063 and CJ20244020)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.JX13614239).
文摘This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing an evolution from the current standard of rigid-body dose distribution verification.A 3D ex vivo biological lung motion simulation device(3D-BioLungEx)was designed to replicate human respiration.A radiotherapy plan of the patient was copied to the porcine lung,which was driven by 3D-BioLungEx to simulate various respiratory patterns that occur during treatment.To ensure anatomical consistency with the patient’s lung structure,during transmission,skin,skeleton,and organs were adjusted according to CT images of the porcine lung.The patient’s radiotherapy plan was then adapted to the porcine lung using the Monaco treatment planning system(TPS).Next,an iterative optimization and scatter inversion-based dose distribution retro-analysis algorithm(IOSI-BLDose)was developed to calculate the dose distribution during treatment.Gamma passing rates were used to quantify discrepancies between this dose distribution and that of the radiotherapy plan.When respiratory conditions were replicated,the passing rate reached up to 93.61%,while irregular breathing dropped it to 70%-90%,primarily due to amplitude changes.However,cycle variations had minimal impact.Compared to conventional rigid-body dose distribution verification,our method provides real-time biological feedback and more effectively captures motion-induced deviations.Accordingly,our biological in vivo 3D dose distribution verification has potential for improving treatment precision and enabling adaptive radiotherapy in clinical practice.
文摘To monitor nuclear and radiation emergencies,it is crucial to obtain accurate in situ measurements of the environmentalγ radiation dose rate from key radionuclides,particularly for large radioactive surface sources.The methods currently used for measuring dose rates are inadequate for obtaining the dose rates of key radionuclides and have large angular response errors when monitoring surface sources.To address this practical problem,this study proposes three methods for measuring the dose rate:the weighted peak total ratio,mean value regression,and numerical integration methods.These methods are based on energy-spectrum measurement data,and they were theoretically derived and numerically evaluated.Finally,a 1-m-long hexagonal radioactive surface source was integrated into a larger surface source.In situ measurement experiments were conducted on a large radioactive surface source using a dose-rate meter and a portable HPGespectrometer to analyze the errors of the three aforementioned methods and verify their validity.
基金supported by the National Natural Science Foundation of China(No.12375314)。
文摘Tungsten is considered the most promising plasma-facing material for fusion reactors with exceptional performance.Under certain conditions,activated tungsten dust can be generated through plasma–wall interactions and released into the atmosphere.Activated tungsten migrates downward in the soil after atmospheric deposition.However,effective methods for evaluating the environmental dose of gamma rays emitted by activated tungsten are still lacking.Consequently,a method for evaluating the air-absorbed dose rate of activated tungsten dust was proposed considering soil attenuation.Key parameters including the mass attenuation coefficient and energy absorption build-up factor were determined for the main gamma ray energies of radionuclides within the activated tungsten dust.Additionally,air-absorbed dose rates were calculated by assuming that radioactive sources were located at different soil depths and radii.It was found that a soil depth of 50 cm significantly attenuated the environmental dose by 99.9%,whereas the air-absorbed dose rates within the horizontal distance of 500 cm accounted for 91%of the total dose rate.Therefore,this study underscored the importance of soil attenuation in environmental dose assessments,which must be carefully re-examined for the safety analysis of fusion reactors.
文摘Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.
文摘The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for dosimetry in FLASHradiotherapy,making it crucial to monitor the dose at ultra-high dose rates accurately and in real time.In this study,the airpressure of the ionization chamber was reduced to perform real-time beam monitoring,and a Faraday cup was used for calibrationfor active dosimetry.To study the saturation effect of the ionization chamber,the drift,attachment,recombination,anddiffusion processes of the electron-ion pairs were modeled using finite-element analysis based on physical phenomenologicalprinciples,and the correction factor was calculated.The experimental results showed that the FLASH ionization chambermeasures good dose linearity at a dose rate of approximately 0.2 Gy/s.When the air pressure of the chamber was adjustedto 10 mbar,the response of the FLASH ionization chamber was linear at a dose rate of approximately 50 Gy/s,with theresiduals within 2%.Furthermore,by using physical phenomenology to resolve the process of electron-ion pair motion inthe sensitive volume of the ionization chamber,the analytical model better describes the saturation effect of carbon ions atultra-high dose rates.The maximum deviation in the calculated correction factor is less than 10%.We studied the saturationeffect in dose measurement,achieving accurate and fast dose and profile position measurement across different dose ratesin a wide range based on the Heavy Ion Research Facility in Lanzhou.
文摘We read with great interest the recent article by Valenzuela et al.1titled“Dose-response effect of pre-exercise carbohydrates under muscle glycogen unavailability:Insights from McArdle disease”published in the Journal of Sport and Health Science The study's exploration of the effects of varying carbohydrate(CHO)doses on exercise capacity in Mc Ardle disease,a condition characterized by complete muscle glycogen unavailability,is a significant contribution to the field of sports science and metabolic disorders.
基金supported by the National Key Re-search and Development Program of China(2021YFF0502900,2019YFC1604604)the grant of Peak Climbing Project of Foshan Hospital of Tra-ditional Chinese Medicine,Traditional Chinese Medicine Bureat of Guangdong Province Project(No.20213018)+2 种基金the Special Fund for Research on National Major Research Instruuments of China(Grant No.62027824)Scientific Research Fund of Education Department of Yunnan Province(2023Y0619)Biomedical Projects of Yun-nan Key Science and Technology Program(202302AA310046).
文摘Triple-negative bresst canær(TNBC)metastscis is particularly severe due to its aggressive nsture,leading to rapid disease progresion and significantly reduced survival rates.Rujifang(RJF),a traditional Chinese formula,has demonstrated potential anti-tumor effects and theability to inhibit TNBC metastasis.However,the efects af varying R.IF dors remain undear.This study utilized Laser-based in vino fow cytometry(IVFC)to monitor circulating tumor cells(CTCs)and evaluate the efficacy of R.IF at different doses.The results indicated that R.IF at the high dose inhibited both the number af CTC:and the formaton of metatatic foci more eflectively compared to the lower dose.TUNEL assays revealed that R.IF trentment promotes apoptosis of tumor cells,with a more pronounced effect observed at the higher dose.Immuno-fluorescence experiments demonstrated that administering a higher dose of R.IF suppreses theеxprescion of Kindlin-1 more effectively in the tumor microenvironment.Although higher doses showed enhanced efficacy,they might also lesd to an increase in side efects.These findings underscore the promise and challenges of using R.IF at high doses for anti-tumor therspy.They highlight the criticnl importance of optimizing the dose of R.JP in the treatment of TNBC and provide valuable insights for its dinical application.
文摘The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin, cornea, sclera, anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D (0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6 mm are also obtained with Cross's methods. They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.
文摘The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg) and immediate release tablets (IRMS, 20 mg). The plasma concentration of morphine was determined by GC MS. The pharmacokinetic parameters of controlled release tablets and immediate release tablets were calculated∶ C max was 19.38±3.80 and 21.27±6.21 ng/ml, t max was 2.36 ±0.37 h and 0.56±0.16 h, t 1/2β was 3.53±0.87 and 3.03±0.74 h, AUC was 145.15±17.65 and 93.08±16.65 ng/ml, respectively. The steady state plasma concentration of morphine sulphate in cancer patients after multiple doses was achieved, C max of CRMS and IRMS was 27.43±0.33 ng/ml and 22.68±0.16 ng/ml, C min of CRMS and IRMS was 19.45±1.44 ng/ml and 18.14±0.49 ng/ml, respectively.
文摘目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs),其余条件保持不变。比较A、B两组扫描方案的辐射剂量及所得图像的平均CT值、噪声、信号噪声比(SNR)、对比噪声比(CNR)、主观评分等。结果 A、B两组辐射剂量差异有统计学意义(t=-2.24,P=0.03)。与A组比较,B组有效剂量(ED)下降约23.15%;图像的平均CT值、噪声、SNR、CNR及主观评分比较差异无统计学意义(P>0.05)。结论应用双源CT CARE Dose 4D技术行儿童牙齿CT扫描,在降低辐射剂量的同时,不影响图像质量,值得临床推广。
文摘To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.
