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
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
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
Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microgli...Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microglia-dependent inflammation,leading to neuronal damage,a lowered seizure threshold,and the emergence of spontaneous recurrent seizures(SRS).Extensive evidence from our laboratory suggests that dextromethorphan(DM),even in ultra-low doses,has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease.Our results showed that administration of DM(10 ng/kg per day;subcutaneously via osmotic minipump for 4 weeks)significantly mitigated the residual effects of KA,including the frequency of SRS and seizure susceptibility.In addition,DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss.We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91^(phox) and p47^(phox) proteins in KA-induced chronic TLE rats.Notably,even after discontinuation of DM treatment,ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects,which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies.展开更多
Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxid...Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.展开更多
BACKGROUND Helicobacter pylori(H.pylori)eradication rates have fallen globally,likely in large part due to increasing antibiotic resistance to traditional therapy.In areas of high clarithromycin and metronidazole resi...BACKGROUND Helicobacter pylori(H.pylori)eradication rates have fallen globally,likely in large part due to increasing antibiotic resistance to traditional therapy.In areas of high clarithromycin and metronidazole resistance such as ours,Maastricht VI guidelines suggest high dose amoxicillin dual therapy(HDADT)can be considered,subject to evidence for local efficacy.In this study we assess efficacy of HDADT therapy for H.pylori eradication in an Irish cohort.AIM To assess the efficacy of HDADT therapy for H.pylori eradication in an Irish cohort as both first line,and subsequent therapy for patients diagnosed with H.pylori.METHODS All patients testing positive for H.pylori in a tertiary centre were treated prospectively with HDADT(amoxicillin 1 g tid and esomeprazole 40 mg bid×14 d)over a period of 8 months.Eradication was confirmed with Urea Breath Test at least 4 wk after cessation of therapy.A delta-over-baseline>4%was considered positive.Patient demographics and treatment outcomes were recorded,analysed and controlled for basic demographics and prior H.pylori treatment.RESULTS One hundred and ninety-eight patients were identified with H.pylori infection,10 patients were excluded due to penicillin allergy and 38 patients refused follow up testing.In all 139 were included in the analysis,55%(n=76)were female,mean age was 46.6 years.Overall,93(67%)of patients were treatment-naïve and 46(33%)had received at least one previous course of treatment.The groups were statistically similar.Self-reported compliance with HDADT was 97%,mild side-effects occurred in 7%.There were no serious adverse drug reactions.Overall the eradication rate for our cohort was 56%(78/139).Eradication rates were worse for those with previous treatment[43%(20/46)vs 62%(58/93),P=0.0458,odds ratio=2.15].Age and Gender had no effect on eradication status.CONCLUSION Overall eradication rates with HDADT were disappointing.Despite being a simple and possibly better tolerated regime,these results do not support its routine use in a high dual resistance country.Further investigation of other regimens to achieve the>90%eradication target is needed.展开更多
Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID eff...Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was proposed.The digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional area.Each of these three parts was separately modeled.Using the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using VHDL-AMS.In the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area models.Furthermore,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital IC.TID experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose point.This confirms the practicality and accuracy of the proposed modeling method.The TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.展开更多
BACKGROUND Carbon ion radiotherapy(CIRT)is currently used to treat prostate cancer.Rectal bleeding is a major cause of toxicity even with CIRT.However,to date,a correlation between the dose and volume parameters of th...BACKGROUND Carbon ion radiotherapy(CIRT)is currently used to treat prostate cancer.Rectal bleeding is a major cause of toxicity even with CIRT.However,to date,a correlation between the dose and volume parameters of the 12 fractions of CIRT for prostate cancer and rectal bleeding has not been shown.Similarly,the clinical risk factors for rectal bleeding were absent after 12 fractions of CIRT.AIM To identify the risk factors for rectal bleeding in 12 fractions of CIRT for prostate cancer.METHODS Among 259 patients who received 51.6 Gy[relative biological effectiveness(RBE)],in 12 fractions of CIRT,15 had grade 1(5.8%)and nine had grade 2 rectal bleeding(3.5%).The dose-volume parameters included the volume(cc)of the rectum irradiated with at least x Gy(RBE)(Vx)and the minimum dose in the most irradiated x cc normal rectal volume(Dx).RESULTS The mean values of D6cc,D2cc,V10 Gy(RBE),V20 Gy(RBE),V30 Gy(RBE),and V40 Gy(RBE)were significantly higher in the patients with rectal bleeding than in those without.The cutoff values were D6cc=34.34 Gy(RBE),D2cc=46.46 Gy(RBE),V10 Gy(RBE)=9.85 cc,V20 Gy(RBE)=7.00 cc,V30 Gy(RBE)=6.91 cc,and V40 Gy(RBE)=4.26 cc.The D2cc,V10 Gy(RBE),and V20 Gy(RBE)cutoff values were significant predictors of grade 2 rectal bleeding.CONCLUSION The above dose-volume parameters may serve as guidelines for preventing rectal bleeding after 12 fractions of CIRT for prostate cancer.展开更多
Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quanti...Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.展开更多
Background: World Health Organization recommends the implementation of contact tracing and Leprosy Post Exposure prophylaxis (LPEP) to interrupt the chain of transmission. To accelerate the uptake of this recommendati...Background: World Health Organization recommends the implementation of contact tracing and Leprosy Post Exposure prophylaxis (LPEP) to interrupt the chain of transmission. To accelerate the uptake of this recommendation, a cross-sectional study among contacts of leprosy patients was conducted to investigate the feasibility of integrating leprosy systematic contact tracing and post-exposure prophylaxis (PEP) into the routine leprosy control program. Methods: This was a mixed methods cross-sectional study. The study was implemented in Kumi, Ngora, Serere, Soroti, Budaka and Kibuku Districts. Results: The 45 enrolled index patients (97.8% of the registered) identified a total of 135 contacts, of which 134 (99·2%) consented and were screened. Among them, one new leprosy patient was identified and started on treatment with multidrug therapy (MDT). All the eligible contacts, received the prophylactic treatment with Single Dose Rifampicin (SDR). Overall, SDR was administered to 133(98.5% of the listed contacts) with no adverse event reported. Factors associated with successful contact investigation and management included: Involvement of index patients, health care workers during the contact screening and SDR A administration, counselling of the index patients and contacts by the health care works, LPEP being administered as Directly observed Therapy (DOT) among others. Results Interpretation: The integration of leprosy post-exposure prophylaxis with administration of SDR and contact tracing is feasible, generally accepted by the patient, their contacts and health workers and can be integrated into the National Leprosy control programmes with minimal additional efforts once contact tracing has been established. Therefore, we recommend integration of administration of SDR in to the routine leprosy control program.展开更多
Helicobacter pylori(H.pylori)infections may cause chronic gastritis,peptic ulcer disease,gastric cancers,and other conditions outside of the gastrointestinal tract.Hence,it is important to diagnose and treat it early....Helicobacter pylori(H.pylori)infections may cause chronic gastritis,peptic ulcer disease,gastric cancers,and other conditions outside of the gastrointestinal tract.Hence,it is important to diagnose and treat it early.H.pylori is resistant to certain drugs in traditional eradication therapy,so alternative therapy protocols are needed,such as high-dose amoxicillin dual therapy(HDADT).This article aims to comment on a recent paper by Costigan et al in the World Journal of Clinical Cases.In this study,the authors recruited 139 patients diagnosed with H.pylori,all treated with HDADT.Of these,93 were treatment-naïve and 46 had received at least one alternative treatment in the past.Four weeks after the end of the treatment,the urea breath test was administered to estimate the eradication rate.The total eradication rate was 56%(78/139),62%for the treatment-naïve arm and 43%for the previous treatment arm,thus indicating a lower success rate for the arm that had previously received a different treatment regimen.In conclusion,a therapeutic approach with first-line HDADT may potentially be a better treat-ment,but the results are not sufficient to recommend the use of this regimen in a country with high levels of dual resistance.展开更多
Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irra...Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.展开更多
Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fastin...Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fasting conditions. Methods: This was a phase I, randomized, single-dose, two-period, two-sequence, crossover study to evaluate the bioequivalence (BE) profiles of two fixed-dose combinations (FDCs) of empagliflozin/metformin. Cmax, AUC0-t and AUC0-∞ from test and reference formulations were evaluated to access BE. The plasma concentrations were measured using a validated liquid chromatography-mass spectrometry (LC-MS/MS) method. Of the 24 subjects enrolled, 23 completed both periods of the study. The two formulations test and reference were considered bioequivalent if 90% confidence interval (CI) fell within 80.00% - 125.00% for Cmax, AUC0-t and AUC0-∞. Tolerability and safety were assessed throughout the study. Results: The pharmacokinetic (PK) parameters were similar between the test product (T) and reference product (R) Synjardy®. The 90% CI of the test/reference ratios of log-transformed PK parameters point estimates was Cmax: 89.87% (85.68% - 94.27%), AUC0-t: 87.91% (83.65% - 92.39%) and AUC0-∞: 87.16% (82.80% - 91.75%) to empagliflozin and Cmax: 92.19% (87.95% - 96.65%), AUC0-t: 91.38% (84.42% - 98.91%) and AUC0-∞: 93.78% (83.82% - 104.93%) to metformin respectively (90% CI for all PK parameters fell within 80.00% - 125.00%). Conclusion: Our results demonstrated BE between the test and reference formulations of oral tablets of empagliflozin 12.5 mg/metformin 1000 mg (FDC) in healthy male subjects under fasting conditions.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.
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.
文摘目的:探讨在新生儿胸部CT检查中,结合使用低管电压、固定管电流以及不同权重的iDose4重建技术对图像质量的影响,并评估其可行性。方法:搜集80例行CT检查的新生儿,随机分到A、B两组,A组采用自动曝光控制技术,B组采用固定管电流扫描(33 mA),采用iDose^(4)重建法重建出1~7级不同权重的肺窗和纵隔窗图像,并对比分析图像质量。记录患儿的CTDIVOL,后依据回归模型计算出体型特异性剂量估算值(size specific dose estimate,SSDE),并对比分析。结果:A、B两组患儿iDose^(4)重建算法的最佳权重肺窗为3级,纵隔窗为4级;A、B组患儿CTDIVOL分别为(1.04±0.21)mGy和(0.91±0.18)mGy,A组较B组高12.5%(t=2.17,P=0.04);A、B组患儿的SSDE分别为(2.41±0.36)mGy和(2.07±0.32)mGy,A组较B组高15.4%(t=3.19,P<0.05);A、B组患儿CTDIVOL离散度分别为20.2%(0.21/1.04)和19.8%(0.18/0.91),A、B组患儿SSDE离散度分别为14.5%(0.36/2.41)和15.5%(0.32/2.07)。结论:在新生儿CT检查时推荐使用低管电压、低固定管电流及适当的重建算法权重相结合的方法进行扫描,同时,推荐采用SSDE评估新生儿的辐射剂量。
基金supported by the National Major Scientific and Technological Special Project for Significant New Drugs Development(2019zx09301102)the Project of Liaoning Provincial Department of Education(LJKZ0826)the Open Project of National and Local Joint Engineering Research Center for Drug Research and Development of Neurodegenerative Diseases(2022GCYJZX-YB02).
文摘Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microglia-dependent inflammation,leading to neuronal damage,a lowered seizure threshold,and the emergence of spontaneous recurrent seizures(SRS).Extensive evidence from our laboratory suggests that dextromethorphan(DM),even in ultra-low doses,has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease.Our results showed that administration of DM(10 ng/kg per day;subcutaneously via osmotic minipump for 4 weeks)significantly mitigated the residual effects of KA,including the frequency of SRS and seizure susceptibility.In addition,DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss.We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91^(phox) and p47^(phox) proteins in KA-induced chronic TLE rats.Notably,even after discontinuation of DM treatment,ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects,which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies.
基金supported by Guangzhou Science and Technology Planning Project(2023A04J0131)Special fund for scientific innovation strategyconstruction of high level Academy of Agriculture Science(R2020PY-JG009,R2022PY-QY007,202106TD)+2 种基金China Agriculture Research System-CARS-35the Project of Swine Innovation Team in Guangdong Modern Agricultural Research System(2022KJ126)Special Fund for Rural Revitalization Strategy of Guangdong(2023TS-3),China。
文摘Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.
文摘BACKGROUND Helicobacter pylori(H.pylori)eradication rates have fallen globally,likely in large part due to increasing antibiotic resistance to traditional therapy.In areas of high clarithromycin and metronidazole resistance such as ours,Maastricht VI guidelines suggest high dose amoxicillin dual therapy(HDADT)can be considered,subject to evidence for local efficacy.In this study we assess efficacy of HDADT therapy for H.pylori eradication in an Irish cohort.AIM To assess the efficacy of HDADT therapy for H.pylori eradication in an Irish cohort as both first line,and subsequent therapy for patients diagnosed with H.pylori.METHODS All patients testing positive for H.pylori in a tertiary centre were treated prospectively with HDADT(amoxicillin 1 g tid and esomeprazole 40 mg bid×14 d)over a period of 8 months.Eradication was confirmed with Urea Breath Test at least 4 wk after cessation of therapy.A delta-over-baseline>4%was considered positive.Patient demographics and treatment outcomes were recorded,analysed and controlled for basic demographics and prior H.pylori treatment.RESULTS One hundred and ninety-eight patients were identified with H.pylori infection,10 patients were excluded due to penicillin allergy and 38 patients refused follow up testing.In all 139 were included in the analysis,55%(n=76)were female,mean age was 46.6 years.Overall,93(67%)of patients were treatment-naïve and 46(33%)had received at least one previous course of treatment.The groups were statistically similar.Self-reported compliance with HDADT was 97%,mild side-effects occurred in 7%.There were no serious adverse drug reactions.Overall the eradication rate for our cohort was 56%(78/139).Eradication rates were worse for those with previous treatment[43%(20/46)vs 62%(58/93),P=0.0458,odds ratio=2.15].Age and Gender had no effect on eradication status.CONCLUSION Overall eradication rates with HDADT were disappointing.Despite being a simple and possibly better tolerated regime,these results do not support its routine use in a high dual resistance country.Further investigation of other regimens to achieve the>90%eradication target is needed.
基金This work was supported by the special fund of the State Key Laboratory of Intense Pulsed Radiation Simulation and Effect(No.SKLIPR2011).
文摘Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was proposed.The digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional area.Each of these three parts was separately modeled.Using the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using VHDL-AMS.In the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area models.Furthermore,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital IC.TID experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose point.This confirms the practicality and accuracy of the proposed modeling method.The TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.
文摘BACKGROUND Carbon ion radiotherapy(CIRT)is currently used to treat prostate cancer.Rectal bleeding is a major cause of toxicity even with CIRT.However,to date,a correlation between the dose and volume parameters of the 12 fractions of CIRT for prostate cancer and rectal bleeding has not been shown.Similarly,the clinical risk factors for rectal bleeding were absent after 12 fractions of CIRT.AIM To identify the risk factors for rectal bleeding in 12 fractions of CIRT for prostate cancer.METHODS Among 259 patients who received 51.6 Gy[relative biological effectiveness(RBE)],in 12 fractions of CIRT,15 had grade 1(5.8%)and nine had grade 2 rectal bleeding(3.5%).The dose-volume parameters included the volume(cc)of the rectum irradiated with at least x Gy(RBE)(Vx)and the minimum dose in the most irradiated x cc normal rectal volume(Dx).RESULTS The mean values of D6cc,D2cc,V10 Gy(RBE),V20 Gy(RBE),V30 Gy(RBE),and V40 Gy(RBE)were significantly higher in the patients with rectal bleeding than in those without.The cutoff values were D6cc=34.34 Gy(RBE),D2cc=46.46 Gy(RBE),V10 Gy(RBE)=9.85 cc,V20 Gy(RBE)=7.00 cc,V30 Gy(RBE)=6.91 cc,and V40 Gy(RBE)=4.26 cc.The D2cc,V10 Gy(RBE),and V20 Gy(RBE)cutoff values were significant predictors of grade 2 rectal bleeding.CONCLUSION The above dose-volume parameters may serve as guidelines for preventing rectal bleeding after 12 fractions of CIRT for prostate cancer.
基金supported by the National Key R&D Program of China(No.2022YFC2402300)National Natural Science Foundation of China(No.12075330)。
文摘Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.
文摘Background: World Health Organization recommends the implementation of contact tracing and Leprosy Post Exposure prophylaxis (LPEP) to interrupt the chain of transmission. To accelerate the uptake of this recommendation, a cross-sectional study among contacts of leprosy patients was conducted to investigate the feasibility of integrating leprosy systematic contact tracing and post-exposure prophylaxis (PEP) into the routine leprosy control program. Methods: This was a mixed methods cross-sectional study. The study was implemented in Kumi, Ngora, Serere, Soroti, Budaka and Kibuku Districts. Results: The 45 enrolled index patients (97.8% of the registered) identified a total of 135 contacts, of which 134 (99·2%) consented and were screened. Among them, one new leprosy patient was identified and started on treatment with multidrug therapy (MDT). All the eligible contacts, received the prophylactic treatment with Single Dose Rifampicin (SDR). Overall, SDR was administered to 133(98.5% of the listed contacts) with no adverse event reported. Factors associated with successful contact investigation and management included: Involvement of index patients, health care workers during the contact screening and SDR A administration, counselling of the index patients and contacts by the health care works, LPEP being administered as Directly observed Therapy (DOT) among others. Results Interpretation: The integration of leprosy post-exposure prophylaxis with administration of SDR and contact tracing is feasible, generally accepted by the patient, their contacts and health workers and can be integrated into the National Leprosy control programmes with minimal additional efforts once contact tracing has been established. Therefore, we recommend integration of administration of SDR in to the routine leprosy control program.
文摘Helicobacter pylori(H.pylori)infections may cause chronic gastritis,peptic ulcer disease,gastric cancers,and other conditions outside of the gastrointestinal tract.Hence,it is important to diagnose and treat it early.H.pylori is resistant to certain drugs in traditional eradication therapy,so alternative therapy protocols are needed,such as high-dose amoxicillin dual therapy(HDADT).This article aims to comment on a recent paper by Costigan et al in the World Journal of Clinical Cases.In this study,the authors recruited 139 patients diagnosed with H.pylori,all treated with HDADT.Of these,93 were treatment-naïve and 46 had received at least one alternative treatment in the past.Four weeks after the end of the treatment,the urea breath test was administered to estimate the eradication rate.The total eradication rate was 56%(78/139),62%for the treatment-naïve arm and 43%for the previous treatment arm,thus indicating a lower success rate for the arm that had previously received a different treatment regimen.In conclusion,a therapeutic approach with first-line HDADT may potentially be a better treat-ment,but the results are not sufficient to recommend the use of this regimen in a country with high levels of dual resistance.
文摘Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.
文摘Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fasting conditions. Methods: This was a phase I, randomized, single-dose, two-period, two-sequence, crossover study to evaluate the bioequivalence (BE) profiles of two fixed-dose combinations (FDCs) of empagliflozin/metformin. Cmax, AUC0-t and AUC0-∞ from test and reference formulations were evaluated to access BE. The plasma concentrations were measured using a validated liquid chromatography-mass spectrometry (LC-MS/MS) method. Of the 24 subjects enrolled, 23 completed both periods of the study. The two formulations test and reference were considered bioequivalent if 90% confidence interval (CI) fell within 80.00% - 125.00% for Cmax, AUC0-t and AUC0-∞. Tolerability and safety were assessed throughout the study. Results: The pharmacokinetic (PK) parameters were similar between the test product (T) and reference product (R) Synjardy®. The 90% CI of the test/reference ratios of log-transformed PK parameters point estimates was Cmax: 89.87% (85.68% - 94.27%), AUC0-t: 87.91% (83.65% - 92.39%) and AUC0-∞: 87.16% (82.80% - 91.75%) to empagliflozin and Cmax: 92.19% (87.95% - 96.65%), AUC0-t: 91.38% (84.42% - 98.91%) and AUC0-∞: 93.78% (83.82% - 104.93%) to metformin respectively (90% CI for all PK parameters fell within 80.00% - 125.00%). Conclusion: Our results demonstrated BE between the test and reference formulations of oral tablets of empagliflozin 12.5 mg/metformin 1000 mg (FDC) in healthy male subjects under fasting conditions.
