Objective:To analyze the clinical effect of high-dose citrate in segmental extracorporeal anticoagulation for high-throughput hemodialysis.Methods:The subjects included in this study were admitted to the hospital for ...Objective:To analyze the clinical effect of high-dose citrate in segmental extracorporeal anticoagulation for high-throughput hemodialysis.Methods:The subjects included in this study were admitted to the hospital for maintenance hemodialysis treatment from January 2021 to January 2023.All patients had a high risk of bleeding and received 4%trisodium citrate anticoagulant treatment,administered at a rate of 200 mL/h before and after the dialyzer.The anticoagulant effects achieved by the patients were observed and analyzed.Results:The total number of patients who received high-dose segmented citrate extracorporeal anticoagulation dialysis treatment was 50,with each patient undergoing 100 treatments.During the treatment,2 patients had to end the treatment early due to transmembrane pressure exceeding 30 mmHg and an increase in venous pressure exceeding 250 mmHg;the treatment times for these patients were 20 minutes and 200 minutes,respectively.The remaining patients successfully completed the 4-hour treatment.Blood pH and calcium ion concentration in the venous pot were monitored.It was observed that before dialysis,after 2 hours of dialysis,and at the end of dialysis,the blood pH of the patients remained within a relatively normal range.Although some patient levels changed after dialysis,they remained within the normal range.No adverse reactions(such as numbness of the limbs or convulsions)were observed during the anticoagulant treatment.Conclusion:Administering 4%trisodium citrate at a rate of 200 mL/h before and after the dialyzer achieves a good anticoagulant effect,maintains the patient’s blood gas levels within the normal range at the end of dialysis,and causes no adverse reactions.展开更多
A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,fr...A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,from which the total ionizing dose(TID) and the synergistic damage mechanism of MRAM were analyzed.In addition,DC,AC,and functional parameters of the memory were tested under irradiation and annealing via a very large-scale integrated circuit test system.The radiation-sensitive parameters were obtained through analyzing the data.Because of the magnetic field applied on the MRAM while testing the synergistic effects,shallow trench isolation leakage and Frenkel–Poole emission due to synergistic effects were smaller than that of TID,and hence radiation damage of the synergistic effects was also lower.展开更多
This work researched the impact of total dose irradiation on the threshold voltage of N-type metal oxide semiconductor field effect transistors(nMOSFETs) in silicon-on-insulator(SOI) technology.Using the subthreshold ...This work researched the impact of total dose irradiation on the threshold voltage of N-type metal oxide semiconductor field effect transistors(nMOSFETs) in silicon-on-insulator(SOI) technology.Using the subthreshold separation technology,the factor causing the threshold voltage shift was divided into two parts:trapped oxide charges and interface states,the effects of which are presented under irradiation.Furthermore,by analyzing the data,the threshold voltage shows a negative shift at first and then turns to positive shift when irradiation dose is lower.Additionally,the influence of the dose rate effects on threshold voltage is discussed.The research results show that the threshold voltage shift is more significant in low dose rate conditions,even for a low dose of100 krad(Si).The degeneration value of threshold voltage is 23.4%and 58.0%for the front-gate and the back-gate at the low dose rate,respectively.展开更多
Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific d...Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific discovery approach.The total ionizing dose(TID)effects usually cause gain degradation of bipolar junction transistors(BJTs),leading to functional failures of bipolar integrated circuits.Currently,many experiments of TID effects on BJTs have been conducted at different laboratories worldwide,producing a large amount of experimental data which provides a wealth of information.However,it is difficult to utilize these data effectively.In this study,we proposed a new artificial neural network(ANN)approach to analyze the experimental data of TID effects on BJTs An ANN model was built and trained using data collected from different experiments.The results indicate that the proposed ANN model has advantages in capturing nonlinear correlations and predicting the data.The trained ANN model suggests that the TID hardness of a BJT tends to increase with base current I.A possible cause for this finding was analyzed and confirmed through irradiation experiments.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
The influence of combined total ionization dose(TID)and radiated electromagnetic interference(EMI)in a commercial analog-to-digital converter(ADC)was studied.The degradation of the direct-current response,the static p...The influence of combined total ionization dose(TID)and radiated electromagnetic interference(EMI)in a commercial analog-to-digital converter(ADC)was studied.The degradation of the direct-current response,the static parameters,and the dynamic parameters caused by the TID and EMI separately and synergistically is presented.The experimental results demonstrate that the increase in TID intensifies data error and the signal-tonoise ratio(SNR)degradation caused by radiated EMI.The cumulative distribution function of EMI failure with respect to data error and SNR with different TIDs was extracted.The decreasing trend of the threshold was acquired with a small sample size of five for each TID group.The result indicates that the ADC is more sensitive in a compound radiation environment.展开更多
In order to prevent severe pollution by de-icing salt on greenery along urban roads, a half lethal dose (LD_50)for a plant population was confirmed through stress simulation of chloride de-icing salt on Euonymus jap...In order to prevent severe pollution by de-icing salt on greenery along urban roads, a half lethal dose (LD_50)for a plant population was confirmed through stress simulation of chloride de-icing salt on Euonymus japonicus, with an ianalysis of physiological changes, statistics on mortality rate on plant populations and mathematic modeling during a 30- day subacute toxicity test. The results indicate that a significant positive correlation in the early stages and a significant negative correlation in the later stages were observed between the amount of chlorophyll a and b in plants and a cumulative dose of de-icing salt. The amounts of free proline in plants and the dose of de-icing salt were positively correlated Over the entire period. No significant correlation in the initial stage, but a significant negative correlation in later stages was observed between the soluble protein and the dose of de-icing salt. LDs0 of this chloride agent on E. japonicus is 5 kg.(L·m2)-1 over 30 days.展开更多
Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influenc...Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.展开更多
AIM: To investigate dose-dependent effects of N-methylD-aspartate(NMDA) on retinal and optic nerve morphology in rats.METHODS: Sprague Dawley rats, 180-250 g in weight were divided into four groups. Groups 1, 2, 3 and...AIM: To investigate dose-dependent effects of N-methylD-aspartate(NMDA) on retinal and optic nerve morphology in rats.METHODS: Sprague Dawley rats, 180-250 g in weight were divided into four groups. Groups 1, 2, 3 and 4 were intravitreally administered with vehicle and NMDA at the doses 80, 160 and 320 nmol respectively. Seven days after injection, rats were euthanized, and their eyes were taken for optic nerve toluidine blue and retinal hematoxylin and eosin stainings. The TUNEL assay was done for detecting apoptotic cells.RESULTS: All groups treated with NMDA showed significantly reduced ganglion cell layer(GCL) thickness within inner retina, as compared to control group. Group NMDA 160 nmol showed a significantly greater GCL thickness than the group NMDA 320 nmol. Administration of NMDA also resulted in a dose-dependent decrease in the number of nuclei both per 100 μm GCL length and per 100 μm2 of GCL. Intravitreal NMDA injection caused dosedependent damage to the optic nerve. The degeneration of nerve fibres with increased clearing of cytoplasm was observed more prominently as the NMDA dose increased. In accordance with the results of retinal morphometry analysis and optic nerve grading, TUNEL staining demonstrated NMDA-induced excitotoxic retinal injury in a dose-dependent manner.CONCLUSION: Our results demonstrate dose-dependent effects of NMDA on retinal and optic nerve morphology in rats that may be attributed to differences in the severity of excitotoxicity and oxidative stress. Our results also suggest that care should be taken while making dose selections experimentally so that the choice might best uphold study objectives.展开更多
The present study determined the thyroid hormone interference of tetrabromobisphenol A (TBBPA) in Sprague-Dawley (SD) rats, and the derived-reference dose (RfD) of different endpoint effects on mammals based on ...The present study determined the thyroid hormone interference of tetrabromobisphenol A (TBBPA) in Sprague-Dawley (SD) rats, and the derived-reference dose (RfD) of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day. Therefore, RfDs were derived from different critical effects. In summary, RfD for mammals in the present study was found to be 0.6 mg/kg per day.展开更多
In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiat...In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.展开更多
The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors (nMOSFETs) is investigated. Experimental results show that hot-carrier degradati...The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors (nMOSFETs) is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation (STI). The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect.展开更多
BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in ...BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in CC have not yet been elucidated.AIM To investigate the role and mechanism of a novel miR-490-3p/hnRNPA1-b/PKM2 axis in enhancing the Warburg effect and promoting CC cell proliferation through the PI3K/AKT pathway.METHODS Paraffin-embedded pathological sections from 220 CC patients were collected and subjected to immunohistochemical analysis to determine the expression of hnRNPA1-b.The relationship between the expression values and the clinicopathological features of the patients was investigated.Differences in mRNA expression were analyzed using quantitative real-time polymerase chain reaction,while differences in protein expression were analyzed using western blot.Cell proliferation was evaluated using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays,and cell cycle and apoptosis were detected using flow cytometric assays.The targeted binding of miR-490-3p to hnRNPA1-b was validated using a dual luciferase reporter assay.The Warburg effect was evaluated by glucose uptake and lactic acid production assays.RESULTS The expression of hnRNPA1-b was significantly increased in CC tissues and cells compared to normal controls(P<0.05).Immunohistochemical results demonstrated significant variations in the expression of the hnRNPA1-b antigen in different stages of CC,including stage I,II-III,and IV.Furthermore,the clinicopathologic characterization revealed a significant correlation between hnRNPA1-b expression and clinical stage as well as T classification.HnRNPA1-b was found to enhance the Warburg effect through the PI3K/AKT pathway,thereby promoting proliferation of HCT116 and SW620 cells.However,the proliferation of HCT116 and SW620 cells was inhibited when miR-490-3p targeted and bound to hnRNPA1-b,effectively blocking the Warburg effect.CONCLUSION These findings suggest that the novel miR-490-3p/hnRNPA1-b/PKM2 axis could provide a new strategy for the diagnosis and treatment of CC.展开更多
Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reper...Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reperfusion injury(MIRI),and the principle of electroacupuncture(EA)preconditioning is comparable to that of myocardial ischemic preconditioning adaption.Our earlier research demonstrated that EA pretreatment inhibits the expression of calmodulin-dependent protein kinase IIδ(CaMKIIδ),sodium/calcium exchanger 1(NCX1),and cyclophilin D,hence providing protection against MIRI.However,the exact mechanism is still unknown.The expression of NCX1 mRNA is directly regulated by microRNA-214(miR-214).Moreover,it suppresses the levels of CaMKIIδand cyclophilin D.Whether these variables contribute to EA preconditioning to improve MIRI needs to be investigated,though.This study aimed to preliminarily determine whether EA pretreatment ameliorates MIRI by modulating the miR-214-3p/NCX1 axis.Methods:We used a rat MIRI model to investigate the effect of EA pretreatment on MIRI and the expression of miR-214-3p.In addition,adenovirus injection inhibited miR-214-3p expression in the rat MIRI model,and the influence of EA pretreatment towards MIRI was observed in the context of blocked miR-214-3p expression.Both the myocardial histological abnormalities and the alterations in the ST segment of the rat electrocardiogram were analyzed.NCX1 mRNA,cyclophilin D,and CaMKIIδexpression levels were also analyzed.Results:EA pretreatment improved MIRI.In rats with MIRI,EA administration increased miR-214-3p expression while decreasing NCX1 mRNA,cyclophilin D,and CaMKIIδproteins in cardiac tissues.The beneficial effect of EA pretreatment against MIRI was reversed,coupled with elevated levels of NCX1 mRNA,cyclophilin D,and CaMKIIδprotein expression,when an adenovirus injection disrupted the expression of miR-214-3p.Conclusions:Our findings preliminarily show that EA pretreatment inhibits the expression of NCX1 mRNA,cyclophilin D,and CaMKIIδproteins via miR-214-3p,hence exerting MIRI protection.展开更多
Because of the discrete charge storage mechanism, charge trapping memory(CTM) technique is a good candidate for aerospace and military missions. The total ionization dose(TID) effects on CTM cells with Al2O3/HfO2/...Because of the discrete charge storage mechanism, charge trapping memory(CTM) technique is a good candidate for aerospace and military missions. The total ionization dose(TID) effects on CTM cells with Al2O3/HfO2/Al2O3(AHA) high-k gate stack structure under in-situ 10 keV x-rays are studied. The C-V characteristics at different radiation doses demonstrate that charge stored in the device continues to be leaked away during the irradiation,thereby inducing the shift of flat band voltage(V(fb)). The dc memory window shows insignificant changes, suggesting the existence of good P/E ability. Furthermore, the physical mechanisms of TID induced radiation damages in AHA-based CTM are analyzed.展开更多
In this study, a scintillation detector was developed to measure the space proton effective dose for astronauts based on the proton effective dose conversion coefficients provided by International Commission on Radiol...In this study, a scintillation detector was developed to measure the space proton effective dose for astronauts based on the proton effective dose conversion coefficients provided by International Commission on Radiological Protection Report No. 116. In the Monte Carlo N-Particle Transport Code X(version 2.6.0) simulation process, by modulating the depth and solid angle of truncated conical holes in an iron shell from lower-energy protons to higher-energy protons, the energy deposited in the scintillator by isotropic protons was nearly proportional to the corresponding effective dose, with a maximum relative deviation of 13.28% at thirteen energy points in the energy range of 10–400 MeV. Therefore, the detector can monitor proton effective dose indirectly in real time by measuring the deposited energy. We calibrated the photoelectric conversion efficiency of the detector at the cobalt source, tested the response of the detector in the energy range of 30–100 MeV in unidirectional proton field, and validated the simulation with the experimental results.展开更多
The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose ...The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.展开更多
The magnitude of radiation dose imparted to patients who underwent Head Computed Tomography examination in a large tertiary hospital in South-Southern Nigeria has been estimated. CT-ExPO dosimetry software was used to...The magnitude of radiation dose imparted to patients who underwent Head Computed Tomography examination in a large tertiary hospital in South-Southern Nigeria has been estimated. CT-ExPO dosimetry software was used to determine the effective and organ doses to the head region of 40 adult patients. Scanning parameters were retrieved from the CT monitor for both contrast-enhanced and non-contrast head CT examinations. The tube potential ranged from 100 kVp to 120 kVp, while the mAs ranged from 127 mAs to 202 mAs. The mean values of the volume Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) for the contrast-enhanced Head CT examination were 166.4 ± 39.6 mGy and 3568.6 ± 756.1 mGy·cm, respectively, while for the non-contrast examination they were 86.6 ± 30.4 mGy and 2102.3 ± 870.3 mGy·cm, respectively. The effective doses were higher for the contrast-enhanced study than for the non-contrast study by a factor of 1.6. Results were compared with the European Union reference doses and other published data and were found to be higher. Doses to the organs which comprise of brain, red bone marrow, thyroid and eye lens were also estimated. The high variation in the doses in this study may be due to differences in imaging protocols such as large range of mAs and scan lengths and also the algorithm of the scanner.展开更多
Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Fac...Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building: classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.展开更多
A low-dropout voltage regulator,LM2941,was irradiated by ^(60)Coγ-rays at various dose rates and biases for investigating the total dose and dose rate effects.The radiation responses show that the key electrical para...A low-dropout voltage regulator,LM2941,was irradiated by ^(60)Coγ-rays at various dose rates and biases for investigating the total dose and dose rate effects.The radiation responses show that the key electrical parameters, including its output and dropout voltage,and the maximum output current,are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias.The integrated circuits damage change with the dose rates and biases,and the dose-rate effects are relative to its electric field.展开更多
文摘Objective:To analyze the clinical effect of high-dose citrate in segmental extracorporeal anticoagulation for high-throughput hemodialysis.Methods:The subjects included in this study were admitted to the hospital for maintenance hemodialysis treatment from January 2021 to January 2023.All patients had a high risk of bleeding and received 4%trisodium citrate anticoagulant treatment,administered at a rate of 200 mL/h before and after the dialyzer.The anticoagulant effects achieved by the patients were observed and analyzed.Results:The total number of patients who received high-dose segmented citrate extracorporeal anticoagulation dialysis treatment was 50,with each patient undergoing 100 treatments.During the treatment,2 patients had to end the treatment early due to transmembrane pressure exceeding 30 mmHg and an increase in venous pressure exceeding 250 mmHg;the treatment times for these patients were 20 minutes and 200 minutes,respectively.The remaining patients successfully completed the 4-hour treatment.Blood pH and calcium ion concentration in the venous pot were monitored.It was observed that before dialysis,after 2 hours of dialysis,and at the end of dialysis,the blood pH of the patients remained within a relatively normal range.Although some patient levels changed after dialysis,they remained within the normal range.No adverse reactions(such as numbness of the limbs or convulsions)were observed during the anticoagulant treatment.Conclusion:Administering 4%trisodium citrate at a rate of 200 mL/h before and after the dialyzer achieves a good anticoagulant effect,maintains the patient’s blood gas levels within the normal range at the end of dialysis,and causes no adverse reactions.
基金supported by the National Natural Science Foundation of China(No.11705276)the West Light Foundation of the Chinese Academy of Sciences(No.CAS-LWC-2017-2)
文摘A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,from which the total ionizing dose(TID) and the synergistic damage mechanism of MRAM were analyzed.In addition,DC,AC,and functional parameters of the memory were tested under irradiation and annealing via a very large-scale integrated circuit test system.The radiation-sensitive parameters were obtained through analyzing the data.Because of the magnetic field applied on the MRAM while testing the synergistic effects,shallow trench isolation leakage and Frenkel–Poole emission due to synergistic effects were smaller than that of TID,and hence radiation damage of the synergistic effects was also lower.
基金supported by the Project of National Natural Science Foundation of China(Grant Nos.61376099,11235008,61434007)the Specialized Research Fund for the Doctoral Program of High Education(Grant No.20130203130002)
文摘This work researched the impact of total dose irradiation on the threshold voltage of N-type metal oxide semiconductor field effect transistors(nMOSFETs) in silicon-on-insulator(SOI) technology.Using the subthreshold separation technology,the factor causing the threshold voltage shift was divided into two parts:trapped oxide charges and interface states,the effects of which are presented under irradiation.Furthermore,by analyzing the data,the threshold voltage shows a negative shift at first and then turns to positive shift when irradiation dose is lower.Additionally,the influence of the dose rate effects on threshold voltage is discussed.The research results show that the threshold voltage shift is more significant in low dose rate conditions,even for a low dose of100 krad(Si).The degeneration value of threshold voltage is 23.4%and 58.0%for the front-gate and the back-gate at the low dose rate,respectively.
基金supported by the National Natural Science Foundation of China (Nos. 11690040 and 11690043)。
文摘Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific discovery approach.The total ionizing dose(TID)effects usually cause gain degradation of bipolar junction transistors(BJTs),leading to functional failures of bipolar integrated circuits.Currently,many experiments of TID effects on BJTs have been conducted at different laboratories worldwide,producing a large amount of experimental data which provides a wealth of information.However,it is difficult to utilize these data effectively.In this study,we proposed a new artificial neural network(ANN)approach to analyze the experimental data of TID effects on BJTs An ANN model was built and trained using data collected from different experiments.The results indicate that the proposed ANN model has advantages in capturing nonlinear correlations and predicting the data.The trained ANN model suggests that the TID hardness of a BJT tends to increase with base current I.A possible cause for this finding was analyzed and confirmed through irradiation experiments.
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The influence of combined total ionization dose(TID)and radiated electromagnetic interference(EMI)in a commercial analog-to-digital converter(ADC)was studied.The degradation of the direct-current response,the static parameters,and the dynamic parameters caused by the TID and EMI separately and synergistically is presented.The experimental results demonstrate that the increase in TID intensifies data error and the signal-tonoise ratio(SNR)degradation caused by radiated EMI.The cumulative distribution function of EMI failure with respect to data error and SNR with different TIDs was extracted.The decreasing trend of the threshold was acquired with a small sample size of five for each TID group.The result indicates that the ADC is more sensitive in a compound radiation environment.
基金financially supported by the Science Innovation Project of Beijing Forestry University (No. 101305)the 985 Innovation Platform, China
文摘In order to prevent severe pollution by de-icing salt on greenery along urban roads, a half lethal dose (LD_50)for a plant population was confirmed through stress simulation of chloride de-icing salt on Euonymus japonicus, with an ianalysis of physiological changes, statistics on mortality rate on plant populations and mathematic modeling during a 30- day subacute toxicity test. The results indicate that a significant positive correlation in the early stages and a significant negative correlation in the later stages were observed between the amount of chlorophyll a and b in plants and a cumulative dose of de-icing salt. The amounts of free proline in plants and the dose of de-icing salt were positively correlated Over the entire period. No significant correlation in the initial stage, but a significant negative correlation in later stages was observed between the soluble protein and the dose of de-icing salt. LDs0 of this chloride agent on E. japonicus is 5 kg.(L·m2)-1 over 30 days.
文摘Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.
基金Supported by Universiti Teknologi MARA [No.600-IRMI/MYRA5/3/BESTARI (004/2017) No.600IRMI/DANA5/3/LESTARI (0076/2016) No.600-IRMI/ My RA5/3/LESTARI (0088/2016)]
文摘AIM: To investigate dose-dependent effects of N-methylD-aspartate(NMDA) on retinal and optic nerve morphology in rats.METHODS: Sprague Dawley rats, 180-250 g in weight were divided into four groups. Groups 1, 2, 3 and 4 were intravitreally administered with vehicle and NMDA at the doses 80, 160 and 320 nmol respectively. Seven days after injection, rats were euthanized, and their eyes were taken for optic nerve toluidine blue and retinal hematoxylin and eosin stainings. The TUNEL assay was done for detecting apoptotic cells.RESULTS: All groups treated with NMDA showed significantly reduced ganglion cell layer(GCL) thickness within inner retina, as compared to control group. Group NMDA 160 nmol showed a significantly greater GCL thickness than the group NMDA 320 nmol. Administration of NMDA also resulted in a dose-dependent decrease in the number of nuclei both per 100 μm GCL length and per 100 μm2 of GCL. Intravitreal NMDA injection caused dosedependent damage to the optic nerve. The degeneration of nerve fibres with increased clearing of cytoplasm was observed more prominently as the NMDA dose increased. In accordance with the results of retinal morphometry analysis and optic nerve grading, TUNEL staining demonstrated NMDA-induced excitotoxic retinal injury in a dose-dependent manner.CONCLUSION: Our results demonstrate dose-dependent effects of NMDA on retinal and optic nerve morphology in rats that may be attributed to differences in the severity of excitotoxicity and oxidative stress. Our results also suggest that care should be taken while making dose selections experimentally so that the choice might best uphold study objectives.
基金supported by the National Natural Science Foundation of China(No.21377045)Joint Innovation Funding of Production and Research-a Prospective Joint Research Project(BY2015027-05)
文摘The present study determined the thyroid hormone interference of tetrabromobisphenol A (TBBPA) in Sprague-Dawley (SD) rats, and the derived-reference dose (RfD) of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day. Therefore, RfDs were derived from different critical effects. In summary, RfD for mammals in the present study was found to be 0.6 mg/kg per day.
文摘In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11475255,U1532261 and 11505282
文摘The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors (nMOSFETs) is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation (STI). The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect.
基金Supported by the National Natural Science Foundation of China,No.82160405Jiangxi Provincial Natural Science Foundation,No.20232BAB206131,No.20212ACB206016,and No.20224BAB206114+1 种基金Jiangxi Provincial Health Commission Project,No.202310887the Development Fund of Jiangxi Cancer Hospital,No.2021J10.
文摘BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in CC have not yet been elucidated.AIM To investigate the role and mechanism of a novel miR-490-3p/hnRNPA1-b/PKM2 axis in enhancing the Warburg effect and promoting CC cell proliferation through the PI3K/AKT pathway.METHODS Paraffin-embedded pathological sections from 220 CC patients were collected and subjected to immunohistochemical analysis to determine the expression of hnRNPA1-b.The relationship between the expression values and the clinicopathological features of the patients was investigated.Differences in mRNA expression were analyzed using quantitative real-time polymerase chain reaction,while differences in protein expression were analyzed using western blot.Cell proliferation was evaluated using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays,and cell cycle and apoptosis were detected using flow cytometric assays.The targeted binding of miR-490-3p to hnRNPA1-b was validated using a dual luciferase reporter assay.The Warburg effect was evaluated by glucose uptake and lactic acid production assays.RESULTS The expression of hnRNPA1-b was significantly increased in CC tissues and cells compared to normal controls(P<0.05).Immunohistochemical results demonstrated significant variations in the expression of the hnRNPA1-b antigen in different stages of CC,including stage I,II-III,and IV.Furthermore,the clinicopathologic characterization revealed a significant correlation between hnRNPA1-b expression and clinical stage as well as T classification.HnRNPA1-b was found to enhance the Warburg effect through the PI3K/AKT pathway,thereby promoting proliferation of HCT116 and SW620 cells.However,the proliferation of HCT116 and SW620 cells was inhibited when miR-490-3p targeted and bound to hnRNPA1-b,effectively blocking the Warburg effect.CONCLUSION These findings suggest that the novel miR-490-3p/hnRNPA1-b/PKM2 axis could provide a new strategy for the diagnosis and treatment of CC.
基金supported fiancially by the Natural Science Foundation of Inner Mongolia Autonomous Region in China(Grant No.2018MS08043)Inner Mongolia Autonomous Region Scientific and Technological Achievements Transformation Guidance Project in China(2020PT0030).
文摘Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reperfusion injury(MIRI),and the principle of electroacupuncture(EA)preconditioning is comparable to that of myocardial ischemic preconditioning adaption.Our earlier research demonstrated that EA pretreatment inhibits the expression of calmodulin-dependent protein kinase IIδ(CaMKIIδ),sodium/calcium exchanger 1(NCX1),and cyclophilin D,hence providing protection against MIRI.However,the exact mechanism is still unknown.The expression of NCX1 mRNA is directly regulated by microRNA-214(miR-214).Moreover,it suppresses the levels of CaMKIIδand cyclophilin D.Whether these variables contribute to EA preconditioning to improve MIRI needs to be investigated,though.This study aimed to preliminarily determine whether EA pretreatment ameliorates MIRI by modulating the miR-214-3p/NCX1 axis.Methods:We used a rat MIRI model to investigate the effect of EA pretreatment on MIRI and the expression of miR-214-3p.In addition,adenovirus injection inhibited miR-214-3p expression in the rat MIRI model,and the influence of EA pretreatment towards MIRI was observed in the context of blocked miR-214-3p expression.Both the myocardial histological abnormalities and the alterations in the ST segment of the rat electrocardiogram were analyzed.NCX1 mRNA,cyclophilin D,and CaMKIIδexpression levels were also analyzed.Results:EA pretreatment improved MIRI.In rats with MIRI,EA administration increased miR-214-3p expression while decreasing NCX1 mRNA,cyclophilin D,and CaMKIIδproteins in cardiac tissues.The beneficial effect of EA pretreatment against MIRI was reversed,coupled with elevated levels of NCX1 mRNA,cyclophilin D,and CaMKIIδprotein expression,when an adenovirus injection disrupted the expression of miR-214-3p.Conclusions:Our findings preliminarily show that EA pretreatment inhibits the expression of NCX1 mRNA,cyclophilin D,and CaMKIIδproteins via miR-214-3p,hence exerting MIRI protection.
基金Supported by the National Natural Science Foundation of China under Grant No 616340084the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2014101+1 种基金the International Cooperation Project of Chinese Academy of Sciencesthe Austrian-Chinese Cooperative R&D Projects under Grant No 172511KYSB20150006
文摘Because of the discrete charge storage mechanism, charge trapping memory(CTM) technique is a good candidate for aerospace and military missions. The total ionization dose(TID) effects on CTM cells with Al2O3/HfO2/Al2O3(AHA) high-k gate stack structure under in-situ 10 keV x-rays are studied. The C-V characteristics at different radiation doses demonstrate that charge stored in the device continues to be leaked away during the irradiation,thereby inducing the shift of flat band voltage(V(fb)). The dc memory window shows insignificant changes, suggesting the existence of good P/E ability. Furthermore, the physical mechanisms of TID induced radiation damages in AHA-based CTM are analyzed.
基金supported by the National Natural Science Foundation of China(No.11305127)the State Key Lab of Intense Pulsed Radiation Simulation and Effect Basic Research Foundation(No.SKLIPR1216)
文摘In this study, a scintillation detector was developed to measure the space proton effective dose for astronauts based on the proton effective dose conversion coefficients provided by International Commission on Radiological Protection Report No. 116. In the Monte Carlo N-Particle Transport Code X(version 2.6.0) simulation process, by modulating the depth and solid angle of truncated conical holes in an iron shell from lower-energy protons to higher-energy protons, the energy deposited in the scintillator by isotropic protons was nearly proportional to the corresponding effective dose, with a maximum relative deviation of 13.28% at thirteen energy points in the energy range of 10–400 MeV. Therefore, the detector can monitor proton effective dose indirectly in real time by measuring the deposited energy. We calibrated the photoelectric conversion efficiency of the detector at the cobalt source, tested the response of the detector in the energy range of 30–100 MeV in unidirectional proton field, and validated the simulation with the experimental results.
文摘The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.
文摘The magnitude of radiation dose imparted to patients who underwent Head Computed Tomography examination in a large tertiary hospital in South-Southern Nigeria has been estimated. CT-ExPO dosimetry software was used to determine the effective and organ doses to the head region of 40 adult patients. Scanning parameters were retrieved from the CT monitor for both contrast-enhanced and non-contrast head CT examinations. The tube potential ranged from 100 kVp to 120 kVp, while the mAs ranged from 127 mAs to 202 mAs. The mean values of the volume Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) for the contrast-enhanced Head CT examination were 166.4 ± 39.6 mGy and 3568.6 ± 756.1 mGy·cm, respectively, while for the non-contrast examination they were 86.6 ± 30.4 mGy and 2102.3 ± 870.3 mGy·cm, respectively. The effective doses were higher for the contrast-enhanced study than for the non-contrast study by a factor of 1.6. Results were compared with the European Union reference doses and other published data and were found to be higher. Doses to the organs which comprise of brain, red bone marrow, thyroid and eye lens were also estimated. The high variation in the doses in this study may be due to differences in imaging protocols such as large range of mAs and scan lengths and also the algorithm of the scanner.
基金supported by a grant of The Scientific and Technical Research Council of Turkey(TUBiTAK)
文摘Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building: classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.
文摘A low-dropout voltage regulator,LM2941,was irradiated by ^(60)Coγ-rays at various dose rates and biases for investigating the total dose and dose rate effects.The radiation responses show that the key electrical parameters, including its output and dropout voltage,and the maximum output current,are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias.The integrated circuits damage change with the dose rates and biases,and the dose-rate effects are relative to its electric field.