Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric aci...Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric acid.Next,ATP borate ester pretreatments were assessed to study their effects on cell sensitization from exposure to thermal neutron irradiation emitted by a nuclear reactor.Using cell viability assays(CCK8),survival rates of A549 cells pretreated with or without boroncontaining agents,including ATP borate ester and 4-dihydroxyborylphenylalanine(BPA),were measured.One week after feeding an ATP borate ester solution to tumorbearing nude mice,elemental B content values of tumor muscle and blood were measured using inductively coupled plasma mass spectrometry(ICP-MS).Meanwhile,other tumor tissue samples were placed in a culture medium,subjected to a 3-min neutron irradiation exposure,and then fixed in formalin 24 h later for the terminaldeoxynucleotidyl transferase(TDT)-mediated d UTP nick end labeling(TUNEL)immunohistochemical staining analysis.Results showed that A549 cell irradiation sensitization(irradiation dose of 0.33 Gy)varied with pretreatment.Sensitization values of the ATP borate ester pretreatment group were 1.3–14.1 with boron agent concentrations of 0.3–4.5 mM.Within 1.1–3.4 mM,ATP borate ester showed significantly higher sensitization values than BPA.Meanwhile,TUNEL results demonstrated that apoptosis rates of tumor tissue cells exposed to irradiation after ATP borate ester pretreatment significantly exceeded the corresponding rates for BPA-pretreated cells.In animal experiments,although the distribution ratio of ATP borate ester(tumor tissue/normal muscle,T/N)of 1.2 was not significantly different compared with that of BPA(1.3),the total ATP borate ester concentration in the tumor tissue(0.79±0.05μg/g)significantly exceeded that of BPA(0.58±0.05μg/g).Thus,compared with BPA,the greater enrichment of ATP borate ester in tumor tissues permits preferential targeting toward tumor cells for radiation sensitization.Therefore,ATP borate ester is superior to BPA for use in boron neutron capture therapy.展开更多
Rats of both sexes were fed on a basal feed containing 1% refined konjac meal (RKM) for 18 months and the effects of RKM on the cell aging were observed. A comparable group fed on the basic feed was used as the contro...Rats of both sexes were fed on a basal feed containing 1% refined konjac meal (RKM) for 18 months and the effects of RKM on the cell aging were observed. A comparable group fed on the basic feed was used as the control. Results obtained demonstrate that the long-term feeding of RKM to rats can delay the course of cell aging of the gliocyte, cadiomyocyte, and the endothelial cell of the large and medium arteriases, hence it is likely to delay the occurrence of arteriosclerosis and improve the functions of the brain, heart and vascular system.展开更多
Objective Since most reports on bystander effect have been only concerned with radiation-induced damage, the present paper aimed at disclosing whether low dose radiation could induce a stimulatory or beneficial bystan...Objective Since most reports on bystander effect have been only concerned with radiation-induced damage, the present paper aimed at disclosing whether low dose radiation could induce a stimulatory or beneficial bystander effect. Methods A co-culture system containing irradiated antigen presenting cells (J774A.1) and unirradiated T lymphocytes (EL-4) was established to observe the effect of J774A.1 cells exposed to both low and high doses of X-rays on the unirradiated EL-4 cells. Incorporation of 3H-TdR was used to assess the proliferation of the EL-4 cells, expression of CD80/86 and CD48 on J774A.1 cells was measured with immunohistochemistry and flow cytometry, respectively. NO release from J774A.1 cells was estimated with nitrate reduction method. Results Low dose-irradiated J774A.1 cells could stimulate the proliferation of the unirradiated EL-4 cells while the high dose-irradiated J774A.1 cells exerted an inhibitory effect on the proliferation of the unirradiated EL-4 cells. Preliminary mechanistic studies illustrated that the differential changes in CD48 expression and NO production by the irradiated J774A.1 cells after high and low dose radiation might be important factors underlying the differential bystander effect elicited by different doses of radiation. Conclusion Stimulatory bystander effect can be induced in immune cells by low dose radiation.展开更多
The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shun...The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed.展开更多
There is increasing evidence showing a close relationship between human radiation sensitivity and age-related health effects including cancer.Individuals exposed to ionizing radiation(IR)are the most radiosensitive at...There is increasing evidence showing a close relationship between human radiation sensitivity and age-related health effects including cancer.Individuals exposed to ionizing radiation(IR)are the most radiosensitive at early ages,and decrease in radiation sensitivity until maturity,but increase again at older ages,as measured with incidence of carcinogenic events.This article reviews the historical and current status of aging and age-related health effects induced by IR,with results obtained from epidemiological,animal and in vitro studies over the last 20 years.Mechanistic studies underlying these radiation-induced effects are summarized in terms of DNA damage and genomic instability,telomere erosion,oxidative stress and inflammation,as well as radiation-associated cellular senescence and epigenetic alterations.Since individual radiosensitivity changes with age and the life expectancy of population rises steadily,there is a pressing need for a better understanding of the aging-radiation exposure association so as to improve radiation protection in clinical practice.展开更多
The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylate...The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylated flavanones with obvious anti-proliferative effects in lung cancer A549 cells. In the present study, a new C-geranylated flavone, paucatalinone C(1) and five known C-geranylated flavanones(2-6) were isolated. In addition, a total of 34 C-geranylated flavonoids were detected by HPLC-DAD-ESI-MS/MS coupling techniques from the CH_2Cl_2 extract of P. catalpifolia. Futhermore, anti-aging effects of isolated compounds were evaluated in vitro with premature senescent 2BS cells induced by H_2O_2. Phytochemical results indicated that P. catalpifolia was a natural resource of abundant C-geranylated flavonoids. Diplacone(3) and paucatalinone A(5) were the potent anti-aging agents in the premature senescent 2BS cells induced by H_2O_2 and the C-geranyl substituent may be an important factor because of its lipophilic character.展开更多
Diesel exhaust (Diesel exhaust particles, DEPs, and their extracts, DPE) and ultraviolet A are two ubiquitous environmental factors that have been identified as essential risk factors
There are few efficient therapeutic approaches to hepatocarcinoma.Chen et al1 developed iodine （131I） metuximab injection （Licartin）,a novel 131I-labeled HAb18G/CD147-specific monoclonal antibody Fab＇2 fragment.H...There are few efficient therapeutic approaches to hepatocarcinoma.Chen et al1 developed iodine （131I） metuximab injection （Licartin）,a novel 131I-labeled HAb18G/CD147-specific monoclonal antibody Fab＇2 fragment.HAb18G/CD147 is a hepatocellular carcinoma-associated antigen.But their results have no obvious improvements in survival rate of patients with hepatocarcinoma.Keywords：radiation effects; promoter regions, genetic lentivirus; cytosine deaminase; fluorocytosine; HepG2 cells展开更多
INTRODUCTIONTo date ,the major therapy for rectal carcinoma is extensive abdomino-perineal resection[1]. Unfortunately ,after resection of rectal carcinoma ,many patients still die of blood-borne metastases ,usually i...INTRODUCTIONTo date ,the major therapy for rectal carcinoma is extensive abdomino-perineal resection[1]. Unfortunately ,after resection of rectal carcinoma ,many patients still die of blood-borne metastases ,usually in the liver or lungs ,or local prlvic recurrence[2,3],which is the major cause of morbidity and mortality in patients with rectal carcinoma .Pre-or postoperative radiotherapy can reduce the incidence of local rdcurrence[4-7].展开更多
The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe（In）/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In...The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe（In）/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In to make a thin film on a p-Si single crystal wafer with a thickness of 100μm and a resistivity of～1.5Ω·cm at a temperature of 473 K.The short-circuit current density（jsc）,open-circuit voltage（Voc）,fill factor（ff） and conversion efficiency（η） under 100 mW/cm^2（AMI） intensity,are 20 mA/cm^2,0.49 V,0.71 and 6%respectively. The cells were exposed to different electron doses（electron beam accelerator of energy 1.5 MeV,and beam intensity 25 mA）.The cell performance parameters are measured and discussed before and after gamma and electron beam irradiation.展开更多
Investigating the thermal transport properties of materials is of great importance in the field of earth science and for the development of materials under extremely high temperatures and pressures.However,it is an en...Investigating the thermal transport properties of materials is of great importance in the field of earth science and for the development of materials under extremely high temperatures and pressures.However,it is an enormous challenge to characterize the thermal and physical properties of materials using the diamond anvil cell(DAC)platform.In the present study,a steady-state method is used with a DAC and a combination of thermocouple temperature measurement and numerical analysis is performed to calculate the thermal conductivity of the material.To this end,temperature distributions in the DAC under high pressure are analyzed.We propose a three-dimensional radiative-conductive coupled heat transfer model to simulate the temperature field in the main components of the DAC and calculate in situ thermal conductivity under high-temperature and high-pressure conditions.The proposed model is based on the finite volume method.The obtained results show that heat radiation has a great impact on the temperature field of the DAC,so that ignoring the radiation effect leads to large errors in calculating the heat transport properties of materials.Furthermore,the feasibility of studying the thermal conductivity of different materials is discussed through a numerical model combined with locally measured temperature in the DAC.This article is expected to become a reference for accurate measurement of in situ thermal conductivity in DACs at high-temperature and high-pressure conditions.展开更多
With the critical charge reduced to generate a single event effect （SEE） and high working frequency for a nanometer integrated circuit, the single event effect （SET） becomes increasingly serious for high performan...With the critical charge reduced to generate a single event effect （SEE） and high working frequency for a nanometer integrated circuit, the single event effect （SET） becomes increasingly serious for high performance SOC and DSP chips. To analyze the radiation-hardened method of SET for the nanometer integrated circuit, the n＋ guard ring and p＋ guard ring have been adopted in the layout for a 65 nm commercial radiation-hardened standard cell library. The weakest driving capacity inverter cell was used to evaluate the single event transient （SET） pulse-width distribution. We employed a dual-lane measurement circuit to get more accurate SET＇s pulse- width. Six kinds of ions, which provide LETs of 12.5, 22.5, 32.5, 42, 63, and 79.5 MeV-cm2/mg, respectively, have been utilized to irradiate the SET test circuit in the Beijing Tandem Accelerator Nuclear Physics National Laboratory. The testing results reveal that the pulse-width of most SETs is shorter than 400 ps in the range of LETefr from 12.5 MeV.cm2/mg to 79.5 MeV-cm2/mg and the pulse-width presents saturation tendency when the effective linear energy transfer （LETeff value is larger than 40 MeV-cm2/mg. The test results also show that the hardened commercial standard cell＇s pulse-width concentrates on 33 to 264 ps, which decreases by 40% compared to the pulse-width of the 65 nm commercial unhardened standard cell.展开更多
Titanium dioxide nanoparticles (TiO2 NPs) are subjected to various transformation processes (chemical,physical and biological processes) in the environment,potentially affecting their bioavailability and toxic propert...Titanium dioxide nanoparticles (TiO2 NPs) are subjected to various transformation processes (chemical,physical and biological processes) in the environment,potentially affecting their bioavailability and toxic properties.However,the size variation of TiO2 NPs during aging process and subsequent effects in mammalian cells are largely unknown.The aim of this study was to illustrate the adverse effects of TiO2 NPs in different sizes (5,15 and <100 nm) during aging process on human-hamster hybrid (AL) cells.There was an aging-time dependent enhancement of average hydrodynamic size in TiO2 NPs stock suspensions.The cytotoxicity of fresh TiO2 NPs increased in a size-dependent manner;in contrast,their genotoxicity decreased with the increasing sizes of NPs.No significant toxicity difference was observed in cells exposed to either fresh or 60 day-aged TiO2 NPs.Both Fresh and aged TiO2 NPs efficiently induced mitochondrial dysfunction and activated Caspase-3/7 in a size-dependent manner.Using mitochondrial-DNA deficient (ρ°) AL cells,we further discovered that mitochondrial dysfunction made significant contribution to the size-dependent toxicity induced by TiO2 NPs during the aging process.Taken together,our data indicated that TiO2 NPs could significantly induced the cytotoxicity and genotoxicity in an aging time-independent and size-dependent manner,which were triggered by mitochondrial dysfunction.Our study suggested the necessity to include size as an additional parameter for the cautious monitoring of TiO2 NPs disposal before entering the environment.展开更多
基金supported by the project,‘‘Research on the targeted treatment of malignant tumors with Base 20180199 New Transmembrane Antibody’’(No.JCYJ20180507182217748)the National Natural Science Foundation of China(No.11375117)
文摘Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric acid.Next,ATP borate ester pretreatments were assessed to study their effects on cell sensitization from exposure to thermal neutron irradiation emitted by a nuclear reactor.Using cell viability assays(CCK8),survival rates of A549 cells pretreated with or without boroncontaining agents,including ATP borate ester and 4-dihydroxyborylphenylalanine(BPA),were measured.One week after feeding an ATP borate ester solution to tumorbearing nude mice,elemental B content values of tumor muscle and blood were measured using inductively coupled plasma mass spectrometry(ICP-MS).Meanwhile,other tumor tissue samples were placed in a culture medium,subjected to a 3-min neutron irradiation exposure,and then fixed in formalin 24 h later for the terminaldeoxynucleotidyl transferase(TDT)-mediated d UTP nick end labeling(TUNEL)immunohistochemical staining analysis.Results showed that A549 cell irradiation sensitization(irradiation dose of 0.33 Gy)varied with pretreatment.Sensitization values of the ATP borate ester pretreatment group were 1.3–14.1 with boron agent concentrations of 0.3–4.5 mM.Within 1.1–3.4 mM,ATP borate ester showed significantly higher sensitization values than BPA.Meanwhile,TUNEL results demonstrated that apoptosis rates of tumor tissue cells exposed to irradiation after ATP borate ester pretreatment significantly exceeded the corresponding rates for BPA-pretreated cells.In animal experiments,although the distribution ratio of ATP borate ester(tumor tissue/normal muscle,T/N)of 1.2 was not significantly different compared with that of BPA(1.3),the total ATP borate ester concentration in the tumor tissue(0.79±0.05μg/g)significantly exceeded that of BPA(0.58±0.05μg/g).Thus,compared with BPA,the greater enrichment of ATP borate ester in tumor tissues permits preferential targeting toward tumor cells for radiation sensitization.Therefore,ATP borate ester is superior to BPA for use in boron neutron capture therapy.
文摘Rats of both sexes were fed on a basal feed containing 1% refined konjac meal (RKM) for 18 months and the effects of RKM on the cell aging were observed. A comparable group fed on the basic feed was used as the control. Results obtained demonstrate that the long-term feeding of RKM to rats can delay the course of cell aging of the gliocyte, cadiomyocyte, and the endothelial cell of the large and medium arteriases, hence it is likely to delay the occurrence of arteriosclerosis and improve the functions of the brain, heart and vascular system.
基金This work was supported by grants from NSFC (No. 39270207, No. 39570188).
文摘Objective Since most reports on bystander effect have been only concerned with radiation-induced damage, the present paper aimed at disclosing whether low dose radiation could induce a stimulatory or beneficial bystander effect. Methods A co-culture system containing irradiated antigen presenting cells (J774A.1) and unirradiated T lymphocytes (EL-4) was established to observe the effect of J774A.1 cells exposed to both low and high doses of X-rays on the unirradiated EL-4 cells. Incorporation of 3H-TdR was used to assess the proliferation of the EL-4 cells, expression of CD80/86 and CD48 on J774A.1 cells was measured with immunohistochemistry and flow cytometry, respectively. NO release from J774A.1 cells was estimated with nitrate reduction method. Results Low dose-irradiated J774A.1 cells could stimulate the proliferation of the unirradiated EL-4 cells while the high dose-irradiated J774A.1 cells exerted an inhibitory effect on the proliferation of the unirradiated EL-4 cells. Preliminary mechanistic studies illustrated that the differential changes in CD48 expression and NO production by the irradiated J774A.1 cells after high and low dose radiation might be important factors underlying the differential bystander effect elicited by different doses of radiation. Conclusion Stimulatory bystander effect can be induced in immune cells by low dose radiation.
文摘The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed.
基金This work was partly supported by the State Key Laboratory of Radiation Medicine and Protection,and the Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases,Soochow University,China.The authors would like to thank Professor Zhifang Chai of School of Radiation Medicine and Protection,Soochow University,for his critical review and informative advice for this manuscript.
文摘There is increasing evidence showing a close relationship between human radiation sensitivity and age-related health effects including cancer.Individuals exposed to ionizing radiation(IR)are the most radiosensitive at early ages,and decrease in radiation sensitivity until maturity,but increase again at older ages,as measured with incidence of carcinogenic events.This article reviews the historical and current status of aging and age-related health effects induced by IR,with results obtained from epidemiological,animal and in vitro studies over the last 20 years.Mechanistic studies underlying these radiation-induced effects are summarized in terms of DNA damage and genomic instability,telomere erosion,oxidative stress and inflammation,as well as radiation-associated cellular senescence and epigenetic alterations.Since individual radiosensitivity changes with age and the life expectancy of population rises steadily,there is a pressing need for a better understanding of the aging-radiation exposure association so as to improve radiation protection in clinical practice.
基金financially supported by the Natural Science Foundation of Shandong Academy of Medical Sciences(No.2015-08)the Innovation Project of Shandong Academy of Medical Sciences and the Natural Science Open Foundation of State Key Laboratory of Bioactive Substance and Function of Natural Medicines(No.GTZK201503)
文摘The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylated flavanones with obvious anti-proliferative effects in lung cancer A549 cells. In the present study, a new C-geranylated flavone, paucatalinone C(1) and five known C-geranylated flavanones(2-6) were isolated. In addition, a total of 34 C-geranylated flavonoids were detected by HPLC-DAD-ESI-MS/MS coupling techniques from the CH_2Cl_2 extract of P. catalpifolia. Futhermore, anti-aging effects of isolated compounds were evaluated in vitro with premature senescent 2BS cells induced by H_2O_2. Phytochemical results indicated that P. catalpifolia was a natural resource of abundant C-geranylated flavonoids. Diplacone(3) and paucatalinone A(5) were the potent anti-aging agents in the premature senescent 2BS cells induced by H_2O_2 and the C-geranyl substituent may be an important factor because of its lipophilic character.
文摘Diesel exhaust (Diesel exhaust particles, DEPs, and their extracts, DPE) and ultraviolet A are two ubiquitous environmental factors that have been identified as essential risk factors
基金This work was supported by grants from Beijing Natural Science Foundation （No.7083115 and 7112129）,and Key Laboratory of Nuclear Medicine,Ministry of Health,Jiangsu Key Laboratory of Molecular Nuclear Medicine,Jiangsu Institute of Nuclear Medicine （No.KF201101）.
文摘There are few efficient therapeutic approaches to hepatocarcinoma.Chen et al1 developed iodine （131I） metuximab injection （Licartin）,a novel 131I-labeled HAb18G/CD147-specific monoclonal antibody Fab＇2 fragment.HAb18G/CD147 is a hepatocellular carcinoma-associated antigen.But their results have no obvious improvements in survival rate of patients with hepatocarcinoma.Keywords：radiation effects; promoter regions, genetic lentivirus; cytosine deaminase; fluorocytosine; HepG2 cells
基金Supported by the National Natural-Scientific Foundation,No.39500043
文摘INTRODUCTIONTo date ,the major therapy for rectal carcinoma is extensive abdomino-perineal resection[1]. Unfortunately ,after resection of rectal carcinoma ,many patients still die of blood-borne metastases ,usually in the liver or lungs ,or local prlvic recurrence[2,3],which is the major cause of morbidity and mortality in patients with rectal carcinoma .Pre-or postoperative radiotherapy can reduce the incidence of local rdcurrence[4-7].
文摘The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe（In）/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In to make a thin film on a p-Si single crystal wafer with a thickness of 100μm and a resistivity of～1.5Ω·cm at a temperature of 473 K.The short-circuit current density（jsc）,open-circuit voltage（Voc）,fill factor（ff） and conversion efficiency（η） under 100 mW/cm^2（AMI） intensity,are 20 mA/cm^2,0.49 V,0.71 and 6%respectively. The cells were exposed to different electron doses（electron beam accelerator of energy 1.5 MeV,and beam intensity 25 mA）.The cell performance parameters are measured and discussed before and after gamma and electron beam irradiation.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFA0702700)the National Natural Science Foundation of China(Grant Nos.11674404 and 11774126)。
文摘Investigating the thermal transport properties of materials is of great importance in the field of earth science and for the development of materials under extremely high temperatures and pressures.However,it is an enormous challenge to characterize the thermal and physical properties of materials using the diamond anvil cell(DAC)platform.In the present study,a steady-state method is used with a DAC and a combination of thermocouple temperature measurement and numerical analysis is performed to calculate the thermal conductivity of the material.To this end,temperature distributions in the DAC under high pressure are analyzed.We propose a three-dimensional radiative-conductive coupled heat transfer model to simulate the temperature field in the main components of the DAC and calculate in situ thermal conductivity under high-temperature and high-pressure conditions.The proposed model is based on the finite volume method.The obtained results show that heat radiation has a great impact on the temperature field of the DAC,so that ignoring the radiation effect leads to large errors in calculating the heat transport properties of materials.Furthermore,the feasibility of studying the thermal conductivity of different materials is discussed through a numerical model combined with locally measured temperature in the DAC.This article is expected to become a reference for accurate measurement of in situ thermal conductivity in DACs at high-temperature and high-pressure conditions.
文摘With the critical charge reduced to generate a single event effect （SEE） and high working frequency for a nanometer integrated circuit, the single event effect （SET） becomes increasingly serious for high performance SOC and DSP chips. To analyze the radiation-hardened method of SET for the nanometer integrated circuit, the n＋ guard ring and p＋ guard ring have been adopted in the layout for a 65 nm commercial radiation-hardened standard cell library. The weakest driving capacity inverter cell was used to evaluate the single event transient （SET） pulse-width distribution. We employed a dual-lane measurement circuit to get more accurate SET＇s pulse- width. Six kinds of ions, which provide LETs of 12.5, 22.5, 32.5, 42, 63, and 79.5 MeV-cm2/mg, respectively, have been utilized to irradiate the SET test circuit in the Beijing Tandem Accelerator Nuclear Physics National Laboratory. The testing results reveal that the pulse-width of most SETs is shorter than 400 ps in the range of LETefr from 12.5 MeV.cm2/mg to 79.5 MeV-cm2/mg and the pulse-width presents saturation tendency when the effective linear energy transfer （LETeff value is larger than 40 MeV-cm2/mg. The test results also show that the hardened commercial standard cell＇s pulse-width concentrates on 33 to 264 ps, which decreases by 40% compared to the pulse-width of the 65 nm commercial unhardened standard cell.
基金supported by the Strategic Leading Science&Technology Program(B)(No.XDB14030502)the National Natural Science Foundation of China grants(Nos.21677147,91743106,21507002,21507136 and 21607157)+3 种基金the Major/Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology(No.2017FXZY005)the CASHIPS Director’s Fund(No.YZJJ201704)the China Postdoctoral Science Foundation(No.2016M600477)the Anhui Province Postdoctoral Science Foundation(No.2017B161)
文摘Titanium dioxide nanoparticles (TiO2 NPs) are subjected to various transformation processes (chemical,physical and biological processes) in the environment,potentially affecting their bioavailability and toxic properties.However,the size variation of TiO2 NPs during aging process and subsequent effects in mammalian cells are largely unknown.The aim of this study was to illustrate the adverse effects of TiO2 NPs in different sizes (5,15 and <100 nm) during aging process on human-hamster hybrid (AL) cells.There was an aging-time dependent enhancement of average hydrodynamic size in TiO2 NPs stock suspensions.The cytotoxicity of fresh TiO2 NPs increased in a size-dependent manner;in contrast,their genotoxicity decreased with the increasing sizes of NPs.No significant toxicity difference was observed in cells exposed to either fresh or 60 day-aged TiO2 NPs.Both Fresh and aged TiO2 NPs efficiently induced mitochondrial dysfunction and activated Caspase-3/7 in a size-dependent manner.Using mitochondrial-DNA deficient (ρ°) AL cells,we further discovered that mitochondrial dysfunction made significant contribution to the size-dependent toxicity induced by TiO2 NPs during the aging process.Taken together,our data indicated that TiO2 NPs could significantly induced the cytotoxicity and genotoxicity in an aging time-independent and size-dependent manner,which were triggered by mitochondrial dysfunction.Our study suggested the necessity to include size as an additional parameter for the cautious monitoring of TiO2 NPs disposal before entering the environment.
