Summary: The purpose of this study was to investigate the molecular mechanism by which miR-21 and its target genes mediate radiation resistance of glioblastoma cells. Real-time PCR was employed to detect miR-21 expre...Summary: The purpose of this study was to investigate the molecular mechanism by which miR-21 and its target genes mediate radiation resistance of glioblastoma cells. Real-time PCR was employed to detect miR-21 expression in normal brain tissues, glioblastoma tissues and glioblastoma cell lines (A172, T98G and U87MG). T98G cells were transfected with anti-miR-21 oligonucleotides, or plasmids con- taining PDCD4 or hMSH2 (PDCD4-pcDNA3 and hMSH2-pcDNA3). The survival curve was obtained to investigate the sensitivity of T98G cells to radiation. Cell apoptosis was measured by using the Cas- pase-3/7 kit and cell cycle by flow cytometry. Western blotting was performed to detect the expression of hMSH2 and PDCD4 in miR-21-inhibiting T98G cells. The results showed that miR-21 expression in glioblastoma cells and tissues was conversely associated with the radiation sensitivity. Over-expression of miR-21 resulted in radiation resistance, while knockdown of miR-21 led to higher sensitivity of glioblastma cells to radiation. After miR-21 knockdown, the apoptosis of T98G cells was significantly increased and the G2 phase arrest was more significant. In addition, miR-21 knockdown increased the expression of endogenous PDCD4 and hMSH2, which contributed to the apoptosis and G2 arrest of T98G cells. The findings suggested that miR-21 may mediate the resistance of glioblastoma cells against radiation via its target genes PDCD4 and hMSH2. MiR-21 and its target genes may be used as potential molecular targets for clinical radiotherapy sensitization in the future.展开更多
The radiation damage responses of ttuorinated and non-fluorinated lateral PNP transistors are studied with specially designed gated-controlled lateral PNP transistors that allow for the extraction of the oxide trapped...The radiation damage responses of ttuorinated and non-fluorinated lateral PNP transistors are studied with specially designed gated-controlled lateral PNP transistors that allow for the extraction of the oxide trapped charge (Not) and interface trap (Nit) densities. All the samples are exposed in the Co-60γ ray with the dose rate of 0.5 Gy(Si)/s. After the irradiation, the buildup of Not and Nit of the samples with total dose is investigated by the gate sweep test technique. The results show that the radiation resistance of fluorinated lateral PNP transistors is significantly enhanced compared with the non-fluorinated ones.展开更多
Effects of Nb_(2)O_(5)dopant on the radiation response of barium gallo-germanate(BGG)glass are studied mainly by electron paramagnetic resonance and absorption spectroscopy.Owing to the Nb^(5+)$Nb^(3+)interconversion ...Effects of Nb_(2)O_(5)dopant on the radiation response of barium gallo-germanate(BGG)glass are studied mainly by electron paramagnetic resonance and absorption spectroscopy.Owing to the Nb^(5+)$Nb^(3+)interconversion in doped samples,formations of Ge-related non-bridging oxygen hole center and Ge-related electron center defects after g-ray irradiation are inhibited.Thereby,Nb_(2)O_(5)dopant can enhance radiation resistance of BGG glass,and 1.0%Nb2O5 concentration is the best.展开更多
The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR (infrared) spectra of initial and irradiated samples of tar fractions of bituminous oil are ...The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR (infrared) spectra of initial and irradiated samples of tar fractions of bituminous oil are compared. The kinetics of radiation chemical yields of gas products at the irradiation of bituminous oil and its tar fraction have been investigated. Irradiation is conducted in the gamma-ray source of isotope 60Co at the dose rate of P = 0.27 Gy/s and absorbed doses D = 5-163 kGy. It is found that in comparison with oil faction, tar fraction of bituminous oil has a high resistance to radiation.展开更多
Many multicomponent concentrated solid solution alloys(CSAs),including high-entropy alloys(HEAs),exhibit improved radiation resistance and enhanced structural stability in harsh environments.To study and assess irradi...Many multicomponent concentrated solid solution alloys(CSAs),including high-entropy alloys(HEAs),exhibit improved radiation resistance and enhanced structural stability in harsh environments.To study and assess irradiation resistance of nuclear materials,energetic ion and electron beams are commonly used to create displacement damage.Moreover,charged particles of ions,electrons,and positrons are unique tools to create and characterize radiation effects.Ion beam analysis(e.g.,Rutherford backscattering spectrometry,nuclear reaction analysis,and time-of-flight elastic recoil detection analysis),electron microscopy techniques(e.g.,transmission or scanning electron microscopy,and electron diffraction),and positron annihilation spectroscopy have been applied to characterize irradiated CSAs or HEAs to understand defect formation and evolution together with chemical and microstructural information.Their distinctive analyzing power and some perspectives in these techniques are reviewed.In developing structural alloys desirable for applications in advanced reactors,neutron exposure is a critical test but the limitation in achievable high damage levels is,however,a bottleneck.Ion irradiation is often used as a surrogate for neutron irradiation,and the associated reduced transmutations and higher displacements per atom(dpa)rates are desirable for materials research.Nevertheless,cautions need to be taken when relying on ion irradiation results for reactor evaluations.Literature on differences between ions and neutrons is briefly reviewed.In addition,the links to bridge the current advances on fundamental understandings to reactor applications are discussed to lay the groundwork between neutrons and ions for radiation effects studies.展开更多
Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the...Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the practical needs in special radiation environments.Herein we prepared epoxy POSS(e POSS)/SR nanocomposites with excellent thermal stability and radiation resistance.As a physical crosslinking point in the SR,addition of small amount of ePOSS not only enhanced the mechanical properties of the matrix,but also improved its thermal stability greatly due to their good compatibility.e POSS/SR had higher radiation stability in air than SR owing to the inhibition of radiation oxidation by ePOSS,and the yield of main gaseous radiolysis products(CH_(4),H_(2),CO and CO_(2))of SR and ePOSS/SR nanocomposites was determined.By analyzing the changes of chemical structure,thermal properties and mechanical properties of the ePOSS/SR nanocomposite,combined with the characteristics of gas products afterγ-irradiation,the radiation induced crosslinking and degradation mechanism of the nanocomposites was proposed comprehensively.展开更多
[Objectives]Optimum extraction conditions of total flavonoids from Fructus Aurantii Immaturus(TFFAI)and its resistance activity to ultraviolet radiation were investigated in present research.[Methods]The optimal extra...[Objectives]Optimum extraction conditions of total flavonoids from Fructus Aurantii Immaturus(TFFAI)and its resistance activity to ultraviolet radiation were investigated in present research.[Methods]The optimal extraction conditions of TFFAI were determined by single factor and orthogonal experiments,and the survival rate of TFFAI on HaCaT cells irradiated with UVB rays was investigated.It s antioxidant capacity was determined by ABTS.[Results]The results showed that the highest yield of TFFAI was obtained with 70%ethanol at a solid-to-liquid ratio of 1:50(w/v)and 40℃for 1.5 h by single-factor and orthogonal experiments.Total flavonoids(0.25-1.00 mg/ml)could significantly improve the survival rate of HaCaT cell line.Meanwhile,the maximum absorption peak of TFFAI was found at 283 nm,and in-vitro antioxidant experiment identified that TFFAI had a good clearance rate to ABTS.It suggestes that TFFAI could protect the cells from UVB damage by absorption of UVB rays and anti-oxidation.[Conclusions]TFFAI played a protective role on UVB irradiated cells through UVB ultraviolet absorption and antioxidant pathways.展开更多
The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that a...The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that after the photodiodes being irradiated,the photocurrent decreases,especially for short wavelength of light. The dark current of the photodiodes with smaller active area decreases while increases for that with larger active area,and the response time shortens. The plane scanning experiment of laser beam indicates that the homogeneity of the device's surface is not influenced by the irradiation. The results prove that PIN photodiode shows relatively good radioresistance.展开更多
The phenomenon of mutual compensation of radiation donors and acceptors is discovered in IrtAs-InP solid solutions. This phenomenon is a result of opposite directed radiation processes, taking place in the irradiated ...The phenomenon of mutual compensation of radiation donors and acceptors is discovered in IrtAs-InP solid solutions. This phenomenon is a result of opposite directed radiation processes, taking place in the irradiated InAs-InP solid solutions. The radiation creates donor type defects in the sublattice of InAs and electrons concentration increases. The contrary process occurs in the sublattice of InP. Radiation originates acceptor type defects and the carrier concentration decreases. The noted effect is going on in the all alloy composition. Exact mutual compensation of radiation donors and acceptors is achieved by selecting of the alloys definite composition. As a result, the main parameter of semiconductors-electrons concentration remains constant even under the hard radiation with fluences of Ф = 2 × 10^18 fast neutrons/cm^2. So there has been created radiation-resistant material.展开更多
Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predi...Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predicting the decrease of speed on a ship operating at sea. Furthermore, it is also significant to investigate the added resistance for a ship functioning in short waves of large modern ships. The researcher presents an estimation formula for the calculation of an added resistance study in short waves derived from the reflection law. An improved method has been proposed to calculate the added resistance due to ship motions, which applies the radiated energy theory along with the strip method. This procedure is based on an extended integral equation (EIE) method, which was used for solving the hydrodynamic coefficients without effects of the irregular frequency. Next, a combined method was recommended for the estimation of added resistance for a ship in the whole wave length range. The comparison data with other experiments indicate the method presented in the paper provides satisfactory results for large blunt ship.展开更多
MC (Monte Carlo) simulation code, JA-IPU is used to study radiation damage of SiC irradiated to spallation neutron and AmBe neutron spectra. The code is based on the major physical processes of radiation damage on i...MC (Monte Carlo) simulation code, JA-IPU is used to study radiation damage of SiC irradiated to spallation neutron and AmBe neutron spectra. The code is based on the major physical processes of radiation damage on incorporation of atomic collision cascade and limited to 10 MeV neutron energy. A phenomenological relation for radiation swelling is also derived. Based on the calculation of swelling, DPA (displacement per atom), defect production efficiency and effective threshold energy, Efff from the data of MC simulation, SiC is inferred to be a highly radiation resistant material when compared with Nb and Ni metals which are used in composition of several reactor steels. Experimental results of hill-hock density measured using AFM (atomic force microscopy), also confirm radiation resistant behavior of SiC.展开更多
AIM: To study the cancer stem cell population in esophageal cancer cell lines KYSE-150 and TE-1 and identify whether the resulting stem-like spheroid cells display cancer stem cells and radiation resistance characteri...AIM: To study the cancer stem cell population in esophageal cancer cell lines KYSE-150 and TE-1 and identify whether the resulting stem-like spheroid cells display cancer stem cells and radiation resistance characteristics.展开更多
The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE....The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE. To solve this problem, a prototype based on a complementary metal oxide semiconductor(CMOS) pixel sensor, i.e., TopmetalM, was designed for SEE localization. A beam test was performed on the prototype at the radiation terminal of the Heavy Ion Research Facility in Lanzhou(HIRFL). The results indicated that the inherent deflection angle of the prototype to the beam was 1.7°, and the angular resolution was 0.6°. The prototype localized heavy ions with a position resolution of 3.4 μm.展开更多
A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg gratin...A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating(FBG)underg-ray irradiation environment.The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18℃to 40℃before theγ-ray irradiation were about 4.57´10^(-4)dB/℃and 5.48 pm/℃,respectively.The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under theγ-ray irradiation with the total dose of 22.85 kGy at 35℃were about 0.03 dB/m and 0.12 nm,respectively,with theγ-ray irradiation sensitivity of 5.25´10^(-3)pm/Gy.The temperature and theγ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18℃to 40℃and theγ-ray irradiation with the total dose of 22.85 kGy at 35℃,respectively.Furthermore,the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of theγ-ray irradiation.However,no influence on the reflection power of the Bragg wavelengths and the full width at half maximum(FWHM)bandwidth under temperature and theγ-ray irradiation change was found.Also,after theγ-ray irradiation with the dose of 22.85 kGy,no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.展开更多
In the environment of space radiation, the high-energy charged particles or high-energy photons acting on a spacecraft can cause either temporary device degradation or permanent failure. The traditional probability mo...In the environment of space radiation, the high-energy charged particles or high-energy photons acting on a spacecraft can cause either temporary device degradation or permanent failure. The traditional probability model is difficult to obtain reliable estimation of unit radiation resistance performance with small samples. Considering that different products will change differently after high-energy particle radiation, we construct a model based on the gamma degradation process. This model can efficiently describe the law of unit radiation resistance variation with the total radiation dose levels under the effect of the total dose and displacement damage. Finally, the proposed model is used to assess the anti-radiation performance of the N-channel power MOSFET device STRH60N20FSY3 produced by STM to obtain average unit radiation resistance, survival probability, survival function, etc.展开更多
Excellent radiation resistance is a prerequisite for pressure-sensitive hydrogels to be used in high-energy radiation environments. In this work, tannic acid-modified boron nitride nanosheet(BNNS-TA) is first prepared...Excellent radiation resistance is a prerequisite for pressure-sensitive hydrogels to be used in high-energy radiation environments. In this work, tannic acid-modified boron nitride nanosheet(BNNS-TA) is first prepared as the radiation-resistant additive by a facile one-step ball milling of hexagonal boron nitride and tannic acid. Then, polyacrylamide(PAAm)-based pressure-sensitive hydrogel doped with BNNS-TA and Fe^(3+)ions is fabricated. The ternary BNNS-TA/Fe^(3+)/PAAm hydrogel exhibits excellent compressive strength(at least four times the compressive strength of unfilled pure PAAm hydrogel), pressure-sensitive performance(gauge factor is up to 1.4), and performance recovery due to the combination of multiple intermolecular interactions, such as covalent crosslinking, hydrogen bonds, and ion coordination interactions.The BNNS-TA/Fe^(3+)/PAAm hydrogel can be made as a pressure sensor installed in the control circuit or attached on the human body to detect human activities accurately. More importantly, the compressive strength and the pressure-sensitive performance of the BNNS-TA/Fe^(3+)/PAAm hydrogel can be maintained after the hydrogel is irradiated by^(60)Co gamma-ray at an absorbed dose of 15 k Gy. As a comparison, the compressive strength of the unfilled PAAm hydrogel is only a quarter of that before irradiation. This work not only reveals a facile method to achieve the preparation of chemically modified BNNS as a promising radiation-resistant additive but also provides a novel strategy for the development of pressure-sensitive hydrogel devices in radiation environments.展开更多
Engineering materials for nuclear reactors exposed to high-dose irradiation breed various radiation damage,leading to performance degradation of materials,which seriously limits the application of materials in the fut...Engineering materials for nuclear reactors exposed to high-dose irradiation breed various radiation damage,leading to performance degradation of materials,which seriously limits the application of materials in the future advanced nuclear reactors.Tungsten-based materials applied in future nuclear reactors have to withstand not only the attack of high-energy neutron and plasma,but also the repeated impact of steady-state or even transient thermal load.Researches in the past decades have proved that tailored nanostructure have advantage in annihilating radiation defects.With the rapid development of nanostructured tungsten,probing radiation application of nanostructured tungsten is of great significance in promoting the development of novel radiation-resistant materials.Herein,the development status of three kinds of nanostructured tungsten namely nanocrystalline,nanofilm and nanoporous tungsten designed for radiation tolerance and the performance enhancement mechanism of diverse nanostructure in irradiation environment is reviewed.Finally,future perspectives and technical challenges are discussed,to inspire more creative designs of novel nanostructured tungsten for radiation tolerance.展开更多
Purpose/Objective(s): Discovery of genetic drivers of radioresistance is critical for developing novel therapeuticstrategies to combine with radiotherapy of radioresistant PDAC. In this study, we used genome-wide RNA-...Purpose/Objective(s): Discovery of genetic drivers of radioresistance is critical for developing novel therapeuticstrategies to combine with radiotherapy of radioresistant PDAC. In this study, we used genome-wide RNA-seq toidentify genes upregulated in generated radioresistant PDAC cell lines and discovered the Inhibitor of DNA Binding1 (ID1) gene as a potential regulator of radioresistance in PDAC.Materials/Methods: Radioresistant clones of the PDAC cell lines MIA PaCa-2 and PANC-1 were generated bydelivering daily ionizing irradiation (IR) (2 Gy/day) in vitro over two weeks (total 20 Gy) followed by standardclonogenic assays following one week from the end of IR. The generated RR and parental cell lines were submittedfor RNA-seq analysis to identify differentially expressed genes. The Limma R package was used to calculatedifferential expression among genes. Log2 fold change values were calculated for each sample compared to thecontrol. Genes with an absolute fold change > 1 were considered significant. RNA sequencing expression data fromthe Cancer Genome Atlas (TCGA) database was analyzed through the online databases GEPIA, cBioPortal, and theHuman Protein Atlas.Results: Following exposure to two weeks of 2 Gy daily IR in vitro, the two PDAC cell lines showed significantlygreater clonogenic cell survival than their parental cell lines, indicating enhanced RR in these cells. RNA-seqanalysis comparing parental and RR cell lines found upregulated seven genes (TNS4, ZDHHC8P1, APLNR, AQP3,SPP1, ID1, ID2) and seven genes downregulated (PTX3, ITGB2, EPS8L1, ALDH1L2, KCNT2, ARHGAP9, IFI16) in bothRR cell lines. Western blotting confirmed increased expression of the ID1 protein in the RR cell lines compared totheir parental cell lines. We found that ID1 mRNA was significantly higher in PDAC tumors compared to matchednormal and high ID1 expression correlated with significantly worse disease-free survival (DFS) in PDAC patients(HR = 2.2, log rank P = 0.009). ID1 mRNA expression was also strongly correlated in tumors with TP53 mutation, aknown driver of radioresistance.Conclusion: Our analysis indicates a novel role of ID1 in PDAC radioresistance. ID1 expression is higher in tumortissue compared to normal, and high expression correlates with both worse DFS and association with the TP53mutation, suggesting that targeting ID1 prior to IR is an attractive strategy for overcoming radioresistance in PDAC.展开更多
Semiconductor-based neutron-detectors are characterized by small size, high energy-resolution, good spatial resolution, and stable response(at the depletion voltage). Consequently, these neutron-detectors are importan...Semiconductor-based neutron-detectors are characterized by small size, high energy-resolution, good spatial resolution, and stable response(at the depletion voltage). Consequently, these neutron-detectors are important for the fields of nuclear proliferation prevention, oil exploration, monitoring neutron-scattering experiments, cancer treatments, and space radiation effect research. However, there are some well-known problems for conventional silicon-based neutron detectors: low neutron-detection efficiency and limited resistance to radiation. Therefore, critical improvements are needed to enable sufficiently effective and practical neutron detection. To address these problems, direct-conversion neutron detectors as well as wide bandgap semiconductor-based detectors have been developed and studied intensely during the past years. Significant progress with respect to detection efficiency, radiation resistance, and room temperature operation was achieved. This paper reviews the latest research highlights, remaining challenges, and emerging technologies of direct-conversion neutron detectors as well as wide-bandgap semiconductor neutron detectors. This compact review serves as a reference for researchers interested in the design and development of improved neutron detectors in the future.展开更多
The recent achievement of fusion ignition with laser-driven technologies at the National Ignition Facility sets a historic accomplishment in fusion energy research.This accomplishment paves the way for using laser ine...The recent achievement of fusion ignition with laser-driven technologies at the National Ignition Facility sets a historic accomplishment in fusion energy research.This accomplishment paves the way for using laser inertial fusion as a viable approach for future energy production.Europe has a unique opportunity to empower research in this field internationally,and the scientific community is eager to engage in this journey.We propose establishing a European programme on inertial-fusion energy with the mission to demonstrate laser-driven ignition in the direct-drive scheme and to develop pathway technologies for the commercial fusion reactor.The proposed roadmap is based on four complementary axes:(ⅰ)the physics of laser-plasma interaction and burning plasmas;(ⅱ)high-energy high repetition rate laser technology;(ⅲ)fusion reactor technology and materials;and(ⅳ)reinforcement of the laser fusion community by international education and training programmes.We foresee collaboration with universities,research centres and industry and establishing joint activities with the private sector involved in laser fusion.This project aims to stimulate a broad range of high-profile industrial developments in laser,plasma and radiation technologies along with the expected high-level socio-economic impact.展开更多
基金supported by grants from the National Natural Science Foundation of China(Nos.81201820,81101691)supported by Specialized Research Fund for the Doctoral Program of Higher Education(No.20100142120041)
文摘Summary: The purpose of this study was to investigate the molecular mechanism by which miR-21 and its target genes mediate radiation resistance of glioblastoma cells. Real-time PCR was employed to detect miR-21 expression in normal brain tissues, glioblastoma tissues and glioblastoma cell lines (A172, T98G and U87MG). T98G cells were transfected with anti-miR-21 oligonucleotides, or plasmids con- taining PDCD4 or hMSH2 (PDCD4-pcDNA3 and hMSH2-pcDNA3). The survival curve was obtained to investigate the sensitivity of T98G cells to radiation. Cell apoptosis was measured by using the Cas- pase-3/7 kit and cell cycle by flow cytometry. Western blotting was performed to detect the expression of hMSH2 and PDCD4 in miR-21-inhibiting T98G cells. The results showed that miR-21 expression in glioblastoma cells and tissues was conversely associated with the radiation sensitivity. Over-expression of miR-21 resulted in radiation resistance, while knockdown of miR-21 led to higher sensitivity of glioblastma cells to radiation. After miR-21 knockdown, the apoptosis of T98G cells was significantly increased and the G2 phase arrest was more significant. In addition, miR-21 knockdown increased the expression of endogenous PDCD4 and hMSH2, which contributed to the apoptosis and G2 arrest of T98G cells. The findings suggested that miR-21 may mediate the resistance of glioblastoma cells against radiation via its target genes PDCD4 and hMSH2. MiR-21 and its target genes may be used as potential molecular targets for clinical radiotherapy sensitization in the future.
文摘The radiation damage responses of ttuorinated and non-fluorinated lateral PNP transistors are studied with specially designed gated-controlled lateral PNP transistors that allow for the extraction of the oxide trapped charge (Not) and interface trap (Nit) densities. All the samples are exposed in the Co-60γ ray with the dose rate of 0.5 Gy(Si)/s. After the irradiation, the buildup of Not and Nit of the samples with total dose is investigated by the gate sweep test technique. The results show that the radiation resistance of fluorinated lateral PNP transistors is significantly enhanced compared with the non-fluorinated ones.
基金supported by China National Funds for Guangdong Key Research and Development Program(Grant No.2018B090904001)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(Grant No.2017BT01X137)+2 种基金Key Laboratory of Laser Device Technology Foundation of China Ordnance Industry Group Co.(Grant No.KLLDT202010)the Key R&D Program of Guangzhou(Grant No.202007020003)the National Natural Science Foundation of China(Grant No.52002131)。
文摘Effects of Nb_(2)O_(5)dopant on the radiation response of barium gallo-germanate(BGG)glass are studied mainly by electron paramagnetic resonance and absorption spectroscopy.Owing to the Nb^(5+)$Nb^(3+)interconversion in doped samples,formations of Ge-related non-bridging oxygen hole center and Ge-related electron center defects after g-ray irradiation are inhibited.Thereby,Nb_(2)O_(5)dopant can enhance radiation resistance of BGG glass,and 1.0%Nb2O5 concentration is the best.
文摘The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR (infrared) spectra of initial and irradiated samples of tar fractions of bituminous oil are compared. The kinetics of radiation chemical yields of gas products at the irradiation of bituminous oil and its tar fraction have been investigated. Irradiation is conducted in the gamma-ray source of isotope 60Co at the dose rate of P = 0.27 Gy/s and absorbed doses D = 5-163 kGy. It is found that in comparison with oil faction, tar fraction of bituminous oil has a high resistance to radiation.
基金supported as part of Energy Dissipation to Defect Evolution(EDDE)an Energy Frontier Research Center funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,under contract number DE-AC05-00OR22725.
文摘Many multicomponent concentrated solid solution alloys(CSAs),including high-entropy alloys(HEAs),exhibit improved radiation resistance and enhanced structural stability in harsh environments.To study and assess irradiation resistance of nuclear materials,energetic ion and electron beams are commonly used to create displacement damage.Moreover,charged particles of ions,electrons,and positrons are unique tools to create and characterize radiation effects.Ion beam analysis(e.g.,Rutherford backscattering spectrometry,nuclear reaction analysis,and time-of-flight elastic recoil detection analysis),electron microscopy techniques(e.g.,transmission or scanning electron microscopy,and electron diffraction),and positron annihilation spectroscopy have been applied to characterize irradiated CSAs or HEAs to understand defect formation and evolution together with chemical and microstructural information.Their distinctive analyzing power and some perspectives in these techniques are reviewed.In developing structural alloys desirable for applications in advanced reactors,neutron exposure is a critical test but the limitation in achievable high damage levels is,however,a bottleneck.Ion irradiation is often used as a surrogate for neutron irradiation,and the associated reduced transmutations and higher displacements per atom(dpa)rates are desirable for materials research.Nevertheless,cautions need to be taken when relying on ion irradiation results for reactor evaluations.Literature on differences between ions and neutrons is briefly reviewed.In addition,the links to bridge the current advances on fundamental understandings to reactor applications are discussed to lay the groundwork between neutrons and ions for radiation effects studies.
基金financially supported by the Science Challenge Project(No.TZ2018004)the National Natural Science Foundation of China(NSFC,Nos.11575009 and 12075010)。
文摘Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the practical needs in special radiation environments.Herein we prepared epoxy POSS(e POSS)/SR nanocomposites with excellent thermal stability and radiation resistance.As a physical crosslinking point in the SR,addition of small amount of ePOSS not only enhanced the mechanical properties of the matrix,but also improved its thermal stability greatly due to their good compatibility.e POSS/SR had higher radiation stability in air than SR owing to the inhibition of radiation oxidation by ePOSS,and the yield of main gaseous radiolysis products(CH_(4),H_(2),CO and CO_(2))of SR and ePOSS/SR nanocomposites was determined.By analyzing the changes of chemical structure,thermal properties and mechanical properties of the ePOSS/SR nanocomposite,combined with the characteristics of gas products afterγ-irradiation,the radiation induced crosslinking and degradation mechanism of the nanocomposites was proposed comprehensively.
基金Supported by National Key Program of Innovation and Entrepreneurship Training for College Students (202211834021)Project Funds of Zhengzhou Science and Technology Bureau (ZZSZX202109).
文摘[Objectives]Optimum extraction conditions of total flavonoids from Fructus Aurantii Immaturus(TFFAI)and its resistance activity to ultraviolet radiation were investigated in present research.[Methods]The optimal extraction conditions of TFFAI were determined by single factor and orthogonal experiments,and the survival rate of TFFAI on HaCaT cells irradiated with UVB rays was investigated.It s antioxidant capacity was determined by ABTS.[Results]The results showed that the highest yield of TFFAI was obtained with 70%ethanol at a solid-to-liquid ratio of 1:50(w/v)and 40℃for 1.5 h by single-factor and orthogonal experiments.Total flavonoids(0.25-1.00 mg/ml)could significantly improve the survival rate of HaCaT cell line.Meanwhile,the maximum absorption peak of TFFAI was found at 283 nm,and in-vitro antioxidant experiment identified that TFFAI had a good clearance rate to ABTS.It suggestes that TFFAI could protect the cells from UVB damage by absorption of UVB rays and anti-oxidation.[Conclusions]TFFAI played a protective role on UVB irradiated cells through UVB ultraviolet absorption and antioxidant pathways.
文摘The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that after the photodiodes being irradiated,the photocurrent decreases,especially for short wavelength of light. The dark current of the photodiodes with smaller active area decreases while increases for that with larger active area,and the response time shortens. The plane scanning experiment of laser beam indicates that the homogeneity of the device's surface is not influenced by the irradiation. The results prove that PIN photodiode shows relatively good radioresistance.
文摘The phenomenon of mutual compensation of radiation donors and acceptors is discovered in IrtAs-InP solid solutions. This phenomenon is a result of opposite directed radiation processes, taking place in the irradiated InAs-InP solid solutions. The radiation creates donor type defects in the sublattice of InAs and electrons concentration increases. The contrary process occurs in the sublattice of InP. Radiation originates acceptor type defects and the carrier concentration decreases. The noted effect is going on in the all alloy composition. Exact mutual compensation of radiation donors and acceptors is achieved by selecting of the alloys definite composition. As a result, the main parameter of semiconductors-electrons concentration remains constant even under the hard radiation with fluences of Ф = 2 × 10^18 fast neutrons/cm^2. So there has been created radiation-resistant material.
基金Supported by the National Natural Science Foundation of China under Grant No.51079032 the Outstanding Youth Science Foundation of Heilongjiang Province,No.200908
文摘Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predicting the decrease of speed on a ship operating at sea. Furthermore, it is also significant to investigate the added resistance for a ship functioning in short waves of large modern ships. The researcher presents an estimation formula for the calculation of an added resistance study in short waves derived from the reflection law. An improved method has been proposed to calculate the added resistance due to ship motions, which applies the radiated energy theory along with the strip method. This procedure is based on an extended integral equation (EIE) method, which was used for solving the hydrodynamic coefficients without effects of the irregular frequency. Next, a combined method was recommended for the estimation of added resistance for a ship in the whole wave length range. The comparison data with other experiments indicate the method presented in the paper provides satisfactory results for large blunt ship.
文摘MC (Monte Carlo) simulation code, JA-IPU is used to study radiation damage of SiC irradiated to spallation neutron and AmBe neutron spectra. The code is based on the major physical processes of radiation damage on incorporation of atomic collision cascade and limited to 10 MeV neutron energy. A phenomenological relation for radiation swelling is also derived. Based on the calculation of swelling, DPA (displacement per atom), defect production efficiency and effective threshold energy, Efff from the data of MC simulation, SiC is inferred to be a highly radiation resistant material when compared with Nb and Ni metals which are used in composition of several reactor steels. Experimental results of hill-hock density measured using AFM (atomic force microscopy), also confirm radiation resistant behavior of SiC.
基金Supported by Leading Scientific Research Project of the Health Department of Jiangsu Province,China,No.Z201220Major Project of the Health Department of Changzhou,China,No.ZD201105Changzhou Sci-Tech Support Project for Social Development,No.CE20125021
文摘AIM: To study the cancer stem cell population in esophageal cancer cell lines KYSE-150 and TE-1 and identify whether the resulting stem-like spheroid cells display cancer stem cells and radiation resistance characteristics.
基金supported by the National Natural Science Foundation of China(No.U1932143),the National Key Research and Development Program of China(No.2020YFE0202002)the National Natural Science Foundation of China(Nos.11875146,11927901,12075099,12075100,11875145,U2032209)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34000000).
文摘The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE. To solve this problem, a prototype based on a complementary metal oxide semiconductor(CMOS) pixel sensor, i.e., TopmetalM, was designed for SEE localization. A beam test was performed on the prototype at the radiation terminal of the Heavy Ion Research Facility in Lanzhou(HIRFL). The results indicated that the inherent deflection angle of the prototype to the beam was 1.7°, and the angular resolution was 0.6°. The prototype localized heavy ions with a position resolution of 3.4 μm.
基金This work was partially supported by the Korea Electric Power Corporation Research Institute(Grant No.KEPRI-16-23)the Korea Industrial Complex Corporation Industrial Cluster Competitiveness Enhancement Project(Grant No.RGJ18014),South Korea.
文摘A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating(FBG)underg-ray irradiation environment.The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18℃to 40℃before theγ-ray irradiation were about 4.57´10^(-4)dB/℃and 5.48 pm/℃,respectively.The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under theγ-ray irradiation with the total dose of 22.85 kGy at 35℃were about 0.03 dB/m and 0.12 nm,respectively,with theγ-ray irradiation sensitivity of 5.25´10^(-3)pm/Gy.The temperature and theγ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18℃to 40℃and theγ-ray irradiation with the total dose of 22.85 kGy at 35℃,respectively.Furthermore,the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of theγ-ray irradiation.However,no influence on the reflection power of the Bragg wavelengths and the full width at half maximum(FWHM)bandwidth under temperature and theγ-ray irradiation change was found.Also,after theγ-ray irradiation with the dose of 22.85 kGy,no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.
基金supported by the National Natural Science Foundation of China(Grant Nos.71371067&70901024)Hunan Provincial Natural Science Foundation of China
文摘In the environment of space radiation, the high-energy charged particles or high-energy photons acting on a spacecraft can cause either temporary device degradation or permanent failure. The traditional probability model is difficult to obtain reliable estimation of unit radiation resistance performance with small samples. Considering that different products will change differently after high-energy particle radiation, we construct a model based on the gamma degradation process. This model can efficiently describe the law of unit radiation resistance variation with the total radiation dose levels under the effect of the total dose and displacement damage. Finally, the proposed model is used to assess the anti-radiation performance of the N-channel power MOSFET device STRH60N20FSY3 produced by STM to obtain average unit radiation resistance, survival probability, survival function, etc.
基金supported by the National Natural Science Foundation of China (Nos.51773189 and 51973205)the Joint Laboratory for University of Science and Technology of China and Yanchang Petroleum (No.ES2060200084)the Fundamental Research Funds for the Central Universities (Nos.WK3450000005,WK3450000006)。
文摘Excellent radiation resistance is a prerequisite for pressure-sensitive hydrogels to be used in high-energy radiation environments. In this work, tannic acid-modified boron nitride nanosheet(BNNS-TA) is first prepared as the radiation-resistant additive by a facile one-step ball milling of hexagonal boron nitride and tannic acid. Then, polyacrylamide(PAAm)-based pressure-sensitive hydrogel doped with BNNS-TA and Fe^(3+)ions is fabricated. The ternary BNNS-TA/Fe^(3+)/PAAm hydrogel exhibits excellent compressive strength(at least four times the compressive strength of unfilled pure PAAm hydrogel), pressure-sensitive performance(gauge factor is up to 1.4), and performance recovery due to the combination of multiple intermolecular interactions, such as covalent crosslinking, hydrogen bonds, and ion coordination interactions.The BNNS-TA/Fe^(3+)/PAAm hydrogel can be made as a pressure sensor installed in the control circuit or attached on the human body to detect human activities accurately. More importantly, the compressive strength and the pressure-sensitive performance of the BNNS-TA/Fe^(3+)/PAAm hydrogel can be maintained after the hydrogel is irradiated by^(60)Co gamma-ray at an absorbed dose of 15 k Gy. As a comparison, the compressive strength of the unfilled PAAm hydrogel is only a quarter of that before irradiation. This work not only reveals a facile method to achieve the preparation of chemically modified BNNS as a promising radiation-resistant additive but also provides a novel strategy for the development of pressure-sensitive hydrogel devices in radiation environments.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U1867215,11875211,U1932134,12074293 and 12025503)Hubei Provincial Natural Science Foundation(Grant No.2019CFA036)the Fundamental Research Funds for the Central Universities(Grant No.2042020kf0211)
文摘Engineering materials for nuclear reactors exposed to high-dose irradiation breed various radiation damage,leading to performance degradation of materials,which seriously limits the application of materials in the future advanced nuclear reactors.Tungsten-based materials applied in future nuclear reactors have to withstand not only the attack of high-energy neutron and plasma,but also the repeated impact of steady-state or even transient thermal load.Researches in the past decades have proved that tailored nanostructure have advantage in annihilating radiation defects.With the rapid development of nanostructured tungsten,probing radiation application of nanostructured tungsten is of great significance in promoting the development of novel radiation-resistant materials.Herein,the development status of three kinds of nanostructured tungsten namely nanocrystalline,nanofilm and nanoporous tungsten designed for radiation tolerance and the performance enhancement mechanism of diverse nanostructure in irradiation environment is reviewed.Finally,future perspectives and technical challenges are discussed,to inspire more creative designs of novel nanostructured tungsten for radiation tolerance.
文摘Purpose/Objective(s): Discovery of genetic drivers of radioresistance is critical for developing novel therapeuticstrategies to combine with radiotherapy of radioresistant PDAC. In this study, we used genome-wide RNA-seq toidentify genes upregulated in generated radioresistant PDAC cell lines and discovered the Inhibitor of DNA Binding1 (ID1) gene as a potential regulator of radioresistance in PDAC.Materials/Methods: Radioresistant clones of the PDAC cell lines MIA PaCa-2 and PANC-1 were generated bydelivering daily ionizing irradiation (IR) (2 Gy/day) in vitro over two weeks (total 20 Gy) followed by standardclonogenic assays following one week from the end of IR. The generated RR and parental cell lines were submittedfor RNA-seq analysis to identify differentially expressed genes. The Limma R package was used to calculatedifferential expression among genes. Log2 fold change values were calculated for each sample compared to thecontrol. Genes with an absolute fold change > 1 were considered significant. RNA sequencing expression data fromthe Cancer Genome Atlas (TCGA) database was analyzed through the online databases GEPIA, cBioPortal, and theHuman Protein Atlas.Results: Following exposure to two weeks of 2 Gy daily IR in vitro, the two PDAC cell lines showed significantlygreater clonogenic cell survival than their parental cell lines, indicating enhanced RR in these cells. RNA-seqanalysis comparing parental and RR cell lines found upregulated seven genes (TNS4, ZDHHC8P1, APLNR, AQP3,SPP1, ID1, ID2) and seven genes downregulated (PTX3, ITGB2, EPS8L1, ALDH1L2, KCNT2, ARHGAP9, IFI16) in bothRR cell lines. Western blotting confirmed increased expression of the ID1 protein in the RR cell lines compared totheir parental cell lines. We found that ID1 mRNA was significantly higher in PDAC tumors compared to matchednormal and high ID1 expression correlated with significantly worse disease-free survival (DFS) in PDAC patients(HR = 2.2, log rank P = 0.009). ID1 mRNA expression was also strongly correlated in tumors with TP53 mutation, aknown driver of radioresistance.Conclusion: Our analysis indicates a novel role of ID1 in PDAC radioresistance. ID1 expression is higher in tumortissue compared to normal, and high expression correlates with both worse DFS and association with the TP53mutation, suggesting that targeting ID1 prior to IR is an attractive strategy for overcoming radioresistance in PDAC.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11922507, and 12050005)Major State Basic Research Development Program of China (Grant No. 2021YFB3201000)Fundamental Research Funds for the Central Universities (Grant No.2021NTST14)。
文摘Semiconductor-based neutron-detectors are characterized by small size, high energy-resolution, good spatial resolution, and stable response(at the depletion voltage). Consequently, these neutron-detectors are important for the fields of nuclear proliferation prevention, oil exploration, monitoring neutron-scattering experiments, cancer treatments, and space radiation effect research. However, there are some well-known problems for conventional silicon-based neutron detectors: low neutron-detection efficiency and limited resistance to radiation. Therefore, critical improvements are needed to enable sufficiently effective and practical neutron detection. To address these problems, direct-conversion neutron detectors as well as wide bandgap semiconductor-based detectors have been developed and studied intensely during the past years. Significant progress with respect to detection efficiency, radiation resistance, and room temperature operation was achieved. This paper reviews the latest research highlights, remaining challenges, and emerging technologies of direct-conversion neutron detectors as well as wide-bandgap semiconductor neutron detectors. This compact review serves as a reference for researchers interested in the design and development of improved neutron detectors in the future.
文摘The recent achievement of fusion ignition with laser-driven technologies at the National Ignition Facility sets a historic accomplishment in fusion energy research.This accomplishment paves the way for using laser inertial fusion as a viable approach for future energy production.Europe has a unique opportunity to empower research in this field internationally,and the scientific community is eager to engage in this journey.We propose establishing a European programme on inertial-fusion energy with the mission to demonstrate laser-driven ignition in the direct-drive scheme and to develop pathway technologies for the commercial fusion reactor.The proposed roadmap is based on four complementary axes:(ⅰ)the physics of laser-plasma interaction and burning plasmas;(ⅱ)high-energy high repetition rate laser technology;(ⅲ)fusion reactor technology and materials;and(ⅳ)reinforcement of the laser fusion community by international education and training programmes.We foresee collaboration with universities,research centres and industry and establishing joint activities with the private sector involved in laser fusion.This project aims to stimulate a broad range of high-profile industrial developments in laser,plasma and radiation technologies along with the expected high-level socio-economic impact.