Total dose ionizing irradiation effects on a static random access memory field programmable gate array

SRAM-based FPGA devices are irradiated by ^（60）Coγrays at various aose rates 10 investigate total dose effects and the evaluation method.The dependences of typical electrical parameters such as static power current, peak-peak value,and delay time on total dose are discussed.The experiment results show that the static power current of the devices reduces rapidly at room temperature（25℃） and high temperature（80℃） annealing after irradiation.When the device is irradiated at a low dose rate,the delay time and peak-peak value change unobviously with an increase in the accumulated dose.In contrast,the function parameters completely fail at 2.1 kGy（Si） when the dose rate increases to 0.71 Gy（Si）/s.

Influence of Total Ionizing Dose Irradiation on Low-Frequency Noise Responses in Partially Depleted SOI nMOSFETs

Total ionizing dose effect induced low frequency degradations in 130nm partially depleted silicon-on-insulator （SOI） technology are studied by ^60Co γ -ray irradiation. The experimental results show that the flicker noise at the front gate is not affected by the radiation since the radiation induced trapped charge in the thin gate oxide can be ignored. However, both the Lorenz spectrum noise, which is related to the linear kink effect （LKE） at the front gate, and the flicker noise at the back gate are sensitive to radiation. The radiation induced trapped charge in shallow trench isolation and the buried oxide can deplete the nearby body region and can activate the traps which reside in the depletion region. These traps act as a GR center and accelerate the consumption of the accumulated holes in the floating body. It results in the attenuation of the LKE and the increase of the Lorenz spectrum noise. Simultaneously, the radiation induced trapped charge in the buried oxide can directly lead to an enhanced flicker noise at the back gate. The trapped charge density in the buried oxide is extracted to increase from 2.21×10^18 eV^-1 cm^-3 to 3.59×10^18？eV^-1 cm^-3 after irradiation.

Radiolysis of pentachlorophenol (PCP) in aqueous solution by gamma radiation

Steady-state radiolysis experiments were performed to investigate the γ-irradiation treatment of pentachlorophenol (PCP) in aqueous solution. The e?ect of initial concentration on the PCP degradation was also investigated. The experimental results showed that γirradiation was able to degrade PCP in aqueous solution successfully, and the radiolytical degradation process of PCP could be described by the first-order kinetic model. When the initial concentration of PCP was 25 and 50 mg/L and the radiation dose ...

Effects of 3-aminobenzamide on poly(ADP-ribose)polymerase expression,apoptosis and cell cycle progression of HeLa cells after X-ray irradiation

The aim of this paper is to study the changes of apoptosis and cell cycle progression in HeLa cells after the poly(ADP-ribose)polymerase(PARP)was inhibited by its inhibitor 3-aminobenzamide(3-AB)and the mechan-isms of PARP action on HeLa cells damaged by irra-diation.Flow cytometry(FCM)was used to examine the PARP expression and the percentage of apoptotic cells and cell cycle progression.The percentage of HeLa cells with positive expression of PARP protein 2,4,8 and 12 h after administrated with 3-AB was significantly lower than that of the control(P<0.01).The percentages of apoptotic cells in the 3-AB plus irradiation group at the time points of 2,8,12 and 24 h after 2 Gy irradiation were higher than that in the irradiation group(P<0.01 or P<0.05)and the percentage of G2 cells decreased signifi-cantly(P<0.01 or P<0.05).It indicates that 3-AB can rapidly inhibit PARP expression of HeLa cells,promote cell apoptosis and block G2 arrest induced by irradiation.

BRCA1 and its phosphorylation involved in caffeine-inhibitable event upstream of G2 checkpoint

Caffeine,which specifically inhibits ATM/ATR kinases,efficiently abrogates the ionizing radiation(IR)-induced G2 arrest and increases the sensitivity of various tumor cells to IR.Mechanisms for the effect of caffeine remain to be elucidated.As a target of ATM/ATR kinases,BRCA1 becomes activated and phosphorylated in response to IR.Thus,in this work,we investigated the possible role of BRCA1 in the effect of caffeine on G2 checkpoint and observed how BRCA1 phosphorylation was regulated in this process.For these purposes,the BRCA1 protein level and the phosphorylation states were analyzed by Western blotting by using an antibody against BRCA1 and phospho-specific antibodies against Ser-1423 and Ser-1524 residues in cells exposed to a combination of IR and caffeine.The results showed that caffeine down-regulated IR-induced BRCA1 expression and specifically abolished BRCA1 phosphorylation of Ser-1524,which was followed by an override of G2 arrest by caffeine.In addition,the ability of BRCA1 to transactivate p21 may be required for MCF-7 but not necessary for Hela response to caffeine.These data suggest that BRCA1 may be a potential target of caffeine.BRCA1 and its phosphorylation are most likely to be involved in the caffeine-inhibitable event upstream of G2 arrest.