ABSTRACT
Uranium is renowned as a global contaminant, and attracts major concern with regards to the health risks involved because its nephrotoxicity. This paper discusses the development of a simple method to identify accumulated regions or localized sites of uranium within kidneys using the CR-39 plastic nuclear track detector. To demonstrate the proposed method, renal cryo-sections (5 µm-t) from Wistar male rats, subcutaneously administered with uranyl acetate (2 mg/kg), were prepared on day one after administration. Concerned sections were subsequently placed on CR-39, stored for 1.25 years, and then etched in a 7 M NaOH solution at 70°C for 3 h. α-tracks were then detected in the form of etch pits, corresponding to uranium, and also the tissue shape and structure were transferred as a roughness on the surface of CR-39. As observed, the proposed method served to facilitate simultaneous detection and identification of localized regions of uranium accumulation within kidneys.
Subject(s)
Kidney/radiation effects , Radiometry/methods , Uranium/toxicity , Animals , Male , Organometallic Compounds , Polyethylene Glycols , Rats , Rats, WistarABSTRACT
It is believed that the dose-rate of radiation will have an influence on cell sensitivity. The dose-rate effects on cell survival can be expressed by the change of the ß term in the linear quadratic model. The value at a high-dose-rate decreases below 60 Gy/h and reaches zero at 0.2 Gy/h or less for photons. However, the effect for a high-LET ion-beam is not well known. At HIMAC, cells were exposed to 70 keV/µm carbon-ion beams at different dose-rates between 0.5 and 600 Gy/h at room temperature. The ß values for all survival curves show no significant differences among the dose-rates tested for HSG, V79 and CHO cells. Changing the ion-beam dose-rate had no effect on cell survival. This suggests that high-LET particle beams, such as galactic cosmic rays, may not exhibit a dose-rate effect on cell survival. Low-dose-rate radiation showed an effect similar to high-dose-rate radiation.
Subject(s)
Cell Survival/radiation effects , Cells, Cultured/radiation effects , Linear Energy Transfer , Animals , Carbon , Cosmic Radiation , Cricetinae , Dose-Response Relationship, Radiation , Humans , IonsABSTRACT
Theoretical and experimental analyses have been performed to examine the position resolution of a proportional counter with a 7-microm diameter carbon fiber as a resistive anode, which is used to encode one-dimensional positions of incident photons according to the charge-division method. These analyses have clearly shown that the carbon fiber is applicable to the position sensing of the order of 100-200 microm as long as the filled gas is pressurized at near 10 atm.
