最新刊期
期 6 ， 2018
- 摘要：To investigate the protective effect and potential mechanism of environmental enrichment (EE) on irradiation-induced cognitive dysfunction in mice, thirty-six female Kunming mice were randomly divided into three groups administered different treatments:control, Irradiation (IR), and IR+EE. The mice in IR group and IR+EE group were irradiated with 137Cs g rays at an absorbed dose of 4.0 Gy. Mice in the IR+EE group were housed in EE for 35 d following irradiation. The object recognition task was used to evaluate the cognitive function of mice. The expression of the neurogenesis marker doublecortin (DCX), and phosphorylated cAMP response element-binding protein (p-CREB) was detected by using immunohistochemical staining. The expression of the cAMP response element-binding protein (CREB) and p-CREB proteins in hippocampus was assayed by using western blotting. The results showed that compared with control group, the irradiation group had a low discrimination ratio in the object recognition task (45.55±5.80 vs. 2.99±6.18, p < 0.05), had fewer DCX positive cells (123.8±9.3 vs. 70.2±5.9, p < 0.05), and had a remarkably lower level of p-CREB/CREB (1.007±0.058 vs. 0.772±0.039, p < 0.05). Compared with the IR group, the IR+EE group had an enhanced discrimination ratio (2.99±6.18 vs. 28.31±7.30, p < 0.05), more DCX positive cells (70.2±5.9 vs. 95.7±6.5, p < 0.05), and up-regulated the expression of p-CREB/CREB (0.772±0.039 vs. 1.014±0.093, p < 0.05). The results suggest that EE may alleviate irradiation-induced cognitive dysfunction and impair neurogenesis via enhancing hippocampal p-CREB expression.关键词：Environmental enrichment;Hippocampus;Cyclic adenosine monophosphate (cAMP) response element binding protein (CREB);Cognitive dysfunction;Neurogenesis;Ionizing radiation
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发布时间：2021-12-10 - 摘要：Two designs of planning target volume (PTV) of target margins were derived from the setup errors with or without cone-beam computed tomography (CBCT) online alignment. Different plans were designed with these two sets of PTV target margins using treatment planning systems (TPS). We analyzed dosimetric differences in the target and organ at risk (OAR) caused by different designs of PTV target margins. The two designs of PTV target margins in the X, Y and Z directions, respectively, were as follows:3.73, 5.16 and 4.36 mm and 5.5, 9.89 and 5.83 mm; these designs were derived from setup errors with or without CBCT online alignment. Significant statistical differences (p < 0.05) were found among V30, V40, V50 and Dmean of the bladder and rectum; V20, V30, V40, V50 and Dmean of tne small intestine; V10, V20, V30, V40, V50 and Dmean of the marrow; and V50 and Dmean of the left and right femoral head. Significant statistical differences (p < 0.05) were also found in D2, D5, D50 and Dmean of clinical target volume (CTV), homogeneity index (IH) and conformity index (IC). The dose in the OAR will on the high side if using larger target margin of PTV with CBCT online alignment, and the dose deficiency was significant in the target if using smaller target margin of PTV without CBCT online alignment. CBCT online alignment can reduce the setup errors and improve the accuracy of the patient positioning. The choice of PTV target margin should be related with the choice of CBCT online alignment, so as to avoid dose deficiency in the target and excessive radiation in the OAR to improve the radiotherapy quality.关键词：Cone beam computed tomography;Online alignment technology;Cervical cancer;Radiotherapy;Target margin;Dosimetric difference
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发布时间：2021-12-10
RADIOBIOLOGY AND RADIOMEDICINE
- 摘要：Modified silica particles (V-SiO2) and stearyl acrylate (SA) were grafted onto cotton-fabric via electron-beam (EB) irradiation to achieve hydrophobicity. The effects of absorbed dose, V-SiO2 particle size, mass fraction of the V-SiO2 particles, the mass ratio of particle modifier vinyltrimethoxysilane (VTMS) to tetraethyl orthosilicate (TEOS), and mass fraction of SA on the hydrophobicity of the modified cotton-fabric were investigated. The change in the hydrophobic property was characterized by measuring the water contact angle, spray testing grade, anti-hydrostatic pressure, and water vapor permeability. The results showed that the modified cotton-fabric could attain a water contact angle of 152° from 143°, spray testing grade of 4 from 1, anti-hydrostatic pressure of 264 mm from 130 mm, and water vapor permeability of 10.247 3 g/(m2·h) from 12.367 5 g/(m2·h). Furthermore, the optimized reaction conditions were as followers:V-SiO2 particle size, 240 nm; mass ratio of VTMS to TEOS, 6:1; V-SiO2 mass fraction, 5%; SA mass fraction, 30%; and absorbed dose of EB, 43 kGy.关键词：Hydrophobicity;Cotton fabric;Electron beam;Radiation grafting;Stearyl acrylate;Modified silica
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发布时间：2021-12-10 - 摘要：The aim of the study was to investigate the decontaminating effect of several chelating agents (EDTA·Na2, DTPA, and EDTMPA) and adsorbents (sodium alginate and carboxymethyl chitosan) on Cs+-contaminated wounds. A skin punch was used to establish a model dorsal wound in rats. The stable isotope of radioactive cesium was chosen as the target for wound decontamination. An appropriately concentrated solution of three chelating agents and two adsorbents were used as the decontamination fluid. A disposable surgical lavage system was used to flush the contamination wound, and the flushing fluid was collected. The cesium ion content in the flushing fluid was detected by inductive coupled plasma emission spectrometry, and the decontamination efficiency was calculated. The decontamination efficiency increased with the concentration of EDTA·Na2; the efficiency of 0.6 mol/L EDTA·Na2 reached 74.15%, which was significantly higher than that of saline water (p < 0.01). The decontamination efficiency increased with the concentration of DTPA, but was not significantly different to that of saline water. With the increase of EDTMPA concentrations, the decontamination efficiency first increased and then appeared to decrease. The decontamination efficiency of 0.01 mol/L EDTMPA reached 76.06%, which was significantly higher than that of saline water (p < 0.01). In general, the decontamination efficiency increased with concentrations of sodium alginate and carboxymethyl chitosan. The decontamination efficiency of 3 g/L sodium alginate (68.22%, p < 0.05) and 4 g/L carboxymethyl chitosan (74.22%, p < 0.01) was significantly different compared with that of saline water. The optimization of the decontamination conditions showed that the decontamination efficiency increased with the contamination volume and decontamination fluid volume, and decreased as the increase of contamination time. We concluded that the chelating agents (EDTA·Na2 and EDTMPA) and adsorbents (sodium alginate and carboxymethyl chitosan) have a significant decontaminating effect on Cs+-contaminated wounds, and have the potential to be developed into a highly efficient decontamination detergent for wound contamination.关键词：Radionuclide;Cesium ion;Chelating agent;Adsorbent;Rats;Wound decontamination
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发布时间：2021-12-10 - 摘要：Magnetic zeolite was prepared by combining modified zeolite with Fe3O4 by a physical adhesion process based on magnetic carrier technology. The composition of the resulting material was determined by X-ray diffraction, scanning electron microscopy, and magnetization measurements. The adsorption capacity of the magnetic zeolite for Cs ions and the magnetic recovery rate were also studied. The results showed that the Fe3O4 particles adhered to the magnetic zeolite surface or aggregated to one another, forming magnetic particulates. As opposed to the case of Na-zeolite, there was no change in the structure of the magnetic zeolite. The removal rate of Cs ions from the magnetic zeolite increased rapidly with an increase in the adsorption time, after 240 min, increased slowly. After 16 h, the Cs ion adsorption reached the maximum value. The maximum adsorption capacity for Cs ions reached 78 mg/g, and the saturation magnetization of the magnetic zeolite was measured to be 23.773 emu/g. The magnetic recovery rate reached 99.2%, which facilitated magnetic separation of the sample after the adsorption process. The magnetic zeolite prepared in this study has potential application for the removal of Cs ions from wastewater.关键词：Magnetic zeolite;Cs ions;Adsorption
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发布时间：2021-12-10 - 摘要：Nylon 12 (PA12) was irradiated by an electron-beam in air. The structure and thermal properties of the samples with different absorbed doses were studied by mechanical testing, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The results showed that the elongation at break of PA12 decreased gradually with increasing absorbed doses, approaching 0% at an absorbed dose of 1 600 kGy, at which the tensile strength was 42 MPa. The whiteness of PA12 decreased with increasing absorbed doses. FTIR spectra showed that the carbonyl index and N-H bend strength of PA12 increased with absorbed doses. DSC results showed that the crystallization enthalpy and melting point of PA12 decreased gradually with increasing absorbed doses. XRD results showed that electron-beam irradiation did not change the crystal structure of PA12.关键词：Nylon 12;Electron-beam irradiation;Structure;Thermal properties
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发布时间：2021-12-10
RADIATION CHEMISTRY
- 摘要：The effect of electron-beam irradiation on the colority of the wastewater extracted by different methods in traditional physicochemical-biochemical processes was studied. Moreover, spectrophotometry was employed to determine the water colority of printing-dyeing wastewater. The results showed that the colority of the physicochemical-biochemical-treated wastewater was less than 10 Hazen at 200 kGy with up to 90% decolorization rate and that it was difficult to distinguish from pure water. For the physicochemical-treated wastewater, the decolorization rate was 46% at 100 kGy and the colority was about 50 Hazen at 200 kGy with up to 82% decolorization rate. Electron-beam irradiation had a positive effect on different kinds of dyeing wastewater. A combined treatment of electron-beam irradiation and a traditional physicochemical-biochemical process is recommended for the advanced treatment of dyeing wastewater.关键词：Electron-beam irradiation;Physicochemical treatment;Biochemical treatment;Colority;Printing-dyeing wastewater
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发布时间：2021-12-10
RADIATION TECHNOLOGY APPLICATION
- 摘要：People working in a radiation environment are at risk of radiation exposure. To minimize radiation hazards, an improved A* algorithm-guided path-planning method for radioactive environments is proposed. The method considers the radiation dose rate, obstacles, and shortest path constraint conditions and uses the cumulative dose as the actual cost and the estimated dose as the estimated cost to determine the optimal path. In the same radiation environment, the path length and total dose cost obtained by the improved A* algorithm are 29.3 m and 1.0 mSv, respectively, whereas that obtained via the traditional A* algorithm are 24.1 m and 28.8 mSv, respectively. Simulation results demonstrate that the path guided by the improved A* algorithm is safer and more reliable, and it can be applied to path planning in a nuclear radiation environment.关键词：Path planning;A* algorithm;Radiation environment;Visualization;Cumulative dose
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发布时间：2021-12-10
RADIATION PROTECTION
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