最新刊期
期 4 ， 2017
- 摘要：A novel poly-(acrylamide-co-vinyl-12-crown-4-ether) (PAM-12C4) hydrogel with a specific lithium-ion-response was synthesized via radiation-induced copolymerization and cross linking. The resultant PAM-12C4 was characterized by gel fraction, micro-FTIR spectroscopy, and thermo gravimetric analysis (TGA). The swelling behavior of PAM-12C4 in a lithium salt solution was also studied. The results showed that the PAM-12C4 hydrogel was successfully synthesized with a gel fraction of 94% at a dose of 10 kGy. The resultant PAM-12C4 hydrogel exhibits good thermal stability and gives an obvious response to the lithium-ion in an aqueous solution.关键词：Radiation copolymerization;Crown ether hydrogels;Lithium;Ion-response
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发布时间：2021-12-10 - 摘要：The ultra-high molecular weight polyethylene/modified illite-smectite interstratified clay minerals composites (UHMWPE/M-ISIC) prepared by melt blending were irradiated by γ-rays with a dose of 75 kGy in air and N2 atmosphere, respectively. The results showed that the tensile strength of UHMWPE/M-ISIC increased at first and then decreased with the increasing content of M-ISIC, and reached its maximum value within mass percent of 1% of M-ISIC. The thermal stability of UHMWPE after irradiation in air decreased significantly, while that of UHMWPE/M-ISIC decreased slightly. The thermal stabilities of neither material showed obvious changes after irradiation in N2 atmosphere. The crystallinity of UHMWPE after irradiation in air increased significantly, but decreased in N2 atmosphere, while that of UHMWPE/M-ISIC decreased after irradiation in both air and N2 atmosphere. The gel content and creep resistance of UHMWPE/M-ISIC after irradiation in air were higher than those of UHMWPE, and lower in N2 atmosphere. The results indicate that the M-ISIC irradiated in air could reduce the cracking by decreasing the diffusion rate of oxygen and thus promote the crosslinking effect. However, the crosslinking is hindered in N2 atmosphere as the free activity of the molecular chain is hindered.关键词：Illite-smectite interstratified clay minerals;UHMWPE (Ultra-high molecular weight polyethylene);Composites;Tensile-property;Thermal stability;Irradiation
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发布时间：2021-12-10 - 摘要：The effect of γ-radiation (60Co γ-ray source) on polydimethylsiloxane (PDMS) rubber soaked in 6% hydrogen peroxide solution was investigated at room temperature. The mechanical properties of the virgin and irradiated PDMS were compared in terms of their tensile strength and the variations in their chemical structure. These properties were analyzed by differential scanning calorimetry (DSC), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, and solvent swelling experiments. It was found that when PDMS was irradiated in 6% H2O2 solution, cross-linking reactions were predominant. Compared with the samples irradiated in air, PDMS irradiated in 6% H2O2 solution had a higher elongation at break and a lower elastic modulus, which suggested a lower cross-linking density. This may be attributed to the hydroxyl radicals generated from H2O2 during irradiation process, which capture the free radicals generated from PDMS and reduce the probability of the cross-linking reaction. The ATR-FTIR results showed that slight oxidation reactions occurred upon irradiation and the degree of surface oxidation of PDMS irradiated in 6% H2O2 does not significantly enhanced compared with the samples irradiated in air.关键词：Polydimethylsiloxane;γ-radiation effects;Hydrogen peroxide solution
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发布时间：2021-12-10 - 摘要：Amidoximated nylon 66 fibers were successfully synthesized by combining radiation-induced graft polymerization with chemical modification through a three-step approach. The chemical structure and micromorphology of the pristine and modified nylon 66 fibers were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that amidoxime groups were covalently connected to nylon 66 fibers. The results of adsorption of uranium in simulated nuclear industry effluents showed that amidoximated nylon 66 fibers performed a high adsorption efficiency (91.3%) and excellent selectivity for uranium adsorption, indicating that amidoximated nylon 66 fibers have potential application in industry.关键词：Radiation-induced graft polymerization;Nylon 66 fibers;Amidoximation;Adsorption;Uranium;Simulated nuclear industry effluents
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发布时间：2021-12-10
RADIATION CHEMISTRY
- 摘要：Forty cases undergoing RapidArc treatment were selected and grouped equally into head neck group, chest group, abdominal group, and pelvic cavity group. The raw cone-beam computed tomography (CBCT) projections produced in position verification were exported and then scatter-corrected by a self-developed cone-beam CT imaging toolkit (CITK) tool and reconstructed to be 5 mm thick tomographic files, which were then matched with the planning CT to map out the target area by eclipse with all the contour line saved. The radiotherapy of the planning CT and modified CBCT was designed with the same prescription dose, and the optimized conditions, and dose volume histogram (DVH) diagrams were generated and exported through dose calculation by Hounsfield unit-electron density (HU-ED) calibration curves. Finally, the dose distribution index (DDI) values for forty tumor patients were calculated and a t-test was used in the quantitative analysis to discuss whether statistics differences existed between the two methods. Statistical differences between the two methods in the four groups were found in the chest group (t=2.284, p < 0.05), while no statistical differences existed (p > 0.05) in all the other measurements. The comparative analysis showed that the effectively-corrected CBCT image and the corresponding calibrated HU-ED curves can be used in the dose calculation of tumor radiotherapy planning.关键词：CBCT (Cone-beam computed tomography);Radiotherapy planning;Dose calculation
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发布时间：2021-12-10 - 摘要：The foci of phosphorylated histone H2AX (γH2AX) and phosphorylated ataxia telangiectasia mutated (pATM) were visualized using immunocytochemical methods. Flow cytometry was used to assay γH2AX and pATM expression and the cell cycle. The results of immunocytochemical assay showed that the strongest induction of γH2AX and pATM foci appeared at 0.5 h and 4 h after irradiation, and the positivity for γH2AX and pATM foci reached 100% at 24 h with X-ray exposure in higher-dose groups. Flow cytometry results showed that the expression of γH2AX and pATM was related to the cell cycle. The rise of γH2AX and pATM expression was shown in each phase at 0.5 h and 4 h post-exposure, and this increase was more obvious in G0/G1 phase. At 24 h post-exposure, the expression of γH2AX and pATM decreased in G0/G1 and S phase, while increased significantly in G2/M phase. There was significant prevalence of the arrest at the G2–M transition among M059K cells. The above results indicate that the signaling pathways of γH2AX and pATM is involved in X-ray-induced double-strand breaks in M059K cells.关键词：X-ray irradiation;M059K;DNA double-strand break;γH2AX;pATM
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发布时间：2021-12-10 - 摘要：A 30-day survival rate experiment was carried out, and the assays of peripheral blood leukocytes, bone marrow DNA content, colony forming units of the spleen (CFU-S), and organ index parameters were analyzed to evaluate the protective effect of a nitric oxide-specific scavenger, Fe2+-diethyldithiocarbamate complex (Fe(DETC)2), on radiation-injured mice. The results showed that compared with the irradiation group, the 30 d survival rate, peripheral blood leukocytes, bone marrow DNA content, CFU-S, and organ index were significantly different from those in the mice treated with different doses. In particular, DETC was administered intraperitoneally at a dose of 300 mg/kg, which increased the survival rate by about 43%, and changes in the number of white blood cells, bone marrow DNA content, and CFU-S were statistically significant (p < 0.01). It is suggested that Fe(DETC)2, a nitric oxide scavenger, has a protective effect on radiation-injured mice.关键词：Nitric oxide scavenger;Fe(DETC)2;Radiation protection
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发布时间：2021-12-10
RADIBIOLOGY AND RADIOMEDICINE
- 摘要：The toxicity of uranium to various vital organs such as the lung, kidney, bone, and genitals was analyzed, and the research progress of uranium mobilization agents such as diethylenetriaminepentaacetic acid, catechol, chitosan, and related derivatives, was summarized. The purpose of this study is to promote the use of chelating agents to enhance their detoxification capacity and reduce the side effects.关键词：Uranium;Chelating agents;Review
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发布时间：2021-12-10 - 摘要：The effects of ionizing radiation on biological characteristics of the cell membrane, membrane lipids, membrane proteins, and cell membrane signal transduction were summarized. In the future, the mechanisms of cancer-cell apoptosis induced by ionizing radiation and the effects on mitochondria and other organelles may be the important directions for the study on biological effects of ionizing radiation.关键词：Ionizing radiation;Cell membrane;Membrane lipids and proteins;Signal transduction;Review
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发布时间：2021-12-10 - 摘要：Progress in the assembly of nanoparticles with DNA origami is summarized, with an emphasis on surface plasmon resonance using DNA origami-assembled nanostructures, including surface fluorescence enhancement, and surface-enhanced Raman scattering. Future perspectives for the development of surface plasmon resonance with DNA origami are proposed.关键词：Surface plasmon resonance;DNA origami;Nanoparticles;Fluorescence enhancement;Surface-enhanced Raman scattering (SERS);Review
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发布时间：2021-12-10
REVIEW
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