最新刊期
期 1 ， 2017
- 摘要：6-(4-(dimethylamine) pyridine) methyl coumarin with antitumor and radio sensitizing effect on A549 cells was synthesized through brominating and electrophonic reactions. The inhibition rate for A549 cells, the radio sensitizing effect, and the reactive oxygen species (ROS) volume were measured by MTT assay, clone formation assay (radio sensitizing effect (RSE) was calculated by the multitarget single hit model) and DCFH-DA method, respectively. The results showed that the inhibition rate for A549 cells was positive related to the drug concentration, and the survival fraction of combination group (radiation plus administration drug group) decreased significantly compared with radiation group (p < 0.05), RSE=1.585, the ROS volume of combination group increased significantly compared with radiation group (p < 0.05) under various doses. The results indicate that 6-(4-(dimethylamine) pyridine) methyl coumarin can inhibit A549 cells and the inhibition effect increase with the drug dose, and has radio sensitizing effect on A549 cells, and can increase the ROS volume in A549 cells significantly.关键词：6-(4-(dimethylamine) pyridine) methyl coumarin;Radiosensitization;A549 cells
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发布时间：2021-12-10 - 摘要：Twenty-four male SD rats were randomly assigned to 4 groups:sham-exposure group, 0.2 W/kg exposure group, 0.5 W/kg exposure group, and 1.5 W/kg exposure group. The exposure groups were exposed to 1.84 GHz, with SAR (Specific absorption rate) of 0.2, 0.5, 1.5 W/kg for 2 weeks of 5 d/week and 30 min/d. Immediately after the last exposure, SD rats were anesthetized and executed, and then cerebral cortex and hippocampus were collected. Chemical colorimetry assay was used to detect the levels of cholinergic neuronal markers, the activity of antioxidant enzymes and the products induced by oxidative stress in cerebral cortex and hippocampus. The results showed that compared with that in the sham-exposure group, the ACh and ChAT level of rat cerebral cortex decreased significantly in 1.5 W/kg exposure group (p < 0.05); the AChE level of rat cerebral cortex didn't show any obvious difference in exposure groups; the activity of SOD, GPX, CAT and MDA contents didn't change significantly in exposure groups; the level of cholinergic neuronal markers, the activity of antioxidant enzymes and the products induced by oxidative stress in hippocampus didn't have any significant difference in the exposure groups. The results indicate that under the present experimental setting, radiation does not cause brain damage induced by oxidative stress, and some cholinergic neuronal markers level in the cerebral cortex of SD rat decrease in 1.5 W/kg exposure group.关键词：Radiation-frequency electromagnetic radiation;SD rat;Cholinergic neuronal markers;Antioxidative damage;Brain tissue
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发布时间：2021-12-10 -
Effect of wide-band electromagnetic pulses on the reproductive system of rat and subsequent recovery
摘要：The testosterone, superoxide dismutase (SOD), malondialdehyde (MDA), and acrosin activity were measured by ELISA. The cell apoptosis of testicular was observed by TUNEL. The sperm motility was analyzed by CASA. The results showed that the harms caused by W-EMP exposure, and the subsequent recovery were dependent on the intensity and pulse number of W-EMP. With the increase of electric intensity and pulse number the impact of W-EMP exposure increased, which leaded to a slower recovery rate. The results indicates that compared with the pulse number, the electric intensity in present work has much stronger impact on the reproductive system.关键词：Wide-band electromagnetic pulse;Reproductive system;Sperm motility;Serum testosterone;Acrosin- 9
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发布时间：2021-12-10 - 摘要：Dose distribution index (DDI) for fifty chest tumor patients were retrospectively evaluated. The patients were divided into three groups depending on tumor location, including the conventional group, the group with lesion close to the sensitive tissues to be protected, and the chest wall group. For each patient, three tentative plans were designed and recorded during planning, one of which was eventually selected for treatment. When planning target coverage and organs at risk sparing are considered as equally important, the tentative plan with the highest DDI score is shown to coincide with that actually delivered in 35 of the 50 patients considered (70.0%). In 13 of the remaining 15 cases (86.7%), the plan with highest DDI value still coincides with that actually selected, provided that some organs at risk sparing or target coverage is given higher priority than others. DDI provides a non-subjective tool for dosimetric comparison of tentative radiotherapy plans. In particular, DDI readily quantifies differences among competing plans with similar-looking dose-volume histograms and can be easily implemented. It provides a reliable basis to select the best among the tentative radiotherapy plans.关键词：Dose distribution index (DDI);Chest tumor;Feasibility analysis;Radiotherapy plan
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发布时间：2021-12-10
RADIOBIOLOGY AND RADIOMEDICINE
- 摘要：The layered chitosan hydrogels were prepared by a two-step method of low temperature irradiation and freeze/thaw cycle. The poly (vinyl alcohol)/poly (ethylene oxide) (PVA/PEO) was the basic layer and the poly (vinyl alcohol)/chitosan (PVA/CS) was the second layer with antibacterial property. The best preparation technology was selected by the research of absorbed dosage, electron-beam current and concentration of polymer solution. And the structure and properties of the layered hydrogel were characterized by FTIR and SEM, swelling test, mechanical test and antibacterial test. The results showed that the layered hydrogel prepared by this method had an obvious layered structure and closely interlayer combination, there was no significant structural changes. The swelling property increased gradually with the increasing of chitosan content, and the equilibrium swelling degree of 60% CS reached 2 200%. The mechanical strength of layered hydrogel increased firstly and then decreased with the increasing content of chitosan. The tensile strength of layered chitosan with 40% CS increased from 0.35 MPa of PVA/PEO hydrogel to 0.47 MPa. The antibacterial test showed that the layered hydrogels had obviously antibacterial effects on Escherichia coli and staphylococcus, and the antibacterial effects increased with the increasing content of chitosan.关键词：Layered hydrogel;Low temperature irradiation;Chitosan;Antibacterial property;Mechanical strength
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发布时间：2021-12-10 - 摘要：Interaction systems of electron beam irradiation and sensitizers were used to degrade wet chitosan powder for preparing chitosan with low molecular weight and well biological activity. The degraded molecular weight of the sample was characterized by gel permeation chromatography (GPC), and chemical characteristics including main chain structure and crystallization were determined by Fourier transform infrared spectroscopy (FTIR) and X ray diffraction (XRD), respectively. The experimental results showed that no obvious change generates in the main chain structure of the degraded chitosan, and the crystallization increased with the decreasing molecular weight. With the presence of sensitizers, the degraded molecular chitosan can be decreased from 1.1×105 to 1 170 at low absorbed dose of 20 kGy with higher rates of 1.51×10-5.关键词：Chitosan;Irradiation degradation;Sensitizer;Molecular weight
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发布时间：2021-12-10 - 摘要：Based on tea pigment dyeing process with mordant of wool fabric, screening of the dyeing processes with different metal mordants were carried out, and dyeing properties of wool fabric before and after ultraviolet radiation were compared. The results showed that K/S value and dye fixation of wool fabric dyed by tea pigment dyeing process with CuSO4 were higher than that in other processes, and improving dyeing properties of wool fabric treated by ultraviolet radiation was confirmed according to the comparison of experimental data. Therefore, the ultraviolet radiation was combined with tea pigment dyeing process with CuSO4 to improve the tea pigment dyeing effects of wool fabric. The tea pigment dyeing process with CuSO4 of wool fabric treated by ultraviolet radiation was discussed during single factor analysis, these optimized scopes of ultraviolet radiation time, CuSO4 content and dyeing time were selected, then the process was optimized by using the three-factor quadratic general rotary unitized design. The optimum process was determined as follows (dosage/on weight of fabric (o.w.f)):ultraviolet radiation time 9 min, tea pigment 5.0%, CuSO4 1.7%, HCOOH 2.0%, pH=3.5~4.0, 95℃, dyeing time 60 min, bath ratio 1:50. Compared with conventional tea pigment after chrome process, the dyeing effects of wool fabric dyed by the optimum process, which possessed of lower metal mordant content, were better.关键词：Ultraviolet radiation;Wool fabric;Tea pigment;Metal mordant;Dyeing process with mordant;Optimization
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发布时间：2021-12-10
RADIATION CHEMISTRY
- 摘要：12C6+ ion beam was used to irradiate strains of Lactobacillus plantarum JTL, and the results showed that the strain could get the highest positive mutation rate and lethality with 34.4% and 80% at the optimal absorbed dose of 300 Gy. The strains which could produce higher lactic acid were screened by selective MRS mediums and fermentation experiments. Finally, three mutations JTL2, JTL3 and JTL5 were obtained through the two screening steps of selecting plate and fermentation, and the contents of lactic acid in this three fermentation broth were greater than the original strain by 41.29% to 49.64%. The pass-generation test indicated that the heredity character of these mutations were stable. It is demonstrated that the lactic acids produced by Lactobacillus plantarum JTL were remarkably improved, and heavy ion beam is an efficient radiation resource for microorganism breeding.关键词：Lactobacillus plantarum;Heavy ion beam;Irradiation;Mutation breeding
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发布时间：2021-12-10
RADIATION TECHNOLOGY APPLICATION
- 摘要：For the sake of evaluating the feasibility of dose rate switching technique, systematic numerical simulations on the MIS (Metal insulator semiconductor) structure was done based on a quantitative physical model and the experimental conditions of dose rate switching technique, regarding hydrogen concentration, initial defect concentrations and temperature as variables. It turned out that the feasibility of the dose rate switching technique is strongly dependent on the hydrogen concentration and initial defects concentrations in the oxide layer of the bipolar devices. Therefore, the experiments of dose rate switching technique have possible failures on part of devices and circuits.关键词：Dose rate switching;Acceleration methods;Numerical simulation;Hydrogen concentration;Initial defect concentrations
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发布时间：2021-12-10
RADIATION INTERDISCIPLINARY RESEARCH
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