The effects of neutron and gamma radiation on shielding materials directly influence the safety of nuclear facilities. In this study, a B₄C/epoxy resin shielding material was fabricated. The mechanical properties, fracture microstructural morphology, characteristic groups, and thermal degradation of the shielding material under two different irradiation conditions, 1 MGy gamma and superimposed 1.19×10¹⁵ cm^-2 neutron radiation, were compared. After gamma irradiation for 11.6 d and superimposed neutron irradiation for 3 h, the mechanical properties of the shielding material continued to decrease; however, they did not decrease to 50% of those before irradiation, and radiation degradation occurred instead of material failure. Compared with separate gamma irradiation, the peak intensity in the ¹H-NMR spectra of the shielding material near δ=7 did not change significantly after the additional neutron irradiation, indicating that there was no further degradation of the C?H bond on the benzene ring. At 50% loss in mass, the temperature decreased from 526.3 °C before irradiation to 453.2 °C after gamma irradiation and 463.9 °C after gamma superimposed neutron irradiation, demonstrating the decrease in thermal stability.

CS-g-PAM/AMPS superabsorbent resin was prepared by graft copolymerization of chitosan (CS), acrylamide (AM), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) by microwave radiation. The structure and morphology of the superabsorbent resin were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The mechanism of the reaction was also examined. The thermal decomposition process of resin in a nitrogen atmosphere was studied using thermogravimetric analysis. The absorption capacity of the resin in different concentrations of salt solution and the swelling kinetics of the resin were also discussed. The results showed that the resin with a uniform three-dimensional network was synthesized. When the mass fraction of CS was 10%, the resin showed the highest water absorption of 1 332 g/g. The absorption capacity of the superabsorbent resin decreased with the increasing concentrations of inorganic salt solution and metal valence state. The corresponding kinetic parameters, such as the activation energy (E), pre-exponential factor (A), and reaction order (n), were obtained according to the Kissinger and Crane methods. The values of E, A, and n were approximately 223.65 kJ/mol, 3.6×10¹⁷ s^?1, and 2.14, respectively. The swelling process of the resin satisfied the pseudo-second-order kinetic model, and the diffusion in aqueous solution conformed to the non-Fickian diffusion process.

Bisphenol A epoxy resin was irradiated in air by a 1.5 MeV electron beam accelerator at dose rates of 18 kGy/h and 2 250 kGy/h to achieve the total absorbed doses of 135 kGy, 270 kGy, 500 kGy, and 1 000 kGy. The effects of the dose rates and the absorbed doses on the surface morphology, chemical structure, and thermal properties of the epoxy resin were systematically investigated. The results showed that high dose rates induced vein-like cracks in the epoxy resin, while the total absorbed dose significantly affected the thermal stability and mechanical properties of the resin. Moreover, the epoxy resin exhibited a radiation cross-linking tendency at low absorbed doses, while radiation degradation dominated at high doses. An electron spin resonance analysis indicated that the free radical signals generated during the irradiation were from alkyl radicals and peroxy radicals. The concentration of free radicals was positively correlated with the absorbed dose. Furthermore, the stability of the free radicals in air was studied. The concentration of the generated free radicals reached a plateau at longer storage times.

Using a high-energy electron beam to study the influence of different absorbed doses on the structure and performance of dimeric acid polyamide. Fourier infrared spectroscopy confirmed that the C=C bond participated in the crosslinking reaction during the radiation process. With a increase in the absorbed doses, the softening point, gel content, rotational viscosity, and differential scanning calorimetry (DSC) melting peak T_m increased significantly,while the data of DSC melting enthalpy ΔH_m declined slightly. According to the results of rheological data, as the absorbed doses increases, the viscosity η and the corresponding temperature T_j of the intersection of G' and G" increasing significantly, viscosity η and T_j were (195±5) Pa·s and 118.2 ℃, respectively, without the treatment of electron beam treatment. These values increased to (1 500±50) Pa·s and 144.7 ℃, respectively, with an absorbed dose of 120 kGy.

Two herbal formulas were prepared by combining extracts from Angelica sinensis, Cistanche deserticola, Paeonia lactiflora pall, Fructus sophorae, and Astragalus and assessed for radioprotective efficacy. Fifty-six healthy C57BL/6J mice were γ irradiated at a dose of 4 Gy to establish a radiation injury model. These mice were randomly divided into four groups with equal numbers of males and females: a radiated vehicle control group, a commercial radioprotective extract control group (Hemo-1#), and two experimental groups (Exp-2# and Exp-3#). The vehicle control group was administered an equal volume of distilled water. The other groups were administered different herbal formulas. Body weight and conventional indicators of peripheral blood homeostasis were recorded before and after irradiation. On the first day after irradiation, mice fed herbal extracts experienced a smaller decrease in leukocyte and lymphocyte counts than untreated mice. At 7 days after irradiation, mouse leukocyte, erythrocyte, platelet, and lymphocyte counts displayed slow recovery. The two groups receiving different herbal formulas showed a similar radioprotective effect on body weight and peripheral blood test results than the Hemo-1# group. Our experimental herbal formulas showed radioprotective effects against γ ray-induced damage.

In order to accurately evaluate the safety of electromagnetic exposure generated by wireless charging of pacemakers, the modeling constructions and simulation calculations were performed by the finite element simulation software COMSOL. Firstly, the models of human brain tissue, a simple thorax and heart were constructed. The distributions of magnetic induction intensity ( B ), induced electric field intensity ( E ), as well as the distribution of SAR values in human head tissue generated in those three parts were obtained. In the calculations, the operating frequency of the wireless charging system was set to 251 kHz. Simulation results showed that maximum B value in human head model was 0.337 μT, accounting for 9.26% of ICNIRP threshold, the maximum E value was 0.393 V/m, accounting for 0.45% of ICNIRP threshold. In human heart model, the maximum B value was 3.118 μT, accounting for 85.01% of ICNIRP threshold, the maximum E value was 0.278 V/m, accounting for 0.32% of ICNIRP threshold. And in human brain tissue, SAR value was 3.009×10^-7 W/kg, which was much lower than the recommended value of public electromagnetic exposure established by ICNIRP. This indicates that the wireless charging process of the pacemaker will not pose a health risk to users.

In this study, we explored the effects and principles of light-emitting diodes (LEDs) in preventing acute radiodermatitis (RD) in breast cancer patients. Twenty patients with breast cancer, who met the inclusion and exclusion criteria and had undergone modified radical mastectomy, were selected and administered standard preventive radiotherapy. Fifteen days after the first radiotherapy dose, the patients were randomly divided into a control group and an experimental group and subjected to additional LED exposure. Twenty-one days after LED illumination, the preventive effect of LED on RD was evaluated by statistically analyzing the RD scores of the two groups. The preventive effects were inferred by histological and gene expression analyses. The results showed that compared with the control group, the RD score of the experimental group did not change significantly, so that the prevention effect of LED was significant. Our results showed that LED exposure increased skin appendage (p=0.041), accelerated microvascular growth (p=0.007), and increased IL-10 and MMP-9 expression (p<0.005). Thus, LED exposure may have important clinical significance in treating breast cancer patients.

To evaluate the clinical applicability of deep learning based auto-segmentation of organs at risk (OARs) based on geometric and dosimetric indices. In this study, a total of 35 patients with rectal cancer who received radiotherapy in the Fudan University Shanghai Cancer Center were enrolled, and an in-house developed deep learning system was used to automatically segment OARs. Taking manual delineation as reference, the geometric evaluation indices included the dice similarity coefficient (DSC), jaccard similarity coefficient (JSC), hausdorff distance (HD), and mean distance to agreement (MDA). For each case, the treatment planning was optimized based on the auto-segmented OARs. The plan optimization and evaluation process was consistent with clinical procedure, recorded as Plan_FD. The dosimetric differences between Plan_FD and the original clinical treatment plan (recorded as Plan_Treat) were compared through dose-volume parameters and three-dimensional gamma analysis. The auto-segmented and manually delineated OARs were not only highly overlapping in three-dimensional space with an average value of DSC greater than 0.85 but also well matched in edge details with an average value of MDA less than 2.8 mm. In the dosimetric evaluation, a statistically significant difference was observed only for the bladder (p < 0.05); the dose-volume parameters of the other OARs and PTV were not statistically significant. Three-dimensional γ analysis (3 mm / 3 % standard) was performed on Plan_FD and Plan_Treat, where the percentage of points with γ ≤ 1.0 was (91.63 ± 6.27) %. Deep learning-based auto-segmentation of OARs has a high geometric similarity with manual delineation. The auto-segmented OARs have no significant impact on treatment planning and dose distribution, and have the potential to be directly applied to clinical treatment planning.

The antimicrobial agent 3-(acrylamidopropyl)trimethylammonium chloride (APTAC) was grafted onto vacuum plasma?treated denim fabrics. Optimal treatment conditions, including sputter-gas species, gas pressure, power, and duration were investigated using Orthogonal Array Testing Strategy (OATS) analysis. The obtained denim fabrics were characterized using energy dispersive X-ray (EDS)，Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Strength, tactile quality, air permeability, and antibacterial properties of the denim fabric before and after grafting were characterized. The results showed that APTAC was successfully grafted onto the denim fabric under conditions using an argon/oxygen mixture as sputtering gas, a sputtering flow ratio of 50:50, a vacuum plasma discharge power of 500 W, and a treatment time of 5 min without affecting the fabric’s air permeability or mechanical properties. Antibacterial efficacy tests showed that APTAC-treated cotton fabric inactivated 92.8% of S. aureus and 94.87% of E. coli O157:H7 in 30 min contact time, thereby achieving sound antimicrobial activity.

The effect of 5-MeV electron accelerator irradiation of 400 kGy on the formic acid cycling separation of cellulose, lignin, and xylose from Triarrhena lutarioriparia (TL) were studied, and the enzymatic conversion rate and structural characteristics of TL cellulose were analyzed. For 400 kGy irradiated TL, the results revealed that the average purity of cellulose was 81.13% and the recovery of lignin and xylose were 28.68% and 10.16%, respectively, which were higher than those of the unirradiated sample. The recovery of cellulose, concentration of xylose, and purity of lignin increased with the increase in cycle times. The final concentration of xylose for pre- and post-irradiated TL were 31.35 mg/mL and 37.35 mg/mL, respectively, and the purity of lignin was more than 90%. Fourier transform infrared and X-ray diffraction results revealed that TL cellulose separated by formic acid were formylated and exhibited high crystallinity. The enzymatic conversion rate of TL cellulose was 54.30%–57.47% after hydrolysis for 120 h, this rate was considerably higher than that of TL. These results indicated that the formic acid recycling fractionation process could effectively separate TL lignocellulosic components, which could support its large-scale utilization.

Uranium enrichment by Deinococcus radiodurans under different times, bacterial doses, initial uranium concentrations, solution pH values, and pH-adjusted uranium solutions was explored, and the enrichment mechanism was elucidated by Fourier transmission infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optimal conditions for adsorption included an enrichment time of 60 min, bacterial dose (i.e., the volume of bacterial liquid corresponding to an OD₆₀₀ of 1) of 10 mL, initial uranium concentration of 30 mg/L, and solution pH of 5.0. The solution pH increased slightly after enrichment with uranium solutions of different pH. FTIR and SEM analyses revealed several changes in active functional groups and bacterial characteristics before and after enrichment. Deinococcus radiodurans has good enrichment performance for low uranium solution, and it regulated the pH of the uranium solution and increased the pH of the adsorbed uranium solution.

Based on the spectrum distribution of typical broadband electromagnetic pulses, we constructed a dispersive electromagnetic model rat with fine tissue and organ structure and calculated the internal electric field distribution in rats irradiated by two broadband electromagnetic pulses. The results showed that the field strength in the irradiated rats was highly dependent on the distribution of tissues. Different waveforms produced different electric field distributions in the body. The width of the pulse that penetrated the body was greatly narrowed. Furthermore, the low-frequency energy of the pulse at 10 kHz~1 MHz was markedly reduced. The peak field strength of the important tissues and organs of the irradiated rats was approximately 1% of the spatial peak field strength. The data provide a theoretical quantitative basis for establishment of the dose-effect relationship of pulsed biological effects. The data will also serve as a reference for simulation calculation of the effect of broadband electromagnetic pulses in living organisms.

Low-energy electron beam is an advanced technology that is widely used for manufacturing various high-tech products in the United States, Japan and developed countries in Europe since the 1980s. Owing to the high price of imported electron beam equipment and related processes and raw materials, the promotion of low-energy electron beam technology in China is restricted. In recent years, with the rapid progress in the domestic independent research and development of low-energy electron beam equipment technology, the entry threshold of the downstream industry has been reduced; research conducted by domestic enterprises on new materials, new technologies, and new processes has been extensively promoted, and the bottleneck of industrial development has been broken. Lowenergy electron beam and its application usher in rapid development.