最新刊期
卷 42 ， 期 4 ， 2024
- “在血液系统疾病治疗领域，全身放疗技术取得新进展。专家结合临床实践，综述了长距离固定野照射、容积旋转调强和分段照射等实现方式的技术特点，为造血干细胞移植预处理提供解决方案。”摘要：Total body irradiation (TBI) is a technique that irradiates the entire body of the patient. It serves as a conditioning regimen prior to hematopoietic stem cell transplantation for hematological diseases. Its primary functions include killing residual tumor cells, immunosuppression, and creating space in the bone marrow for hematopoietic stem cell transplantation. Currently, the main methods of implementing TBI include extended distance fixed field irradiation, volumetric modulated arc therapy (VMAT-TBI), and segmented irradiation. In this paper, based on our clinical experience, we review the technical characteristics and relevant research progress of these three methods.关键词：Total body irradiation;Hematopoietic stem cell transplantation;Conditioning regimen
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发布时间：2024-08-26
REVIEW
- “最新研究发现，通过原位辐射还原法合成的硫化镉量子点（CdS QDs）与聚醋酸乙烯酯（PVAc）结合形成的凝胶指纹膜，可在紫外线照射下清晰显现指纹纹路，为刑事侦查提供有效手段。”摘要：Fingerprints are an important trace material evidence for police to identify criminal. Cadmium sulfide quantum dots (CdS QDs) are fluorescent-labeled nanomaterials that can be used to improve the clarity and resolution of fingerprints. In this study, thioglycollic acid (TGA) was successfully modified to CdS QDs using the in-situ radiation reduction method, and synthetic TGA-CdS QDs were combined with polyvinyl acetate (PVAc) to form a TGA-CdS QDs/PVAc gel fingerprint film for fingerprint development. The structure and properties of the TGA-CdS QDs were characterized and tested using Fourier transform infrared (FTIR) spectroscopy, fluorescence spectrum, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effects of temperature, concentration of TGA-CdS QDs, pH, and mass fraction of the PVAc gel fingerprint film on fingerprint development were investigated. The results showed that a combination of 6 mg/mL TGA-CdS QDs solution with 20% PVAc gel fingerprint film at room temperature (25 ℃) and pH of 9.0 resulted in the clearest, most complete, and high-resolution fingerprint patterns of fluorescence display. The carboxylic acid group formed by TGA-CdS QDs in an alkaline solution completely combined with the amino acids, proteins, fats, urea, and other components of the fingerprint residue attached to the PVAc gel film. Under ultraviolet irradiation, the fingerprint lines were clearly displayed in the form of fluorescence. The fingerprint display method can be effectively used in criminal investigation.关键词：Radiation;Quantum dots;PVAc gel;Fingerprint film;Display performance
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发布时间：2024-08-26 - “在核医学、航空和航天领域，一项提升硅橡胶耐辐射性能的研究取得突破。通过添加无定型硼粉，显著增强了硅橡胶的热稳定性和抗辐射损伤能力，为开发新型耐辐射高分子材料提供了有效策略。”摘要：In cutting-edge fields such as nuclear medicine, aviation, and aerospace, polymer materials face severe challenges owing to long-term exposure to extreme radiation environments. These environments impose stringent requirements on the service reliability of materials, which makes it imperative to improve the radiation resistance and aging resistance of polymer materials. To this end, amorphous boron powder (B) was used to prepare amorphous boron powder/silicone rubber (B/SR) composites because of the possible radical-scavenging characteristics of the empty orbitals present on the outer layer of amorphous boron powder. The impact of B on the radiation resistance of silicone rubber was investigated through systematic studies on the changes in the mechanical, thermal, and crosslink density properties of the material before and after irradiation. The experimental findings demonstrated that, at an absorbed dose of 200 kGy, the retention rate of elongation at break of B/SR0.3 sample can be maintained at (49.4±3.1)%, whereas pure SR is only (24.7±2.7)%. The initial breakdown temperature of irradiated silicone rubber composites raised from 454.9 °C to 472.8 °C by adding 0.3 parts of B, which significantly enhanced its thermal stability in radiation environments. To visually demonstrate the changes in the internal radicals of the silicone rubber composite during irradiation, this study used a UV lamp-electron paramagnetic resonance (UV-EPR) spectrometer for real-time monitoring and revealed that B could effectively eliminate the free radicals generated in the silicone rubber composite during the irradiation process. This study provides an effective strategy to improve the radiation resistance of silicone rubber composites and lays a solid foundation for the development of novel radiation-resistant polymer materials.关键词：Silicone rubber;Radiation effects;Inorganic nanoparticles;Free radical scavenging
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发布时间：2024-08-26 - “最新研究揭示了低剂量电子束辐照对聚烯烃共混体系结构与性能的影响，为聚烯烃产品开发提供了新思路。”摘要：This study investigated the impact of low-dose electron beam irradiation on the structure-property correlation of linear low-density polyethylene (LLDPE), ternary copolymer polypropylene (co-PP), and their blends. Effects of the absorbed dose on the rheological properties, strength, crystallization behavior, crystal structure, and mechanical properties of LLDPE/co-PP blended polyolefins with various blending ratios were examined. The melt index test results indicate that, for LLDPE: co-PP ratios of 3∶1 and 1∶1, the melt index of each prepared polyolefin decreases and its crosslinking degree increases as the absorbed dose increases. However, for a LLDPE: co-PP ratio of 1∶3, the crosslinking degree of the polyolefin decreased with increasing absorbed dose. The crystal structure and crystallization behavior of the polyolefins were minimally affected by their absorbed doses, however, varying the ratios of blended LLDPE and co-PP affected the crystallization of both LLDPE and co-PP. For a blend with 1: 1 ratio, an absorbed dose greater than 2 kGy resulted in a sample elongation at break exceeding 890% and a fracture strength of 25.4 MPa those of both LLDPE and co-PP. Additionally, the stress-strain curves of the prepared polyolefins indicated that the absorbed dose enhanced the compatibility between LLDPE and co-PP. Thus, low-dose irradiation of LLDPE/co-PP polyolefins would offer a new avenue of research on polyolefin product development.关键词：Copolymer polypropylene;Linear low density polyethylene;Radiation modification;Low absorbed dose
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发布时间：2024-08-26 - “最新研究揭示了纳米氧化物@微晶纤维素基吸附剂在饮用水净化领域的突破，成功去除致癌物质三氯乙酸，为饮用水安全提供新解决方案。”摘要：Trichloroacetic acid is a common nonvolatile byproduct of drinking water disinfection and poses carcinogenic risks to the human body. In this study, four types of nano-oxide@microcrystalline-cellulose-based adsorbents (P25@microcrystalline cellulose, SiO₂@microcrystalline cellulose (MCC-g-GMA@SiO2), Fe3O4@microcrystalline cellulose, and Fe2O3@microcrystalline cellulose) were successfully prepared by the pre-radiation grafting-embedding method. Subsequently, their ability to remove trichloroacetic acid from drinking water was investigated. The micro zonation morphology and surface properties of the materials were characterized and tested using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), Thermogravimetric (TG) analysis, and Scanning electron microscopy (SEM) characterization methods. The effects of monomer concentration, embedding concentration, and absorbed dose on the weight gain rate were systematically investigated. A complete static adsorption equilibrium curve was obtained on the basis of the results of adsorption experiments of four buried nano-oxides. The performance of SiO2@microcrystalline cellulose was found to be significantly higher than that of the other three adsorbents. When the volum percentage of monomer concentration was 30%, the mass percentage of embedding concentration was 4%, and the absorbed dose was 60 kGy, the removal rate of trichloroacetic acid in drinking water reached 83.27%. This series of adsorbent materials present significant potential for practical application in drinking water purification.关键词：Microcrystalline cellulose;Glycidyl methacrylate;Trichloroacetic acid;Pre-radiation grafting;Embedding;Adsorption
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发布时间：2024-08-26 - “最新研究发现，通过辐射诱导接枝聚合技术在超高分子量聚乙烯纤维上引入胍基和偕胺肟基，成功制备了一种新型抗菌海水提铀材料。该材料具有出色的抗生物污损能力，能杀灭99.9%的大肠杆菌和金黄色葡萄球菌，同时在海水提铀中展现出快速吸附速率和高吸附容量，经过多次循环使用仍保持高效吸附和脱附性能，为海水提铀领域提供了一种具有广泛应用潜力的可重复使用材料。”摘要：Fiber absorbents are among the most economical materials for uranium extraction from seawater. Marine organisms are prone to fouling while being deployed in the sea, severely impairing the adsorption properties of the fiber. In this study, a novel antimicrobial adsorbent (UHMWPE-g-GEAO) was prepared by grafting guanidino and amidoxime groups onto ultra-high molecular weight polyethylene (UHMWPE) using radiation-induced graft polymerization technique. The guanidino groups endowed the fiber with excellent resistance to biofouling, enabling it to kill 99.9% of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). UHMWPE-g-GEAO fibers exhibited a fast uranium adsorption rate and high adsorption capacity, reaching 156.00 mg/g in aqueous solution and 1.39 mg/g in real seawater within 14 days. Additionally, the adsorbent exhibited superior reusability, preserving more than 94.5% of its adsorption efficiency and 96.2% of its desorption efficiency after five adsorption-desorption cycles. In this study, a reusable UHMWPE antimicrobial adsorbent fiber with promising potential for uranium extraction from seawater was developed.关键词：UHMWPE fiber;Amidoxime;Uranium extraction from seawater;Antimicrobial
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发布时间：2024-08-26
RADIATION CHEMISTRY
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Carbon ions inhibit non-small cell lung cancer cell proliferation by inducing mitochondrial damage AI导读
“在非小细胞肺癌治疗领域，研究团队通过A549细胞实验，发现碳离子照射能有效抑制肺癌细胞增殖。4 Gy剂量下，细胞增殖受到显著抑制，线粒体形态、膜电位发生改变，促凋亡蛋白释放，细胞凋亡率和线粒体自噬水平升高。清除线粒体后，碳离子失去促细胞凋亡作用。研究为肺癌治疗提供新思路。”摘要：We investigated the effects of mitochondrial damage via carbon ion irradiation on the proliferation of human non-small cell lung cancer (A549) cells by monitoring mitochondrial morphological changes, mitochondrial membrane potential transformation, release of membrane-associated proteins, and mitophagy. A549 cell proliferation and activity were monitored by CCK-8 and colony formation assays. Changes in mitochondrial morphology and mitochondrial membrane potential were detected by mitochondrial membrane-specific fluorescence staining. Expression of associated proteins was detected by western blot and real-time quantitative PCR. Annexin V-FITC and PI staining were used to detect cell apoptosis. Mitophagy was detected by immunofluorescence co-localization and western blot. The apoptosis rate of mitochondria-lacking A549 cells after carbon ion irradiation was also quantitated. Irradiation with carbon ions at dose of 4 Gy significantly depressed the proliferation capacity of A549 cells, and induced mitochondrial shrinkage and decreased mitochondrial membrane potential. Levels of mitochondrial membrane protein Bax/Bak, and intermembrane proteins Cyto-C and SMAC were elevated, with increased apoptosis and mitophagy. In cells depleted of mitochondria, carbon ion irradiation exerted no significant effect on A549 cell apoptosis. Carbon ion irradiation can inhibit A549 cell proliferation. The half maximal inhibitory exposure dose is 4 Gy. Carbon ions lose their anti-proliferative function in mitochondria-free A549 cells. In summary, carbon ion irradiation can decrease mitochondrial membrane potential and induce the release of pro-apoptotic proteins, thereby inhibiting A549 cell proliferation.关键词：Carbon ion irradiation;Mitochondrial damage;Mitophagy;Mitochondrial apoptosis- 42
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发布时间：2024-08-26
RADIOBIOLOGY AND RADIOMEDICINE
- “川芎挥发性成分研究取得新进展，专家采用电子鼻与GC-MS技术，发现10 kGy以下辐照不影响其主要挥发性成分。”摘要：Volatile components are one of the main active components of Ligusticum chuanxiong Hort and are important indicators for evaluating the medicinal quality of Ligusticum chuanxiong. To explore the effects of 60Co-γ irradiation on the volatile components of Ligusticum chuanxiong, the samples were treated with different irradiation doses, and the changes of the volatile components before and after irradiation were analyzed using an electronic nose combined with headspace solid-phase microextraction and gas chromatography-mass spectrometry. Principal component analysis (PCA), linear discriminant analysis (LDA), orthogonal partial least squares discriminant analysis (OPLS-DA), and cluster statistical analysis were used to elucidate changes in the volatile components of Ligusticum chuanxiong before and after irradiation. The electronic nose detection results and gas chromatography–mass spectrometry detection results indicated that ketone alkanes, alcohols, aldehydes, and ketones contributed to the odor of Ligusticum chuanxiong. Irradiation treatments at doses ≤10 kGy had no significant effect on the odor of Ligusticum chuanxiong. The results demonstrated that after irradiation at 0 kGy (control group), 3 kGy, 7 kGy, and 10 kGy, 60 compounds were identified in Ligusticum chuanxiong, including 23 hydrocarbons, 12 alcohols, 10 lipids, and 4 aldehydes or ketones, and 11 others. There were mainly 21 volatile substances that changed after irradiation, accounting for approximately 12.92% of the volatile components in Ligusticum chuanxiong; however, they were not the main volatile components of Ligusticum chuanxiong. No new compounds were identified in Ligusticum chuanxiong after irradiation treatment within a dose of 10 kGy. The results provide a theoretical basis and reference for the influence of 60Co-γ irradiation on the quality of Ligusticum chuanxiong samples and also lay a certain foundation for the application of irradiation in Ligusticum chuanxiong pieces and traditional Chinese medicine and simple preparation resources. The results indicate that the treatment of 60Co-γ irradiation on the Ligusticum chuanxiong samples with doses ˂10 kGy does not affect its main volatile components.关键词：Ligusticum chuanxiong Hort;60Co-γ irradiation;Volatile constituent;Headspace solid phase microextraction-gas chromatography-mass spectrometry;Multivariate analysis
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发布时间：2024-08-26 - “聚乳酸塑料经60Co-γ射线辐照预处理，显著提升厌氧发酵效率，为资源化处置提供新思路。”摘要：Polylactic acid (PLA) plastic waste has significant potential for methane production in anaerobic digestion, but its slow degradation rate hinders efficient fermentation. Pre-treatment of PLA plastic waste can enhance anaerobic fermentation efficiency, promoting resource utilization. PLA plastic cup sample was pre-treated by irradiation with 60Co-γ ray to study the changes of PLA molecular structure and soluble substance content under the irradiation with absorbed doses of 0, 20, 40 and 60 kGy. And the effect of ionizing irradiation on the anaerobic fermentation performance of PLA samples was investigated by the proteolytic enzyme enzymatic digestion experiments and the changes of anaerobic fermentation gas production. The results showed that the lactic acid content in the supernatant of PLA samples irradiated by 60Co-γ ray increased slightly with the increase of absorbed dose in the range of 0~60 kGy. The molecular structure of the samples did not change significantly, but their crystallinity and molecular weight decreased significantly. The lactate concentration and mass loss of the irradiated samples increased significantly during the enzymatic digestion process compared to the unirradiated samples. Specifically, The PLA sample with an absorbed dose of 60 kGy reached its maximum lactate concentration on the 4th day, which was 17.4% higher than that of non irradiated samples. The mass loss increased over time, which was 68.7% higher than that of non irradiated samples on the 7th day. The irradiated samples took significantly less time to reach gas production equilibrium in anaerobic fermentation, and the total gas production increased by 3.0%. The results indicate that γ-ray irradiation has potential application as a pretreatment technology for PLA plastics, and this study can provide a theoretical reference for the resourceful disposal of PLA plastics.关键词：60Co-γ ray irradiation;Polylactic acid;Enzymolysis;Anaerobic fermentation
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发布时间：2024-08-26
RADIATION TECHNOLOGY APPLICATION
- “在核医学领域，研究者测量了225Ac及其子体平衡体系的剂量当量率，并与131I和99mTc进行了比较。结果显示，225Ac源在未屏蔽情况下的剂量当量率远超安全限值，强调了外照射防护的重要性，并提出了铅屏蔽的推荐厚度。”摘要：The dose equivalent rate of 225Ac and its daughter equilibrium system were measured and calculated. In addition, the dose equivalent rates of 131I and 99mTc with the same activity were also calculated. The tenth- and half-value thicknesses of lead for 225Ac were derived based on measurement data. The results show that dose equivalent rate at 0.5 m, for unshielded 85.5 MBq 225Ac, is 4.56 times higher than dose equivalent rate maximum limit 2.5 μSv/h of personnel operation positions form standard. The measured and theoretical values of dose equivalent rate at 0.5 m are more consistent than those at 0.15 m for 225Ac source, especially under lead shielding conditions of 0 mm, 5 mm, 10 mm, 15 mm, and 20 mm. For the same activity, measured dose equivalent rate of 225Ac is about half of 131I and about 1.5 times of 99mTc theoretical value. We should pay attention to external radiation protection during the use of 225Ac. It is suggested that, 20 mm can be used as the lead tenth value thickness, and 5 mm as the lead half value thickness conservatively for 225Ac and its descendants.关键词：225Ac;Lead;Radiation protection;Lead tenth value thickness;Nuclear medicine
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发布时间：2024-08-26 - “最新研究进展显示，专家利用COMSOL软件建模并推导了地铁隧道内不同通信频段的信号强度，验证了大尺度空间电磁环境计算方法的可靠性，有效提高了计算效率，并证明地铁隧道内电磁环境安全。”摘要：This study aimed to address the limitations of traditional electromagnetic numerical calculation methods in large-scale radio frequency (RF) space fields, accurately predict the electric field intensity of wireless communication signals in subway tunnels, and evaluate the safety of large-scale civil wireless communication electromagnetic environments in tunnels. To this end, COMSOL software was used to model the signal strength emitted by radiation terminals (leaky coaxial cables), which operate civil wireless communication systems of different types (3G, 4G, 5G) in small-scale space tunnels. Then, the simulation results for the small-scale space were theoretically calculated based on the radiation principle of a leaky coaxial cable. These results were used to derive the signal strengths corresponding to different civil communication frequency bands in the large-scale space of the tunnel. The prediction results of the signal received power in the tunnel were compared with the field measurement results: the root mean square error of the two was less than 1.58 dBm, thereby verifying the effectiveness of the signal strength model for different civil communication frequencies in a large-scale space tunnel. Subsequently, based on the calculated results of the signal strength, the extrapolation method was used to further calculate the maximum electric field intensities of 3G, 4G, and 5G in the civil communication environment within the large-scale space of the subway tunnel―0.143 V/m, 0.098 V/m, and 0.204 V/m, respectively. The calculated results of the electric field intensity were compared with the field measurement results in the tunnel: the root mean square error between the calculated and measured values was found to be less than 0.013 V/m. This result verifies the reliability of the proposed method for calculating the electromagnetic environment of civil communication in a large-scale space based on the signal strength modeling of a small-scale space. It further indicates that the proposed method effectively improves the calculation efficiency of the electromagnetic environment in the large-scale space inside a tunnel. The prediction results show that the maximum predicted power density of the electromagnetic environment in subway tunnels is only 0.005% of the public exposure limit of the International Commission on Non Ionizing Radiation Protection (ICNIRP), and the maximum predicted electric field strength is only 1.7% of the national electromagnetic environment control limit (GB 8702-2014), proving that the electromagnetic environment for civil wireless communication in subway tunnels is safe.关键词：Subway tunnel;Leaky coaxial cable;Large-scale space;Field strength prediction
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发布时间：2024-08-26
RADIATION PROTECTION
- “最新研究揭示了核电厂冷却塔排放对放射性扩散的影响，为核安全监管提供了重要参考。”摘要：During the normal operation of cooling towers in nuclear power plants, water vapor with a certain temperature is discharged through the outlet of the cooling tower, which mixes with the surrounding air. A portion of this vapor condenses and forms visible plumes. This paper uses Computational fluid dynamics (CFD) numerical simulation software to simulate six nuclear power units and their supporting cooling towers at a nuclear power plant site, and studies the impact of plumes emitted from the six cooling towers under different wind directions on the radioactive diffusion of the nuclear power plant discharge. The research results indicate that when the arrangement direction of the cooling towers is consistent with the wind direction，the influence of the cooling towers on the environmental flow field extends to a distance of approximately 1 500 m in the downwind direction. When the cooling towers are located in the downwind direction of the reactor unit, the emission from the cooling towers increases the pollution diffusion factor within a 1 000 m range of the chimney. As the environmental wind speed increases, the impact of the cooling tower emissions on the diffusion of pollutants from the chimney decreases.关键词：Cooling tower;Plume;Nuclear plant;Computational fluid dynamics
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发布时间：2024-08-26 - “在放射生物学效应研究领域，专家提出了金刚石微剂量探测器与生物组织能量分布等效换算新方法，为提高换算准确性提供新思路。”摘要：Diamond is considered a promising detector in radiobiological studies. However, the difference in densities between diamond and tissue imply that their energy deposition spectra are not identical, even for diamond and tissues of the same size. The energy deposition spectrum in diamond was converted to match a tissue sample of the same size. A method based on a mathematical model of energy deposition distribution and the Fourier transform was proposed. The results indicate that the spectra converted from diamond to tissue align closely with those of the tissue. Nevertheless, the applicability of this method is constrained by the mathematical model of energy deposition distribution. Thus, developing a mathematical model that describes the energy deposition spectrum under various conditions can enhance the applicability of this conversion method.关键词：Fourier transform;Diamond;Microdosimeter;Tissue equivalent conversion
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发布时间：2024-08-26
RADIATION INTERDISCIPLINARY RESEARCH
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