The fundamental mechanism of SERS (Surface ehanced Raman spectroscope), such as electromagnetic and chemical effect, as well as the synthesis of SERS tags with high enhancement, which will be applied in single molecule detection and single cell imaging, were discussed. For applications, SERS nanoparticle tags have been developed based on the use of embedded reporter molecules and a silica or polymer encapsulation layer. The SERS nanoparticle tags are capable of providing detailed spectroscopic information. These properties have raised new opportunities for multiplexed molecular diagnosis and in vivo Raman spectroscopy and imaging.

A series of PNIPA/PEG (poly (N-isopropyl acrylamide)/poly (ethylene glycol)) porous intelligent hydrogels, which exhibited appropriate phase transition temperature and fast response behavior, were synthesized by radiation polymerization with NIPA (N-isopropyl acrylamide) as monomer, PEG (poly (ethylene glycol)) as pore-forming agent and MBA (N, N-methylene-bis-acrylamide) as crosslinking agent. The surface morphology of the material was examined by the scanning electron microscopy. The influences of NIPA content and PEG molecular weight on swelling properties were discussed. Drug release properties were studied with aspirin as a model drug. The results showed that macropores were observed in the sample, whereas hydrogels prepared without using PEG had a dense surface. The swelling ratio and water loss ratio of the sample decreased with increment of NIPA content. LCST (Lower critical solution temperature) and the release ratio increased with PEG molecular weight. The release ratio of PNIPA/PEG6000 hydrogel at 37℃ was larger than that at 25℃ and the release mechanism could be described with Fickian diffusion type.

This review focused on the developments of three common microscopes in cell biology including far-field light nanoscopy, soft X-ray microscopy based on the synchrotron radiation light source, and three-dimensional cryo-electron microscopy. Their mechanisms, applications in cell imaging and the existing problems are discussed. The correlative microscopy combining several imaging methods can supply more information and may provide a new insight into cell biology in the future.

4-(2-hydroxy-3-ethoxy propoxy radicals) benzophenone (OEBP), a novel photoinitiator for free radical polymerization, was synthesized and characterized. The photopolymerization kinetics of 1,6-hexanediol diacrylate (HDDA) was studied with real-time infrared spectroscopy (FT-IR). When this photointiator was used to efficiently initiate polymerization of acrylates and methacrylates, there was an optimum cure rate with the increase in OEBP concentration. Both the polymerization rate and final conversion rate increased with the light intensity. The kinetics study of photopolymerization of HDDA showed that OEBP was more effective as a photoinitiator compared with benzophenone and benzophenone/ethyl-4-dimethylaminobenzoate (EDAB).

Photo-polymerization kinetics of acrylate monomer initiated by bis [2-(ochlorophenyl)-4,5-diphenylimidazole] compound photo-initiator system were investigated by real-time infrared (RT-IR), while NMR and UV was used for characterization, respectively. In synthetic system BCIM was used as pho-to-initiator, N, N-bis(diethylamino) benzophenone (EMK) was used as photo-sensitizer and N-phenylglycine (NPG) was used as hydrogen donor. The kinetics was determined by real-time infrared (RT-IR). The results showed that the polymerization rate and the double bond conversion increased with the initiator concentration while the mass ratio m(BCIM): m(EMK): m(NPG) was 10: 5: 5. The optimum initiate efficiency of 96.7% and the polymerization rate of above 90% with diacrylate monomer were better than that with triacrylate monomer. It was also found that the polymerization rate could increase with light intensity.

This paper is to evaluate and inspect the protective ability of the shielding walls and door with various thickness against the primary and secondary radiation coming from X-rays transferred by use of a medical accelerator according to the optimized parameters. The result indicates that the calculated thickness of the wall (except labyrinth interior wall) and accelerator facility roof could fit both the protection criterion and desired value of dose management for 15 MeV X-rays. Furthermore, the protective door should be added with a Pb layer of 8.3 mm and a polyethylene containing boron layer of 6.9 cm to meet the shielding requirement of X-rays and neutron, respectively.

Differing from high dose/high dose rate ionizing radiation which only induce an acute tissue damage effect when interacting with organisms, low dose/low dose rate ionizing radiation will induce chronic stochastic effects, hormetic effects and adaptive response under certain conditions. In this paper, the definition of low dose/low dose rate radiation and some theoretical and practical problems currently existing in the biological effect research of the low dose/low dose rate radiation, a systematic review of the biological effects induced by low dose/dose rate radiation and some characteristics of the effects are introduced.

Oxidative stress can initiate genetic and epigenetic alterations. Oxidative stress-induced genetic changes mainly involve that ROS attacks DNA, inducing various DNA changes like strand breaks, base modi?cations, DNA-DNA and DNA-protein cross linkages which are all strongly implicated in the initiation stage of tumorigenesis. In oxidative stress-induced epigenetic changes, one of the most important mechanisms is the change of DNA methylation levels: hypermethylation-induced transcriptional repression (in the case of tumor suppressor genes) or hypomethylation-induced activation (in the case of oncogenes), which is closely associated with tumorigenesis. In this paper, the current status of knowledge on the role of ROS-induced oxidative stress in altering the genetic and DNA methylation during tumorigenesis was introduced, and the developing tendency of tumor therapy was prospected.

To investigate the effects of AS1411 on cell proliferation-toxic and radiosensitivity on cervical cancer HeLa cells, CCK-8 assay was used to determine cell proliferation-toxic effects on HeLa cells, and the effect of AS1411 on the radiosensitivity of the cells was observed by clonogenic assay. The results showed that the cell toxicity of AS1411 was very small, and all the survival rates of HeLa cells were more than 95% under the condition of  different concentration of AS1411 (0 nmol/L, 50 nmol/L, 100 nmol/L, 250 nmol/L and 500 nmol/L) and the cells for 24 h, 48 h and 72 h, respectively. Clonogenic assay result shows that AS1411 combined with X ray irradiation can decrease the clonogenic survival rate of HeLa cells, and the sensitive enhancement ratio (SER) of HeLa cells are 1.06, 1.58 and 1.89, respectively with different drug concentrations of 100 nmol/L, 250 nmol/L and 500 nmol/L. This study proves AS1411 might enhance the radiosensitivity of the HeLa cells.

Cancer stem cells (CSCs) are defined as a portion of cancer cells thatare characterized by self-renewal, asymmetric division and multipotential differentiation. CSCs are believed to be the main causes of tumor metastasis, neoplasm recurrence and chemoradiotherapy resistance. CSC supports a new view in ourunderstanding of the cancer, which suggests that only when the "seeds" of cancer are cleared, can cancer radioresistance be effectively overcome. Here we take a look at the primary articles in the literature studying the mechanism of cancer radioresistanceand CSC and summarize them for review.

Three fields were captured with 6 MV photon beam, using a-Si EPID(SDD 100cm).Then the derived dose images were split into four regions and every region could be modified by using different methods to build models. The three dose comparison methods most commonly used in radiotherapy were used to analyze the absorbed doses in four regions. The result shows that the percentage dose difference comparison method is sensitive in steep dose gradient regions where small spatial offsets between two distributions may present large dose difference, while it works well in regions of relatively shallow dose gradients. In contrary, the DTA (distance-to-agreement) method is sensitive in shallow dose gradient regions where a large DTA value may be calculated for small dose differences, while it performs well in steep dose gradient regions. However, as the gamma method has referenced the merits of percentage dose difference and DTA, it performs well both in steep and shallow dose gradients and produces the lowest error. So the gamma comparison method can be performed better in clinical dosimetric verification.

Pentadecafluoro-octanoic acid 1-(4-benzoyl-phenoxymethyl)-2-hydroxy-ethyl ester(EBPFOA) was synthesized with (4-Oxiranylmethoxy-phenyl)-phenyl-methanone (EBP) and Pentadecafluorooctanoic acid (PFOA), which was characterized by FT-IR, 19F NMR, and UV absorption spectra. Real time infrared spectroscope (RT-IR) was applied to investigate the effects of different monomer system, various light intensity and concentration of photo-initiator on the polymerization kinetics and the ability of EBPFOA to overcome oxygen inhibition. The results indicate that the rate of polymerization (Rp) and final double bond conversion increase with increasing light intensity. In a certain range, the higher the concentration of initiator, the higher the double bond conversion and the faster the Rp. EBPFOA shows good ability to overcome the oxygen inhibition.

Relative biological effectiveness (RBE), a major factor to determine the absorbed dose, is an important parameter of radiotherapy. Differing from that in the conventional radiation, RBE is a variable value and related with many biological and physical factors in heavy ion therapy. The paper reviews the elements that influence RBE, and briefly introduces the methods to calculate RBE in Japan, German and China.

The Geant4 code was used to model components of the head of Siemens medical linear accelerator with the field commonly used. Then we simulated the process of electron beams, which could produce 6 MV X-rays, bombarding a gold target. By comparison with the measured data, we ensured that the model was built correctly. Then we obtained the information of all the particles to the field plane, and wrote it to a phase space file. The kinds of particles and their average energy, energy spectrum distributions, particle fluence distributions, energy fluence distributions, and angular distributions were presented by processing the file with the procedure written by myself. The results show that the average energy of photon is higher than that of electron and positron; energy spectra of photon and electron show continuous distributions; electronic particle fluence is two orders of magnitude less than that of photons; particle fluence and energy fluence of photons are evenly distributed in the field and decrease rapidly out of the field, while the electronic’s fluctuate considerably in the field and smoothly out of the field. Angular distribution of photon is mainly concentrated within the range of 10° off the central axis, while the electronic’s are in a relatively larger range.

A series of organosilicon modified epoxy monoacrylates (OMEMA) containing both C=C (UV-curable groups) and epoxy (heat-curable groups) were synthesized, and a number of UV-heat curable systems were prepared. The influence of the length of the organosilicon segment on the gel content, water absorption, mechanical, volume shrinkage and thermal characterizations of UV-heat cured films using modified epoxy monoacrylates as resins were measured. Compared to the epoxy monoacrylates (EMA), UV-heat curable systems with the same active diluents, the gel contents of UV-heat cured films of OMEMA systems were about 97% and was similar to the EMA systems. Its breaking strength decreased. However, the relative elongation UV-heat cured films of OMEMA systems increased from 4.8% to 14.1%, and volume shrinkage was decreased from 6.19% to 4.93%. The decomposition temperature of UV-heat cured films was increased.

Gel properties of muscle protein are the important functional characteristics in meat and its products, which determine the meat products’ unique quality, such as texture, juiciness, fat content and sensory characteristics. As a novel food preservation technology, irradiation may lead to changes in the composition and structure of protein molecule, and impact the gel forming ability and gelation properties of muscle protein. Based on the introduction of gel forming mechanism of muscle protein, effects of irradiation on the water holding capacity, mechanical properties and structure of muscle protein gel were reviewed in detail. High-dose irradiation could weaken the water holding capacity of muscle protein and result in the loss of meat juice. With different irradiation conditions or raw materials, influences of irradiation on the texture and rheological properties of muscle protein gels are different, and effects on the structure of muscle protein and its gel are more complex. Finally, the research trend of irradiation effects on the gelation properties of muscle protein is put forward in this paper.

Electromechanical products exported to the EC market for wire and cable applications must meet the requirements of the RoHS. Blends consisting of high density polyethylene (HDPE)/ethylene vinyl acetate copolymer (EVA) and magnesium hydroxide (Mg(OH)2) as a matrix were investigated by electron beam irradiation. The method of cross-linking and adding an auxiliary flame retardant solution overcomes the problem that arises from a high loading of halogen free flame retardant that results in poor material performance. The effects of various components on material performance were analyzed. The established relationship can be used in actual production to provide heat resistance, be flame retardant, low smoke, halogen free and have irradiation cross-linking to optimize cable material formulation. The main performance index meets the national standard of 125℃ heat radiation cross-linking of a low smoke zero halogen flame retardant polyolefin insulation material, as well as related EU requirements.

Low-dose ionizing radiation becomes a focus on the domain of radiation biological effects. Theories about the harmful effects, adaptive effects and the excitatory effects of low-dose ionizing radiation are progressed. The harmful effects of low-dose ionizing radiation coexist with the non-deleterious effects, and the mechanism in which harmful effects and non-deleterious effects exist as a whole remains unclear at present. In the past, the low-dose ionizing radiation biological effects were linearly extrapolated from the high-dose effects curves. However, scientists increasingly question the validity of the linear no-threshold model in predicting the biological effects of low-dose ionizing radiation. The occurrence and mechanism of the three radiation biological effects of low-doses ionizing radiation are summarized and some may be helpful for further research project.

UV-curable phosphorus-containing epoxy resin was synthesized with chain-extension of (3,4-epoxycyclohexyl)methyl-3,4-epoxycyclohexanecarboxylate (ERL4221) and 2-(6-oxido-6H-dibenz(c,e) (1,2)- oxaphosphorin-6-yl)-1,4-benzenediol (DOPO-HQ) at different stoichiometric ratios. The structures of these resins were characterized by IR and 1H-NMR. The influences of different phosphorus contents on the epoxy value of the epoxy resin, thermal properties, flame retardancy, and UV curing properties were investigated. The results showed that the thermal stability and flame resistance increased compared with those of the unmodified ERL4221 epoxy resin under the same conditions. When the phosphorus mass content was 1.5%, the limiting oxygen index (LOI) reached 24.9, vertical burning achieved V-1 levels, and had a higher light curing activity.

Circular dichroism (CD) spectroscopy is one of the powerful tools for DNA structure research. Currently, the general CD spectrometer can only obtain the CD signal with wavelength above 190 nm, and the noise is very high with the wavelength range of 190−220 nm because of the influences from the air, the solvents, and the salt ion concentration of the buffer, etc., making it have not much practical value. The development of the synchrotron radiation circular dichroism (SRCD) makes it possible to obtain the CD signal of the DNA structure in the region of the vacuum ultraviolet (VUV). And now it becomes a new powerful tool for studying the DNA structure. This work firstly introduces the principle and features of SRCD technique, especially its advantages in the DNA structure research. Then the DNA structures and the factors affecting the CD signal are also reviewed. Finally, some typical DNA structures are taken as samples to analyze their SRCD spectrum.

Phenyl cycloaliphatic epoxy-silicone oligomers (Ep-Ph-SiO) with different contents of benzene rings and epoxy groups were synthesized via sequential hydrosilylation reactions of methylhydrogen silicone oil by attaching styrene first, which was followed by reacting with 4-vinyl-1-cyclohexene-1,2-epoxide in the presence of Lamoreaux catalyst. The contents of benzene rings and epoxy groups in the monomers were determined by 1H-NMR. The refractive indices (RIs) of the obtained oligomers were measured and the cationic photo-polymerization of these oligomers was studied by using triarylsulfonium hexafluorophosphate (P-S) as photo-initiators exposed to a high-pressure mercury lamp. The results showed that the phenyl cycloaliphatic epoxy-silicone oligomers exhibited higher photo-polymerization activity than diglycidyl ether of bisphenol-A epoxy resins and the benzene rings could improve the RIs of cycloaliphatic epoxy-silicones.

The PUA was prepared with 2,4-tolylene diisocyanate, polyethylene glycol, and hydroxyethyl acrylate. The electron beam was used to cure the coatings. The samples were characterized by FTIR and TGA to investigate the law of the absorbed dose and the properties of the products after electron beam curing. The results showed that the absorbed dose had great effects on the characterization of the cured PUA coatings, and the samples irradiated with dose of 60−80 kGy had good mechanical properties, high gel fraction and thermal stability.

Core-shell magnetite/polyethyleneimine nanoparticles (Fe3O4/PEI) were synthesized by a precipitation method using polyethyleneimine (PEI) as a stabilizer. Au colloids-modified magnetic nanocomposites (Fe3O4/PEI/Au) were then prepared by a photochemical method in a HAuCl4 aqueous solution, using Fe3O4/PEI as the magnetic core. The samples were characterized by transmission electron microscope, X-ray diffraction and vibrating sample magnetometer. The results showed that Fe3O4/PEI nanoparticles with a mean size of 6.8 nm were quasi-superparamagnetic and the saturated magnetization is at about 37.4 A?m2?kg-1. The obtained Fe3O4/PEI/Au is irregular in shape, composed of a sub-micron aggregate of Fe3O4/PEI nanoparticles and some Au colloids with sizes ranging from 13 nm to 23 nm. Additionally, the quasi-superparamagnetic nanocomposites are magnetically susceptible and the saturated magnetization reaches 36.9 A?m2?kg-1. Therefore, Fe3O4/PEI/Au nanoparticles can be used in many areas including bioseparation and biosensors.

The current understanding of the cells, cytokines, and the key factors linked to the signaling networks implicated in RILF were summarized. Targets with potential therapeutic effects for the treatment of RILF were also be discussed and listed. From all above, we hope to provide researchers with ideas in studying the drugs with prevention and (or) the treatment of RILF.

The beam dose distribution is compared with those obtained from Monte Carlo (MC) simulation and measurement to investigate dosimetry characteristics for X-ray fields. The beam data, including percentage depth dose (PDD) and off axis ratio (OAR), were acquired by measurement and MC calculation in water phantom for Varian 6 MV X-ray fields. The results were compared and analyzed. The match result, for PDD of the field of 10 cm × 10 cm, has shown 96.47% agreement for r ≤1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution at the depth of 0 to 20 cm, and 99.23% for r≤1 with 3% delta dose and 3 mm DTA. The match result of OAR has shown 97.56% agreement for r ≤1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution, and 99.42% for 
r ≤1 with 3% delta dose and 3mm DTA. Electron dose is 5.3% of depth dose for 10 cm × 10 cm, and 15.2% for 40 cm × 40 cm. Dose distribution can determined through the measurement and calculation in fields.

A detailed GEANT4 Monte Carlo study was performed to calculate the dose rate distributions of an industrial 60Co γ-rays irradiation facility, so it could provide a better service for the research of radiation hardening. All data produced during simulations were on-line stored and off-line analyzed by ROOT. With careful design of simulation processes, the relative errors were less than 5%. For the validation purpose, experiments with ferrous sulfate dosimeter were carried out. Furthermore, a computational model was constructed as a comparison. The relative deviations between simulated and experimental results were less than 5%. The satisfactory agreement of simulations between model and measurements indicates that our work has designed the processes of simulation and got the dose rate distributions in a correct way.

The branches of tradescantia fiumiensis were irradiated with carbon ions, and the initial energy of the carbon ions was 95.8 MeV/u (dose rate 4 Gy/min, dose range 0−20 Gy). A mutant line with pink leaves was obtained. The aim is to explore the mutation mechanism of the mutant with pink leaves obtained by carbon ions irradiation in tradescantia fiumiensis. pH differential method was used to evaluate the total anthocyanidin content of wild type and its mutant with pink leaves. HPLC-MS method was used to detect the anthocyanin pigmentation between wild type and its mutant with pink leaves. The total anthocyanidin content of the mutant was 18 fold than that of wild type. Seven anthocyanins were determined and identified as pelargonidin, cyaniding, petunidin, malvidin, pelargonidin-3-glucoside, peonidin-3-glucoside and cyanidin-3-O-rhamnosylglucoside in the mutant; Six anthocyanins were determined and petunidin could not be detected in wild type. The results showed that, compared with wild type, the total anthocyanidin content increased and the components of anthocyanin were also changed in the mutant.

In this work, micron-scaled sulfonated crosslinked polystyrene (SCPS) microspheres were prepared, and dispersed in water/styrene binary mixture as seed microspheres. The system was irradiated by 60Co g-rays after single-body swelled, and SCPS microspheres with grooved surface were fabricated. Two parameters, the content of crosslinking agent (DVB) and the sulfonation degree of the original SCPS seed microspheres, which influenced the final microspheres facial morphology were studied. The results show that walnut-like microspheres would be formed when the above two parameters are low, and plum-like microspheres prevail with increase of these two parameters. However, the special facial morphology has nothing to do with a certain dose rate range at 44−108 Gy•min−1. This work provides a facile and effective way to prepare polymer microspheres with roughness surface.

Poly (acrylic acid)-functionalized magnetic nanoparticles (Fe3O4/PAA) were synthesized by polymerization of acrylic acid initiated by UV light. CdS-modified Fe3O4/PAA composite particles (Fe3O4/PAA/CdS) were photochemically prepared in aqueous solution containing cadmium sulfate and sodium thiosulfate with Fe3O4/PAA as the magnetic core. The composite particles were characterized by infrared spectroscopy (IR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), photoluminescence measurement (PL), and vibrating sample magnetometer (VSM). The results show that the mean size of Fe3O4/PAA/CdS spheres with core-shell structure and rough surface is about 155 nm and the size distribution is rather wide. The composite spheres also exhibit luminescent and quasi-superparamagnetic properties. Besides, the magnetic composite spheres possess excellent activity as a recyclable photocatalyst for the degradation of Rhodamin B when exposed to visible light irradiation and can be covered by a magnet from aqueous solution within 2 min.

Using trimethylopropane trimethylacrylate (TMPTMA) as crosslinking sensitizer, ethylene propylene dine terpolymer rubber (EPDM) was vulcanized by 60Co irradiation method. It has been found that the gel fraction of EPDM increases with the TMPTMA dosage and the appropriate dosage is 8% in weight percentage to EPDM. Tensile strength increases with the absorbed dose until 120 kGy. And the adopted absorbed dose is about 80 kGy. At the same time, the properties of aging resistance and thermal stability of radiation vulcanizate are improved compared with chemical vulcanizate. TG results show that the thermal decomposition temperature of radiation vulcanizate (480℃-530℃) is higher than that of chemical vulcanizate (430℃-480℃). These experimental results indicate that the properties of aging resistance and thermal stability of radiation vulcanizate are better than those of chemical vulcanizate.

 We aim to investigate the effect and mechanism of resveratrol on radiosensitivity of lung cancer A549 cells. MTT was used to detect the cell toxicity of different concentrations of resveratrol on lung cancer A549 cells; clonogenic assay was performed to determine the function of growth inhibition. The DNA damage was detected by the comet assay. Western blot was taken to detect the expression level of Survivin. The results showed that the inhibitory effect of resveratrol on A549 cells increased with resveratrol concentration and time; the combined effect of resveratrol and radiation significantly increased the DNA damage of A549 cells induced by radiation(p<0.05), and reduced cloning efficiency as well as the expression level of Survivin. It can be concluded that resveratrol can enhance the radiation sensitivity of A549 cells, and maybe the radiosensitizing effect is achieved by suppressing the expression of Survivin protein.

After X-rays or γ-ray irradiation, fingernails as biomaterial having good radiosensitivity, would generate free radicals. Electron paramagnetic resonance (EPR), a tool which can qualitatively and quantitatively measure free radicals, has been used to detect the radical concentration induced by irradiation so that estimate irradiated dose of victims and conduct triage. As an immature dosimetry method, it still has many problems, and some researchers are unfamiliar with quantitative utilization of electron paramagnetic resonance. Therefore, the theory, matters needing attention and recent progress of fingernail electron paramagnetic resonance quantitative measurements will be reviewed.

Nanoscale zero-valent iron coated with carboxymethyl cellulose was used to remove 210Pb(II) from aqueous solution. The effects on removal result of coated NZVI/CMC concentration, solution pH value, initial 210Pb(II) radioactivity, and contact time were investigated. The characterization of coated NZVI/CMC before and after reaction was analyzed by SEM and XRD. The results show that the removal rate or absorption capacity reaches 99.25% with the pH value of 5.5, the initial 210Pb radioactivity of 2.354×103 Bq?L−1, the coated NZVI/CMC concentration of 0.8 g?L−1, and the contact time of 60 min. Great changes occur to coated NZVI/CMC has after reaction, and the hammer throw reticular structure turns to lamellar structure. Coated NZVI/CMC still has rather good removal effects on 210Pb(II) in aqueous solution.

With the rapid development of radiation sterilization, the radiation resistant polymer for medical use has become a hot research topic in both basic and practical point view. In this paper, the recent progress of medical radiation resistant polypropylene (PP) was reviewed. Not only the radiation degradation mechanism of polypropylene, but also the color change mechanism and the preparation of radiation resistant were involved. The paper focused on the preparation of radiation resistant polypropylene and the challenge in preparation of the medical material and its future development were discussed.

With the development of biological technology, the study on biological effects induced by heavy ion beam irradiation is undergoing the transition from phenotype to genotype,  qualitation to quantitation both on the research methods and research objects, and gradually into the molecular level. At the molecular level, the living matter have specific behaviors of damage and repair when irradiated by heavy ion beam, this biological effects could be quantified by the related mathematical models, meanwhile, the studies of bystander effects induced by heavy ion beam irradiation are important to decrease the damage of healthy tissue in heavy ion radiotherapy.

Polypropylene (PP) was irradiated by γ-rays, and then foamed with supercritical carbon dioxide. The effect of absorbed dose on melting temperature, shearing viscosity, and melt mass-flow rate (MFR) of radiation modified PP was characterized by means of differential scanning calorimeter (DSC), advanced rheology expand system (ARES), melt flow rate testing instrument, and the morphology of PP foam was investigated by scanning electron microscopy (SEM). The results showed that the melting temperature and viscosity of PP decreased after γ-ray irradiation. The foamability of radiation modified PP is improved and a higher foam volume expansion ratio is obtained after radiation modification. At a given foaming pressure, foaming of radiation modified PP needs a lower temperature than that of original PP.

Flow cytometry analysis method was used to detect the changes of γH2AX protein expression in human peripheral blood lymphocytes. In the dose-effect study, peripheral blood was irradiated by 60Co γ-rays with the dose of 0-6 Gy and cultivated for 1 h. Peripheral blood were cultivated for 0-24 h after 4 Gy 60Co γ-rays irradiation for the time-effect study. Then, the peripheral blood was divided into four treatment groups, i.e. UV irradiation, 60Co γ-rays irradiation, UV plus 60Co γ-rays irradiation and control group to detect the changes of protein expression in different time. The results showed that the γH2AX protein expression was in a dose-dependent form. The expression of γH2AX peaked at 1 h after 4 Gy irradiation and began to decrease quickly. The expression of γH2AX in UV irradiation group increased compared with that of the sham-irradiation control group, and the expression of γH2AX peaked at 6 h. While compared with that of the 60Co γ-rays group, the γH2AX expression of UV combined 60Co γ-rays group was unchanged. The results reveal that the detection of γH2AX protein expression changes in peripheral blood lymphocyte by flow cytometry analysis is reasonable and may turns be a new way for biological dosimeter.

With the development of nuclear technology industry, irradiation sterilization has become an interna-tionally used sterilization method for health care products. But it is difficult to choose the appropriate methods and procedures of radiation sterilization dose setting for health care products by using international standard ISO11137-2: 2013. The sterilization dose setting methods and procedures in ISO11137-2: 2013 are divided into 12 sub categories according to 5 key factors of difference and based on which the screening table of sterilization dose setting methods is developed. The screening table can help users to make a quick and appropriate choice when dealing with sterilization dose setting method choosing problem for a brand new health care product and find the corresponding experimental procedures.

To study the influence of ultra high voltage (UHV) AC transmission line frequency electric field on the human body, finite element analysis method was used to calculate electric field effect of the simplified human body model under 1000 kV transmission line. Then, comparative analysis of different towers was carried out to show the differences in the induced electric field and its distribution in the human body. The results indicated that electric field around the body is not evenly distributed, and distortion was produced; current density in the small parts of human body (e.g. the neck and legs) is high; compared with compact transmission lines, normal transmission lines induce smaller current density in the human body; the maximum induced current in the central nervous system is much smaller than safety limits of 2 mA?m−2; electric filed strength in the central nervous system under normal transmission lines is high, but the maximum induced electric field is still less than 20 mV?m−1, which is the phosphene threshold value. Studies demonstrate that induced current and electric field in the human body under UHV AC transmission line are both less than the reference levels from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The results can not only provide the basis for calculation of electromagnetic exposure of the real human body, but also provide reference for electromagnetic exposure assessment standard of UHV power transmission engineering in China.

Ionizing radiation can cause damage on DNA (such as physically breaking one or both of the sugar phosphate backbones, breaking the base pairs or hydrogen bonds of the DNA), inhibit synthesis of DNA and promote degradation of DNA. These effects will further change the configuration of DNA self-assembled nanostructures, which can be applied in detection of ionizing radiation. This work reviews the developments of DNA self-assembly technology in recent years, and introduces the applications of DNA self-assembly in ionizing radiation detection, especially in detection of α and β particle radiations based on DNA tile self-assembly.

The requirement of disposable medical protective clothing and other medial items has been increasing sharply since the novel coronavirus pneumonia (NCP/Coronavirus disease 2019, COVID-19) outbreak in January 2020 in Wuhan city, it is demanded to find a fast and reliable way to sterilize or disinfect medical protective clothing. Ethylene oxide (EO) gas has been widely adopted in China to sterilize disposable medical protective clothing, but the total period of this sterilization process normally requires 7~14 d because the release of contaminated EO from clothing takes a long time. However, ionizing radiation sterilization by gamma ray or electron beam can be completed in one day, being much faster than traditional EO sterilization. To promote radiation sterilization of medical protective clothing, China Isotope and Radiation Association (CIRA) organized national experts to draft a temporal standard of radiation sterilization of disposable medical garments by gamma ray or electron beam, in both Chinese and English versions. This standard has already been accepted by radiation sterilization service industry, a large number of medical garments have been disinfected by irradiation. Radiation sterilization is believed to be widely used in the future for disinfection of medical clothing and other items.

Modification of low-density polyethylene (LDPE) by grafting it with a maleic anhydride (MAH) was conducted using a co-irradiation technique at room temperature under a vacuum atmosphere at absorbed doses of 10 kGy, 25 kGy, 50 kGy, and 100 kGy. The effects of the absorbed dose on the chemical structure and physical properties of LDPE-g-MAH were investigated. The Fourier transform infrared spectroscopy showed that the MAH was grafted onto the LDPE surface successfully. The grafting degree of the MAH increased with the absorbed dose. The melting temperature (T_m) and thermal degradation temperature (T_5%) of the LDPE-g-MAH films decreased with the increasing absorbed doses because of the occurrence of crystal defects of LDPE caused by irradiation. However, the morphologies and crystal forms of LDPE did not change after irradiation. This work provides an effective strategy for radiation graft modification of LDPE.

In an ethanol/water system and N₂ atmosphere, graphene oxide and the silver ions were simultaneously reduced by a one-step gamma ray irradiation method and self-assembled into graphene/silver (GH/Ag) composite porous hydrogel materials with a three-dimensional structure. GA/Ag composite porous aerogels were obtained by the freeze-drying method. Scanning electron microscopy observed that GA/Ag composites have a honeycomb-like network structure. Transmission electron microscopy analysis revealed that silver nanoparticles have a size range of 20~60 nm. The results of X-ray photoelectron spectroscopy, X-ray diffraction and thermogravimetric analysis showed that the C element content in the GA/Ag composites increased, the O element content decreased, and Ag⁺ was reduced and thermal stability increased. Due to the synergistic catalysis between graphene and Ag nanoparticles, GA/Ag composites demonstrated excellent catalytic performance and catalyzed the concentration of 4-nitrophenol up to 2.16×10^-3 mol/L. When the concentration of 4-nitrophenol was 0.72×10^-3 mol/L, the first-order kinetic constant k was 1.53 min^-1, which was higher than those synthesized by chemical methods.

The fabrication of boron nitride nanosheets (BNNS) by the exfoliation of hexagonal boron nitride (h-BN) remains a challenging task in the field of two-dimensional material (TDM) preparation. Radiation-induced reduction-exfoliation (RIRE) is a new method of preparation of BNNS from h-BN. RIRE is achieved by the disruption of the interlayer interactions in a h-BN crystal by means of the volume expansion caused by the formation of Ni nanoparticles (NiNPs). NiNPs are formed via the radiation reduction of Ni^2? ions intercalated between the h-BN crystal layers. As a result, sheet-like NiNP (approximately 20 nm)-bound BNNS (Ni/BNNS) in 200 nm squares, with an average thickness of less than 5 nm, was successfully peeled from h-BN under ambient temperature and pressure conditions in an alcohol/water medium. The prepared Ni/BNNS exhibited excellent catalytic performance, good structural stability, and viability for magnetic separation, which make Ni/BNNS recyclable. More notably, when the water/methanol dispersion containing Ni/BNNS was exposed to simulated sunlight irradiation, H₂ evolution of 8 404.3 μmol/g Ni within 2 h was detected. Therefore, this work provides a new means for the preparation of BNNS by the efficient exfoliation of h-BN, introduces a one-step preparation method for novel TDM-supported nano-metal catalysts, and offeres new insight into the catalytic mechanism of visible-light catalysts.

Epoxy resin and its composites are widely utilized in the nuclear industry. In this work, epoxy composites were prepared by blending hexagonal boron nitride (h-BN) powder with tetrahydrophthalic acid diglycidyl ester, methyltetrahydrophthalic anhydride (curing agent), and 2,4,6-tris (dimethylaminomethyl) phenol (catalyst), followed by a thermal-curing process. The structure and properties (such as thermal stability, mechanical properties, and thermal conductivity) of the prepared h-BN/epoxy (h-BN/EP) composites were investigated before and after irradiation using ⁶⁰Co γ-ray under an air or nitrogen atmosphere at a certain absorbed dose rate (60 Gy/min). The results showed that h-BN powder had good structural stability under γ-ray radiation at absorbed doses up to 380 kGy. However, the glass transition and initial thermal decomposition temperatures of the h-BN/EP composites were significantly lower than those of the pure EP matrix after γ-ray radiation. The effect of γ-ray radiation on the mechanical properties of h-BN/EP composites depends on both the h-BN content and the absorbed dose. For the composite with a low h-BN content (mass fraction<0.52%), the tensile strength decreased remarkably even after the composite was irradiated by γ-ray at a low absorbed dose (≤180 kGy). In contrast, for the composite with a higher h-BN content (mass fraction≥0.52%), the tensile strength increased significantly after the γ-ray radiation at the same absorbed dose. When the absorbed dose was 1 000 kGy, the tensile strengths of the irradiated pure EP and all irradiated h-BN/EP composites were the same, i.e., they had no relationship with the h-BN content. These results indicate that the thermal conductivity of the h-BN/EP composites will be greatly improved after γ-ray radiation at the absorbed dose of 180 kGy.

Conventional textile dyeing industries use small molecular weight organic dyestuffs, where the unreacted dyestuff molecules generate large quantities of refractory wastewater and cause serious problems to the environment. This highlight reports on the latest article for textile dyeing through the radiation-induced graft polymerization (RIGP) method, where carbon-carbon double bond functionalized nanoparticles including carbon black, cobalt blue, cobalt green, and iron red were immobilized on the surface of cotton fabric. The wastewater generated in this process can be discharged directly, as the concentrations of the contaminants are lower than those of the international standard and Chinese national standard requirements. The fastness of the color is ensured by the covalent bonding between the nanoparticles and the cellulose macromolecules, which remains unchanged after 100 domestic laundering cycles.

Research on interface reactions in radiation environment is focused on the reaction of the radiolysis products of water and the physical/chemical changes of solid materials in the heterogeneous system. In this paper, we review the research on the reactivity of H₂O₂, the typical radiolysis product of water, which may trigger one or two reactions among oxidative dissolution (corrosion), catalytic decomposition, and Haber-Weiss or Fenton-like reaction in aqueous phase. The kinetics, thermodynamics, reaction mechanism, and governing factors of the above-mentioned reactions will be discussed later in detail.

Hydrogels are hydrophilic, three-dimensional, polymeric networks that exhibit good biocompatibility, large water absorption ratios, strong water retention abilities, and the ability to mimic extracellular matrix structures and functions. Therefore, they are suitable for use in wound healing, tissue engineering, and drug delivery applications. Radiation techniques are simple, safe, and clean processes that have been employed to prepare high-quality hydrogels, including for mass production. Additionally, these radiation techniques retain biopolymer biocompatibility and ensure that modification and sterilization steps are completed simultaneously; this affords new opportunities for bio-applications. This paper summarizes the current research status of hydrogels in China, including their preparation by radiation technology and their biomedicine applications, and discusses prospective directions for future hydrogel research.

Silicon carbide (SiC) neutron detector is suitable for monitoring in elevated temperature and harsh radiation environment owing to its wide band gap. An experimental test system of SiC neutron detector was established using standard radioactive sources, and the responses of SiC neutron detector irradiated by ²⁵²Cf and ⁶⁰Co standard sources were investigated, respectively. It was found that the SiC neutron detector could work at a low bias voltage, the R² value of the linear fitting between the counting rate and the incident neutron flux of the detector is 0.999 8 under the ²⁵²Cf source irradiation, which showed a very good linear relationship. In addition, the count of the SiC neutron detector under the ⁶⁰Co source irradiation was observed mainly in the low-energy area, which could effectively distinguish the effect of γ-ray by setting the discrimination threshold.

In this study, the values of electron beam energy and dose parameters of a 10 MeV electron accelerator were measured and analyzed in detail in order to optimize the parameters used for equipment detection and improve the existing irradiation processing technology. First, the values of most probable energy and the average energy of the accelerator were estimated using the national standard aluminum lamination method. Then, the optimal penetration depth and depth dose distribution curves of the electron beam in four typical uniform materials of varying densities — PP (Polypropylene) plastic board, decorative low density board, PVC (polyvinyl chloride) foam board, and PVC acrylic board were measured and analyzed. The results demonstrated that the average energy of the electron beam was 9.42 MeV, which is slightly less than the most probable energy of 10.01 MeV, and it was concluded that the average energy is more suitable for the formulation of processing technology. Further, the dose uniformity ratio (DUR) was observed to be inversely proportional to the density of the medium, and their ratio values are 1.2, 1.28, 1.34, and 1.46 for the above four materials. it is opposite to gamma radiation situation. The relations between penetration depth and material density, and dose uniformity ratio and material density, were obtained via the empirical fitting method, which exhibit positive consequence with respect to the formulation and improvement of standardized irradiation processing.

A novel gelatin/polyacrylic acid/poly(N-isopropyl acrylamide) shape-memory hydrogel (GAN) with temperature and pH response and high strength was prepared by two-step irradiation method, with gelatin as matrix, acrylic acid (AAc) and N-isopropyl acrylamide (NIPAm) as monomers, and N,N′-methlene bisacrylamide (MBA) as crosslinking agent. The structure, morphology, mechanical properties, and shape-memory behavior of GAN were investigated in detail. The results showed that GAN has a dense network structure, and excellent mechanical properties with the maximum tensile strength up to (5.4±0.3) MPa, and the maximum elongation at break of 745%. GAN’s shape recovery time at 60 ℃ and pH=12.8 can be controlled within 10 s and 15 min, with a shape fixation rate and shape recovery rate above 90%, respectively. This work provides a new method for the preparation of environmentally responsive high-strength shape-memory hydrogels.

4-Amino-1,2,4-triazole (ATZ) was introduced into ultra-high molecular weight polyethylene (UHMWPE) fibers by pre-radiation grafting to prepare UHMWPE-g-(GMA-ATZ) fibers. The effect of the initial pH Au(III) adsorption by UHMWPE-g-(GMA-ATZ) fibers and the adsorption mechanism of Au(III) on the functional fiber were investigated. The adsorption efficiency of Au(III) reached 98.7% when the solution pH was 2, Au(III) concentration was 50 mg/L, and adsorbent concentration was 2 g/L. Scanning electron microscopy, X-ray diffraction and X-ray absorption near-edge structure showed that Au mainly existed on the fiber as metallic Au particles. Fourier transform infrared spectroscopy revealed that the imino groups (-NH-) disappeared after Au(III) adsorption, generating carboxyl groups. The adsorption mechanism of Au(III) on the UHMWPE-g-(GMA-ATZ) fiber is based on the redox reaction between Au(III) and -NH- on the fiber, accompanied by the formation of carboxyl group and the reduction of Au(III) to zero valence Au. This functional fiber can be used to facilitate a simple and efficient method for precious metal recovery from wastewater.

The radiation protection effect and mechanism of epigallocatechin-3-gallate (EGCG) were reviewed by analyzing and summarizing the literature. EGCG has a radiation protection effect on the hematopoietic system, immune system, and radiation lung injury, and its mechanism of action is related to its scavenging of free radicals, anti-oxidation, anti-apoptosis and other effects.

Silicone rubber are widely used in engineering for their excellent properties. When exposed to high-energy rays or particles, such as existing in aerospace and nuclear power plant applications, silicones would age. The irradiation-induced crosslinking and radiolysis lead to decreasing of material properties and thus influencing the service lifetime. Many factors affect the aging behaviors and make it hardly to predict. This article reviews the recent research progresses in this field and summarizes the effects of absorbed dose, dose rate, environment factors, and additives on radiation aging of materials. In addition, the characterization, simulation and modeling of irradiation-induced aging are also discussed. The thorough survey of the current literatures offers useful guidance to predict lifetime of the silicones.

Tumor-associated fibroblast gene expression microarray data were obtained from the GEO database (GSE37318). Data were screened for differentially expressed genes using GEO2R software. GO and KEGG pathways were analyzed using the DAVID tool. A protein-protein interaction network was then constructed, and hub genes were identified using Cytoscape software. Prognostic value analysis of hub genes was performed using GEPIA. A total of 144 up-regulated genes and 54 down-regulated genes were identified from the dataset GSE37318. These were mainly expressed during cell stress, DNA damage, cell cycle, senescence, apoptosis, oxidative stress, and in the p53 signaling pathway. A protein-protein interaction network consisting of 103 nodes and 376 edges was constructed, and the top 20 hub genes were identified. Of the top 10 hub genes, low expression levels of eight genes including MCM10, DLGAP5, FANCI, CENPA, CDC6, FBXO5, NCAPG, and DTL were related to poor overall survival (OS) in lung cancer patients (p<0.05). However, high levels of PCNA expression were also associated with poor OS in lung cancer patients (p<0.05). Ionizing radiation may induce both up- and down-regulation of genes in tumor-associated fibroblasts. These differentially expressed genes provide potential molecular markers for evaluating the efficacy of tumor radiotherapy, patient prognosis, risk of recurrence, and metastasis.

To observe the protective effect of compound raspberry seed powder on radiation induced spinal cord injury in mice. Fifty healthy adult male mice were randomly divided into five groups of ten: control group, model group, and different concentrations (low, medium, and high) of compound raspberry seed powder solution treatment group. The model group was given distilled water by gastric lavage and the treatment groups were given different concentrations of compound raspberry seed powder solution by gastric lavage. Except for the control group, the mice were irradiated with whole body X-ray at a dose of 4 Gy immediately after gastric administration on the 15th day after treatment. On the 3rd day after irradiation, the spinal cord tissues were taken for hematoxylin and eosin (HE) and Nissl staining to observe morphological changes and the expression of Fas and caspase-9 in spinal cord tissues was detected by immunohistochemistry(IHC). HE staining showed swelling and disorder of nerve fibers in the white matter of the spinal cord, atrophy, and disappearance of some neurons in gray matter, accompanied by an inflammatory reaction. Nissl staining showed that the Nissl body dissolved and neurons disappeared in the model group. IHC showed that the staining degree of Fas and caspase-9 in the model group was significantly higher than that in the control group (p<0.01). The staining degree of Fas and caspase-9 in compound raspberry powder solution treatment groups was lower than that in the model group and gradually decreased with the increasing concentrations(p<0.05). Compound raspberry seed powder can alleviate radiation-induced spinal cord injury and inhibit the overexpression of Fas and caspase-9 to inhibit apoptosis. With an increase in concentration, the protective effect is more obvious.

The irradiation sterilization process for medical devices must ensure that the maximum and minimum accepted doses for medical devices are between the maximum acceptable dose and the sterilization dose of the product. To ensure that the absorbed dose for each batch of medical devices meets the requirements, dose monitoring of the effect of each irradiation sterilization batch is required. This study adopts the statistical process control method to analyze monitored dose values and provides scientific quality management methods for medical device manufacturers and irradiation sterilization providers. The results show that the application of statistical process control methods can help to find abnormal fluctuations in time and to control the sterilization process to a stable state, thereby ensuring that the quality of medical device products is stable and reliable, as well as enhancing the predictability of quality management.

To develop efficient adsorption materials to improve the cure rate of heavy metal poisoning, we designed and prepared large size metal-organic framework (MOF) UiO-66-S films based on irradiation-grafting pretreated substrate, and investigated the selectivity of these films with multi-heavy metal ions in artificial plasma. The grafting density of maleic anhydride on a substrate was quantitatively measured by chemical titration and the effects of the radiation parameters on the grafting density were studied. The grafting density could be tuned from 0.10 to 75.80 nmol/cm² by changing the radiation parameters. The investigation of surface wettability and mechanical property proved that the irradiation-grafting process changed the surface wettability of maleic anhydride grafting substrate but did not affect its mechanical property. We prepared UiO-66-S films by in-situ growth and post-synthesis modification on the substrate with the grafting density of 14.94 nmol/cm² and characterized the film by attenuated total reflection flourier transformed infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope, which showed how the nanothickness continuous MOF film was obtained. The UiO-66-S films exhibited high selectivity to mercury ions in the artificial plasma with multi-ions co-existing; the removal ratio reached more than 50%. The adsorption process followed the pseudo-second-order kinetic equation. Moreover, the mercury ion-removal rate of the UiO-66-S films in the artificial plasma was faster than that in pure water.

In the radiotherapy of rectal cancer, the actual dose received by the patient's body always differs from the planned design due to setup errors. Twenty rectal cancer cases undergoing RapidArc treatment were selected. The treatment plan of the pCT images was transplanted to the scatter-corrected cone-beam computed tomography (CBCT) images. Then, the dose was calculated to generate the revised CBCT plan after the raw CBCT plan was corrected using the weekly setup error data. Finally, a paired t-test was used to compare the results of the dose calculation between the CBCT and pCT plans. This showed that the dosimetric parameter average values of D₂, D₉₈, D₅₀, CI, and HI in the target of the CBCT plan were lower than those in the pCT plan. The differences of 2.8%, 2.5%, 2.9%, 2.0%, and 4.4%, respectively, were statistically significant (p<0.001). The dosimetric parameter average values of D_mean, D₅, V₂₀, V₃₀, and V₄₀ in the small intestine of the CBCT plan were higher than those in the pCT plan. The differences of 3.0%, 3.1%, 2.5%, 3.1%, and 3.6%, respectively, were statistically significant (p<0.001). The dosimetric parameter average values of D_mean, D₅, V₂₀, V₃₀, and V₄₀ in the bladder of the CBCT plan were higher than those in the pCT plan. The differences of 3.0%, 1.8%, 0.9%, 3.2%, and 3.4%, respectively, were statistically significant (p<0.001). The difference between the left and right femoral heads was small (maximum difference: 0.3%, minimum difference: 0.1%); however, statistical significance was found (p<0.001). The comparative analysis indicates that the CBCT plan, based on scatter-corrected CBCT images combined with setup error data, provides a reference for the actual absorbed dose of each tissue in rectal cancer radiotherapy. These findings are useful for the quantitative evaluation of the therapeutic effect of radiotherapy for rectal cancer.

Using freshwater crayfish as raw materials, we developed a ready-to-eat crayfish by cleaning, cooking, curing, seasoning, and sterilization. The effects of the processing parameters of frying and sterilizing on the sensory quality, moisture, color, and texture characteristics of crayfish meat were studied. In addition, the effects of electron beam irradiation (4 kGy, 6 kGy, 8 kGy) and high-pressure steam (121 ℃, 20 min) sterilization on the colony counts of crayfish meat were compared. Results showed that, as frying temperature and frying time increased, the sensory value of crayfish meat did not change obviously. The moisture content decreased, and the hardness, elasticity, and chewiness increased. Electron beam irradiation had less effect on the texture and color of crayfish meat than high-pressure steam sterilization. With increasing absorption, the effect of irradiation sterilization became more pronounced. The crayfish could be stored for 6 d at 37 ℃ with colony counts of 7.4×10⁴ CFU/g when irradiated at an absorbed dose of 8 kGy.

The conventional solvothermal/hydrothermal reaction method is still a mainstream approach for synthesis of crystalline porous materials such as covalent organic frameworks (COFs). Their synthesis methods often require increased temperatures, closed systems with high pressures, and long reaction times. The provision of a mild and efficient energy input system for rapid synthesis of COFs is still challenging. We present a rapid room-temperature synthesis of two-dimensional imine-linked COFs through simple electron beam irradiation. Radiation energy is used as a new energy input mode instead of the conventional heating energy for the COF synthesis. Such synthesis by electron beam irradiation can be achieved at room temperature within minutes. In addition, the process can be adapted for large-scale production. The absorbed dose has crucial effects on the properties of the synthesized COFs, such as the crystallinity, Brunauer-Emmett-Teller surface area, morphology, and thermal stability. A series of successful syntheses of COFs, including not only the known rigid COFs, but also a series of new flexible COFs, demonstrates the generality of this approach.

Radioactive contamination of soil, caused by the nuclear industry and nuclear accidents, is currently one of the hot topics in the world. This paper reviewed the application of hyperaccumulators in the remediation of radioactive soil. The joint action of hyperaccumulators and earthworms was expounded. The application feasibility of earthworm in radioactive soil remediation was analyzed. The difficulties and research emphases of earthworms application in radioactive-soil remediation. The application prospect of earthworms in the remediation of radioactive soil was examined, providing reference for the establishment of nuclear pollution control technology in China.

The concept of radiation synthesis, its advantages and disadvantages compared with traditional polymer synthesis, the water absorption mechanism and swelling properties of super-absorbent resin (SAR) were introduced. There were many synthesis conditions that needed to be controlled, such as neutralization degree, absorption dose, and crosslinker dosage. Their influences on the swelling properties of poly(acrylic acid), super water-absorbent for medical use, were discussed in detail. In order to maximize the swelling properties, an electron beam radiation synthesis of high-performance, water-absorbent resin was designed. The uniform mixture was added into the atomization equipment, where mist droplets were polymerized through the ray curtain of the electron beam, to create gel particles. Surface crosslinking and sieving were subsequently carried out to form the water-absorbent resin. The effects of the absorption dose, the raw material, and dosage of the polymerization reaction on the swelling performance of SAR were studied. Absorbent resin product (2 g) was added into 50 mL of 0.9% NaCl solution and stirred at the speed of 600 r/min for 20 s; the time from the beginning of adding absorbent resin to the disappearance of the vortex was recorded as the absorption time. Regardless of the different polymerizing monomers, co-monomers, cross-linking agents, additives and surface cross-linking agents selected, the results showed that when the neutralization degree was around 65%~80% and the absorption dose was around 1~5 kGy, the absorption ratio of 0.9% NaCl solution to the absorbent resin product was about 70 g/g.

The damage in plant DNA induced by the naturally occurring radioactive gas radon were investigated here. For this, we chosed two common indicator plants, Tillandsiabrachycaulos and Tillandsia usneoides, as our model system. Leaf DNA damage was tested by the single cell gel electrophoresis method after a 72 h exposure of plants to radon at different concentrations. Increase in radon concentration led to a significant increase (p<0.05) in the comet DNA index (comet length, tail length, tail DNA, tail moment, and Olive tail moment), suggesting that Tillandsia suffered from radiation damage at the DNA level. However, DNA damage in T. brachycaulos with manually removed trichomes upon radon exposure at a concentration of 2 560 Bq/m³ was comparable to that in T. brachycaulos (with trichomes) exposed to 4 525 Bq/m³ of radon. This indicates that foliar trichomes present in these plants most likely act as a shield against pollutants, therefore alleviating radon-induced DNA damage.

A conjugated phenothiazine ketene dye (Phz-KT) with D?π?A?π?D structure was synthesized by the reaction between N-ethylphenothiazine and acetone. UV-vis spectroscopic studies showed that Phz-KT has strong absorption at 380~550 nm. A steady photolysis experiment showed that the dye has photobleaching properties under light irradiation. Considering Phz-KT dye as a photosensitive sensitizer and diaryl iodonium salt as an initiator, the epoxy ring-opening polymerization of bisphenol A epoxy resin E51 was investigated under irradiation from 460 nm and 520 nm LED light sources. It was found that the Phz-KT dye initiated epoxy resin polymerization via charge-transfer-sensitized diaryliodonium salt.

Hunan flavor leisure dried bean curd was irradiated by ⁶⁰Co γ rays at different absorbed doses (0 kGy, 3.1 kGy, 5.9 kGy, 8.6 kGy, 11.4 kGy), and the microbial survival rate, general nutrients, physicochemical properties, texture characteristics, and sensory quality were investigated. The results showed that ⁶⁰Co γ ray irradiation could effectively decrease the number of microbial survival in leisure dried bean curd, and the inhibition effect gradually increased with increasing absorbed dose. ⁶⁰Co γ ray irradiation could reduce the aerobic plate count and molds to below 10 CFU/g at an absorbed dose of 8.6 kGy. The absorbed doses (D₁₀) on aerobic bacterial count and molds of leisure dried bean curd were 1.82 kGy and 2.03 kGy, respectively. At absorbed doses less than 11.4 kGy, the ⁶⁰Co γ rays had a much weaker effect on the moisture, protein, and ash content of leisure dried bean curd as compared with the control group (p>0.05), but the fat content was significantly lower than that in the control sample after irradiation at different doses (p<0.05). There were no significant changes in the amino acid content of leisure dried bean curd as compared with that in the control sample (p>0.05) at different absorbed doses. The change in the acid value of leisure dried bean curd irradiated at different doses was different from that in the control group, but there was no significant correlation between the change in the acid value and the absorbed dose. The peroxidation value of leisure dried bean curd decreased with increasing absorbed dose and was significantly lower than that in the control sample (p<0.05). The irradiation dose had no significant effect on the texture properties of leisure dried bean curd, including hardness, cohesiveness, cohesiveness, chewiness, and springiness (p>0.05). Moreover, absorbed doses less than 8.6 didn't have any significant negative effect on the sensory quality. The results showed that ⁶⁰Co γ ray irradiation of leisure bean curd at doses less than 8.6 kGy would help retain its freshness during storage. The results of this research provide a reference for the application of irradiation technology in the leisure dried bean curd processing industry.

The finite-element multi-physics simulation software COMSOL was used to analyze the effects on the human body of a quadruple-circuit AC transmission line with a 1 000/500 kV dual voltage on the same tower. The magnetic induction intensity and induced electric field intensity in body tissues were calculated, and their maximum values in the human body were found to be 8.02 μT and 13.4 mV/m, respectively, under the conditions of 1 000 kV and 500 kV. These results were lower than the limits of the human electromagnetic (EM) exposure limits specified by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The case of a 1 000 kV or 500 kV single operation and nine typical phase sequence arrangements were analyzed, and the calculation results were also lower than the ICNIRP limits. Based on the results, the EM exposure generated by a quadruple-circuit AC transmission line with a 1 000 kV/500 kV dual voltage on the same tower will not pose a threat to human health.

Polyvinylidene difluoride (PVDF) and polyethylene glycol methyl methacrylate (PEGMA) were dissolved in N-methylpyrrolidone to form a homogeneous solution. The grafting reaction was initiated by γ-ray irradiation to prepare a modified polymer, PEGMA-g-PVDF. The analysis of the infrared spectra of PEGMA-g-PVDF before and after irradiation confirmed that the grafting reaction was effectively carried out. The degree of grafting (DG) of the irradiated product was determined by the quantitative analysis of F content before and after irradiation. Moreover, the effects of monomer concentration and absorbed dose on DG of the product were investigated. The results showed that DG increased firstly with the monomer concentration and absorbed dose in a certain range, and then decreased when exceeding the critical point. This paper also studied the thermal stability of the modified polymer through differential scanning calorimetry and thermogravimetric analysis. It was found that the melting point and thermal decomposition temperature of the modified polymer decreased with the increasing DGs. This result indicates that a higher DG reduces material’s thermal stability. Finally, according to the characteristics of homogeneous solution, the mechanism of graft reaction initiated by γ-ray irradiation was explained.

Three types of SiC fibers were prepared by polycarbosilane fibers using either pure solely oxidation curing method, an oxidation-thermal curing method, or electron beam radiation curing method. The chemical compositions of the three types of SiC fibers were analyzed using an element analyzer, and their heat resistance was studied using universal tensile testing machine; X-ray diffraction and scanning electron microscope were also employed for characterization. The results showed that the samples prepared by the solely oxidation and oxidation-thermal curing methods had higher oxygen contents, and the initial mechanical strength of the samples reached 2.8 GPa; however, the heat resistance temperature was approximately 1 200~1 300 °C; the oxygen content of SiC fibers prepared by the radiation crosslinking method was only approximately 1%, meaning that it was able to maintain a stable structure at a high temperature of 1 500 °C. This work showed that the heat resistance temperature of SiC fibers can be greatly improved by changing the curing mode, without changing the composition of the original preceramic polymers fiber.

To improve bolus reliability, we compared three different cavity sizes generated by different bolus thicknesses in patients by introducing intensity-modulated radiation therapy (IMRT) after radical mastectomy and analyzed the differences in dosimetry. Three IMRT plans—1, 2, and 3—were designed for cavity sizes greater than 10 mm, greater than 5 mm and less than 10 mm, and less than 2 mm, respectively. All three plans were compared to Plan 4 (bolus clinging to the skin ), which was conventionally used as a standard benchmark case. The present study analyzed the dose-volume histogram (DVH) and three-dimensional dose distribution profiles. The differences in dose distributions between the target area and the organ at risk were evaluated by statistical analysis on statistical package of social sciences (SPSS). The dose parameters of all the four plans satisfied the prescription dose requirements and no statistically significant differences were observed (p<0.05). However, the dose distribution map showed that the target areas in the cavities had high concentration areas and cold areas nearby the skin for both Plans 1 and 2. The DVH results showed reduced mean dose (D_mean) to the esophagus and trachea, percent volume received by the affected lung (V₃₀ ≥30 Gy), and percent volume received of the auxiliary structure ring (V₄₀ ≥40 Gy and V₄₅ ≥45 Gy) for Plans 3 and 4. The differences were statistically significant (p<0.05). Comparisons showed that Plan 3 reduced hot and cold spots around the target area, therefore reducing the risk of organ damage and indicating that it was the best plan in the present study. Plan 3 used a superposition method from 2 mm to 3 mm, which reduced the cavity size to less than 2 mm. It satisfies the compensation function of the bolus and avoids dosimetry error caused by the physical characteristics of the bolus, thus improving treatment quality.

This study aims at improving the irradiation processing capability of the ⁶⁰Co γ-radiation source and ensuring the quality of irradiated food. Thus, different stacking thicknesses and irradiation box structures were selected as process parameters, and the absorbed dose and unevenness of irradiated foods with different densities were measured and analyzed. The results showed that the spatial dose field distribution was symmetric with the center point of the source plate, symmetrically distributed above and below the center, and that the absorbed dose at the center was the highest. With increasing distance from the center, the absorbed dose decreased, and unevenness was observed. The greater the stacking thicknesses of products with the same density, the higher was the unevenness. There was no obvious effect of stacking thickness on low-density products. Combined with the dose distribution of the empty field, when the unevenness was greater than 1.4, the main contradiction was transformed into the influence of stacking thickness, mainly because of the inhomogeneity of the outer and central surfaces. At this time, in order to increase the utilization rate of γ-rays, the minimum dose and loading amount should be determined for the product with a density of less than 0.36 g/cm³, consider thinning instead of tiling for the product with a density of more than 0.36 g/cm³. For products with a density of 0.3 g/cm³, the spatial distribution of the irradiation field at a height of 5 cm from the bottom of the irradiation box was better than that of the punch. In addition, the γ-ray utilization of the irradiation box height and punch increased by 8.26% and 8.30%, respectively, compared with those for the original irradiation box. Therefore, the loading capacity and the structure of the irradiation box can be considered to reduce the minimum absorbed dose of food, thereby improving the energy utilization rate and production efficiency of γ-rays during food irradiation.

The error caused by reflective light in ultraviolet (UV) irradiance measurement was analyzed, and a countermeasure to prevent this reflection error was proposed, which involved preventing reflection beams from reaching the probe. By setting a plate with a slot between the light source and the probe, the irradiance from the light source can be accurately and directly obtained; and with a baffle, the irradiance from the reflection beams can be accurately derived. The summation of the irradiance from the light source (45.7 μW/cm²) and the reflection beams (5.3 μW/cm²) matches the irradiance (51.0 μW/cm²) measured without anti-reflection fabrication. Setting a plate prevents the reflection error, and makes UV measurements in a small space feasible and cost effective, without sacrificing accuracy. The formulas for the calculation of the key parameters in designing the measurement system equipped with anti-reflection fabrication were derived.

This paper evaluates the effects of the total ionizing dose (TID) radiation 0.35 μm domestic SiGe BiCMOS devices under different bias conditions. ⁶⁰Co gamma irradiation was performed at a high dose rate of 1 Gy(Si)/s. The results show that the SiGe BiCMOS devices enable excellent tolerance to total ionizing effect, reaching multi-kGy(Si) total ionizing dose tolerance, and the base currents are more sensitive to radiation. Under different bias conditions, when the total dose accumulated to 12 kGy(Si), the reverse bias irradiated damage is the largest, followed by the zero bias, and the forward bias irradiation presents minimum damage. We found that the main mechanism of TID is that the high dose rate radiation and the edge electric field introduced by the bias conditions influences the oxide trap charges and interface state generation in the oxide layer, which leads to an increase in the radiation sensitive zone of the base pole and an increase in the base current, thus reducing the current gain of the device.

In this study, we aimed to explore the biological effect and photosynthetic response mechanism of ^{heavy-ion irradiation on Dunaliella salina. Dunaliella salina was treated with different doses (0~320 Gy) of heavy-ion irradiation.The cell biomass, chlorophyll fluorescence parameters, and main photosynthetic pigments of progenies from irradiated Dunaliella salina cells were systematically measured and analyzed within 10 days of treatment. The results showed a significant increase in the biomass of cells that underwent heavy-ion irradiation at 90 Gy, 240 Gy, and 320 Gy doses compared with non-irradiated Dunaliella salina cells. In particular, the maximum biomass of irradiated cells was 1.78-fold greater than of non-irradiated cells at 240 Gy. The chlorophyll fluorescence imaging system, Water-PAM, was used to analyze the chlorophyll fluorescence parameters, including photochemical efficiency of photosystem II (F_v/F_m), actual photosynthetic activity (ΦPSII), and non-photochemical quenching capacity (NPQ) of the cells after irradiation. The results indicated that 90 Gy, 240 Gy, and 320 Gy doses notably increased the photosynthetic efficiency of Dunaliella salina. The 240 Gy dose-irradiated algal cells exhibited activated photoprotection systems more rapidly as compared to cells irradiated at other doses. Additionally, the β-carotene content of the algal cells after irradiation was measured using UV spectrophotometry. The results revealed that β-carotene production increased compared with non-irradiated Dunaliella salina cells, by 1.3 and 1.1 times with 240 Gy and 320 Gy, respectively. To our knowledge, this study investigated the dose and time response to heavy-ion irradiation on Dunaliella salina mutagenesis for the first time, and provided a preliminary theoretical and experimental basis for the response mechanism of the photosynthetic system to heavy-ion irradiation.}

To improve the wall-broken rate and polysaccharide content of Ganoderma lucidum spore powders, a combined treatment of γ ray irradiation and ball milling technique was used. Two-factor tests were conducted using the absorbed dose and the ball milling time as the test factors. The morphology and molecular structure of the Ganoderma lucidum spores were characterized using scanning electron microscope and Fourier transform infrared spectrometer tests under different treatment conditions. The results showed that when the absorbed dose was higher than 4.892 kGy, or the ball milling time was higher than 1 minute, the absorbed dose and ball milling time had significant effects on the wall-broken rate and the polysaccharide content of the Ganoderma lucidum spore powders, with the ball milling time having a greater effect. In addition, there was an interaction between the two pretreatment methods, which significantly affected the wall-broken rates and the polysaccharide contents of the Ganoderma lucidum spore powders. Furthermore, the optimal wall-broken rate of 97.18% and polysaccharide mass fraction of 13.230 mg/g were achieved when the Ganoderma lucidum spore powders were irradiated at 15.231 kGy with a ball milling time of 5 min. In addition, under these treatment conditions, the complete oval structure of the Ganoderma lucidum spores was almost completely broken. A small spike was observed at 1 456 cm^-1, and a double peak was observed at 1 652 cm^-1, which were completely different from the unbroken wall spores.

This study aimed to improve the ability to detect the effects of radiation-associated genetic damage and establish a rapid and simple method for estimating biological dose. Radiation-sensitive genes were selected as biodosimeters from Pig-a, Gadd45α, and Hprt, based on their mRNA expression level changes. RT-qPCR was used to assay the relative expression level of the target genes in peripheral blood samples of healthy non-radiation (control group) and radiation workers (exposed group) and their relative expression level average, fluctuation range and variation coefficient of the background expression were counted. Peripheral blood samples of healthy adults were irradiated with different X-ray doses of 0 Gy, 0.10 Gy, 0.25 Gy, 0.50 Gy, 1.00 Gy, 2.00 Gy, and 5.00 Gy, respectively. 6 h later, the relative expression of the target genes was examined using RT-qPCR and the binomial regression curve analysis was performed to analyze the quantitative effect relationship. The results showed that Pig-a and Gadd45α expressions had small background level differences in the control group; Hprt had large background level differences and its variation coefficients were greater than 20%. The Hprt expression level in the control group was higher than that in the exposed group; Gadd45α and Pig-a expressions in the control group were lower than that in the exposed group (p<0.05). There was a dose-effect relationship between the Gadd45α and Pig-a expression levels and irradiation doses, indicating that the Pig-a and Gadd45α expression level changes could be used as potential biodosimeters.

In this report, we performed numerical simulation of electromagnetic exposure in rats using elliptically polarized waves as the source. By comparing the whole-body specific absorption rate (WBASAR) of electromagnetic exposure for multiple incident directions, it was determined that the WBASAR of elliptically polarized waves change with the polarization state, and is affected by the incident direction and the direction of rotation. Comparing this result to the irradiation results for linearly polarized waves travelling in the same direction, it was determined that the WBASAR results for electromagnetic exposure for these two cases are different under the same incident power. Moreover, the discrepancy presents different characteristics depending on the incident direction of the wave source and the relative positional changes associated with the posture of the rat. In addition, factors such as the polarized nature of the wave source, the irradiation method, and the rat itself, also caused large differences in the distribution of the average specific absorption rate of important tissues in rats. Therefore, considering the exposure results for linearly and non-linearly polarized waves, the exposure dose can be more comprehensively evaluated. The calculations presented in this report provide a method and supplemental data for the evaluation of electromagnetic exposure dose in animals.

After a nuclear accident, rescue operation path planning in the radioactive environment is an important part of the emergency response decision matrix. Considering the environmental characteristics of the radiation field, a method based on coupling the radiation field dose factor and ant colony optimization was used to plan the path under simulated time and dose numerical constraints. Using the typical radiation region of a nuclear power plant as input, equipment inspection path planning in the radiation field was simulated. The results show that the method in this paper can provide decision support for rapid response in a nuclear emergency.

Ethylene-tetrafluoroethylene copolymers (ETFE) were aged at various absorbed doses (60 kGy, 120 kGy, and 180 kGy), and then, they were estimated and characterized by carbon residual rate, tensile test, thermal elongation test, volume resistivity analysis, and Fourier transform infrared (FTIR) spectroscopy. The results showed that the carbon residual rate of these aged samples increased with the absorbed dose while the thermal elongation decreased. With increasing absorbed dose and aging time, the tensile properties of the aged ETFE copolymer samples degraded, which could be attributed to chain breakage. Furthermore, the formation of crosslinking networks led to a change in the volume resistivity of the aged samples. The aging sample with an absorbed dose of 120 kGy showed the highest value and the best insulation performance. In addition, the FTIR results indicated that with increasing aging time, the amorphous structure of the aged samples first increased and then decreased.

In order to improve the properties of small organic molecules, such as poor solubility and easily falling off, a novel water-soluble polymer was synthesized. First, a fluorescent functional monomer (BSA) was synthesized using 4,4′-sulfonyldiphenol and methacryloyl chloride. Then, a fluorescent material, poly(BSA-co-AM-co-NIPAM) (PBAN), was synthesized through free-radical polymerization among N-isopropylacrylamide (NIPAM), acrylamide (AM), and acryloxydiphenylsulfone (BSA). The structure of the polymer was confirmed by ¹H nuclear magnetic resonance and Fourier transform infrared spectroscopy analyses. The absorption and emission spectra of PBAN were obtained using a fluorescence spectrometer. The results indicated that PBAN showed strong fluorescence, with high stability and safety, and that the fluorescence intensity decreased with increasing temperature. This polymer showed high sensitivity to 4-NP, with a detection limit of 2.8 × 10^-8 mol/L. A linear relationship for fluorescence detection was obtained in the range of (5.0~24.9) × 10^-8 mol/L. Therefore, PBAN is expected to find use as a sensitively responsive probe for 4-NP detection..