Different Types Of Radiation Research Articles

Impact of Salt on Thermal Stability and Dose Response of the Fricke-XO-Pluronic F-127 3D Radiotherapy Dosimeter.

Fricke-XO-Pluronic F-127 has recently been proposed as a 3D dosimeter for radiotherapy. It contains the typical ingredients of the Fricke ionizing radiation dosimeter, which are embedded in a physical gel of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic F-127). The main reactions upon irradiation are the conversion of Fe+2 to Fe+3 and the formation of a colored complex with XO ([XO-Fe]+3). The study attempts to optimize the dosimeter in terms of its solution-to-gel transition temperature. In order to lower this temperature, the use of NaCl salt has been proposed. The new composition was characterized in order to obtain information on its thermal performance, storage stability, dose response to irradiation with a medical accelerator emitting different types of radiation, and tissue equivalence. The results obtained show an improvement in the sol-gel transition temperature and dose sensitivity compared to the composition without NaCl and broaden the knowledge of the Fricke-XO-Pluronic F-127.

Ultraviolet B modulates gamma radiation-induced stress responses in Lemna minor at multiple levels of biological organisation

Elevated levels of ionizing and non-ionizing radiation may co-occur and pose cumulative hazards to biota. However, the combined effects and underlying toxicity mechanisms of different types of radiation in aquatic plants remain poorly understood. The present study aims to demonstrate how different combined toxicity prediction approaches can collectively characterise how chronic (7 days) exposure to ultraviolet B (UVB) radiation (0.5 W m−2) modulates gamma (γ) radiation (14.9, 19.5, 43.6 mGy h−1) induced stress responses in the macrophyte Lemna minor. A suite of bioassays was applied to quantify stress responses at multiple levels of biological organisation. The combined effects (no-enhancement, additivity, synergism, antagonism) were determined by two-way analysis of variance (2 W-ANOVA) and a modified Independent Action (IA) model. The toxicological responses and the potential causality between stressors were further visualised by a network of toxicity pathways. The results showed that γ-radiation or UVB alone induced oxidative stress and programmed cell death (PCD) as well as impaired oxidative phosphorylation (OXPHOS) and photosystem II (PSII) activity in L. minor. γ-radiation also activated antioxidant responses, DNA damage repair and chlorophyll metabolism, and inhibited growth at higher dose rates (≥20 mGy h−1). When co-exposed, UVB predominantly caused non-interaction (no-enhancement or additive) effects on γ-radiation-induced antioxidant gene expression, energy quenching in PSII and growth for all dose rates, whereas antagonistic effects were observed for lipid peroxidation, OXPHOS, PCD, oxidative stress, chlorophyll metabolism and genes involved in DNA damage responses. Synergistic effects were observed for changes in photochemical quenching and non-photochemical quenching, and up-regulation of antioxidant enzyme genes (GST) at one or more dose rates, while synergistic reproductive inhibition occurred at all three γ-radiation dose rates. The present study provides mechanistic knowledge, quantitative understanding and novel analytical strategies to decipher combined effects across levels of biological organisation, which should facilitate future cumulative hazard assessments of multiple stressors.

ASSESSMENT OF RADIOACTIVE ELEMENTS IN THE RAMUNICKEL AND YANDERA MINING SITES OF PAPUA NEW GUINEARELATED TO RADIATION POLLUTION OF THE ENVIRONMENT

Radioactive elements present in the soil emit radiation of different types that poses a threat for human life. Mining waste and residues create environmental pollution and these have to beproperly monitored and managed. Measurement of ambient radiation doses and determination of radio nuclides in the mining waste and soil were performed in six riverside locations of Ramu Nickel and Yandera mining sites in Usino Bundi district of Madang and in a nearby place, Lae, in Morobe Province, Papua New Guinea. The average dose rate in air in the mining sites and in Lae have been calculated and it was observed that the annual dose rate in the mining site varies from0.9 mSv/y to 1.1 mSv/y whereas in Lae, it is only 0.78 mSv/y. The outdoor dose rate was found to vary from 126.8 mGy/y to 155.4 mGy/y and the indoor dose rate was found to vary from 507.2 mGy/y to 621.7 mGy/y in the mining sites. The soil samples were analyzed using NaI(Tl) gamma rayspectrometer. Radioactive elements Ca45, I129,Hg203, Cr51, Au198, Fe59, Co60, Ti201, Cd109, Bi214 and Sc47were observed to be slightly higher in the mining area compared to that observed in nearby sites. Though radioactivity level in the mining sites is slightly higher, it is well below the global standards.

Phytochemical Based Nano Design for Cancer: A Recent Update

Despite exponential advancements in medical research, various types of cancer are increasing day by day and becoming a leading cause of mortality worldwide. The worldwide cancer burden has increased to 19.3 million new cases and 10 million cancer deaths in 2020. Changes in food habits, lifestyle, different types of food additives, synthetic chemicals, environmental pollutants, different types of radiation, and limited physical activities have led to a severe increment in this disease. Healthy nutritive foods and phytochemicals play an essential role in supporting the immune system, which is beneficial in combating various types of cancer. Phytochemicals are natural bioactive non-nutrient compounds derived from various plant sources, reducing the risk of major chronic diseases. It can be easily classified and categorized into different groups based on its chemical nature and mode of biological action. These bioactive compounds are effective against various types of cancers. Recently the role of several novel phytochemicals and nanoformulations has been explored and extensively applied in cancer therapeutics. This review provides insight into various traditional phytochemicals and novel nanoformulations used in cancer management.

Hawking radiation of charged massive particle and tunneling from Kerr–Newman–de Sitter black hole

The semiclassical tunneling technique proposed by Parikh and Wilczek to study Hawking radiation of static and stationary black holes has been extensively used to investigate the Hawking radiation of different types of black holes. In this paper, the geodesic equation of charged massive particle and the massless particle are obtained by using the Lagrangian analysis. The geodesic equations of charged massive particle and massless particle are determined uniformly and consistently. Based on the geodesic equation, the Hawking radiation of the charged massive particle is investigated near the event horizon of Kerr–Newman–de Sitter black hole. By finding the imaginary part of the action of charged massive particle, the Hawking temperature and the tunneling probability of charged massive particle across the event horizon of KNdS black hole are obtained. The finding of this paper is a development for Parikh–Wilczek’s tunneling technique.

Abstract 213: Assessing the role of X-ray radiation in combination with a DNA-PK inhibitor on cellular activity and adhesion using an in vitro HER2-positive breast cancer model

Abstract Introduction: Breast cancer (BC) is the most common cancer for women regardless of ethnicity, and the leading cause of cancer-related deaths in women. Radiation therapy (XRT) plays a vital role in multidisciplinary treatment approaches. Although XRT has been found to reduce breast cancer recurrence and mortality rate, like all other therapeutics, XRT contains some risks. Radiation can increase the mortality rate due to the risk of ischemic heart diseases. As part of an overall effort to understand the interaction between different types of radiations (e.g., radiopharmaceutical therapy (RPT) with β or α-particle emitters) and DNA double-strand break repair (DSB) repair pathways, we observed that impairment of DNA DSB by DNA-PKcs inhibitor (NU7441) fragmented HER2-positive BC spheroids in the presence of XRT. This could be possibly due to the modulation of cellular adhesion protein mediated by DNA-PK inhibition. In this study, we aim to assess the spheroids fragmentations and also measure the cell viability and levels of a cell adhesion protein, β1-integrin in irradiated HER2-positive monolayer cells, to get a mechanistic view for XRT and NU7441 combinatorial action so as to compare with β- or α-emitter RPT. Methods: In brief, NT2.5 BC spheroids were formed in agarose-coated 96-well plates. For both spheroids and monolayer cells, half of the media was replaced with fresh media containing 1 nM-5μM of NU7441 every other day. A colorimetric cell viability kit was used to measure cell viability and western blot analysis was performed to measure the β1-integrin level, which was normalized against β-actin. Results: Microscopic analysis suggested that XRT increased spheroid fragmentations in the presence of NU7441 compared to the XRT alone. Interaction between XRT and NU7441 (6.68% of the total variation, P<0.0001) was found for the cell viability data, where XRT (74.07% of the total variation, P<0.0001) and NU7441 (5.07% of the total variation, P<0.0001) both regulated cell viability on their own. Western blot data suggest that β1-integrin level was reduced for 8 Gy XRT and 5 μM NU7441 combination compared to the no XRT and vehicle combination. Moreover, 2-way ANOVA analysis revealed that XRT plays a role to regulate the β1-integrin level in NT2.5 monolayer cells (57.61% of the total variation, P<0.0001). Conclusion: XRT increased BC spheroids fragmentations when DNA damage was inhibited by a small molecule inhibitor. XRT and NU7441 both regulated NT2.5 cell viability with an interaction between them. Furthermore, XRT reduced β1-integrin level in monolayer NT2.5 cells. The XRT and NU7441 combination may induce fragmentations by decreasing cell viability and adhesion proteins. Future studies assessing the mechanisms of XRT and DNA PK inhibitor in BC spheroids and in vivo are warranted to confirm these results. Citation Format: Mahmud Hasan, Ioanna Liatsou, George Sgouros. Assessing the role of X-ray radiation in combination with a DNA-PK inhibitor on cellular activity and adhesion using an in vitro HER2-positive breast cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 213.

Restoration of the Indicator Properties of Whole-cell Luminescent Biosensors

Whole-cell biosensors are widely used to produce medical diagnostic tests, but in the long term, they tend to lose their indicator properties. Consequently, it is crucial to find ways to restore these properties and prolong the shelf life of the tests. Here, we propose to use electromagnetic radiation with optimally selected parameters of frequency, power, and exposure time. The impact of radiation parameters on biosensor luminescence was studied as well as the effects of different types of radiation coming from laser sources (λ = 875nm), a LED source (λ = 850 ÷ 890nm), and microwave units (at frequencies 42.22, 53.53, 61.18 и 34 ÷ 38GHz). IR treatment resulted in dose-dependent suppression of biosensor luminescence. The luminescence level when exposed to microwave radiation depends on the radiation time and frequency. Also, it has been found that optimal selection of the main radiation parameters enables to restore indicator properties partially lost by biosensors during storage. We explain the mechanism responsible for the sensitizing effect of radiation, which implies the polarization of solvent dipoles and changes in mobility of acceptor molecules. This, in turn, leads to a shift in the chemical equilibrium states and triggers a cascade of biochemical reactions that lead to restoration of the lost indicator properties of biosensors. The study of antagonistic activity has revealed that restored biosensors provide reliable test results after the expiration of their warranty period.

Detection of hidden oxygen interstitials in neutron-irradiated corundum crystals

An α-Al2O3 (corundum) possesses unique optical, electrical and mechanical properties, demonstrates high tolerance to heavy irradiation and, in particular, is in a short list of candidates for optical/diagnostics windows in advanced fission and forthcoming fusion (DEMO) reactors. However, material functionality is strongly affected by structural defects induced by radiation of different types. Optical and magnetic characteristics of Frenkel defects (interstitial-vacancy pairs) as well as the processes of their thermal annealing (radiation damage recovery) have been investigated by means of optical absorption and the EPR methods in α-Al2O3 single crystals exposed to fast neutrons with fluence of 6.9 × 1018n/cm2. For the first time in metal oxides, a single oxygen interstitial, which is not adjacent to any other imperfection, has been detected. The analysis of the EPR spectra/parameters testifies that this interstitial forms with a regular oxygen ion a superoxide ion O2−, stabilized by a trapped hole. The interstitial becomes mobile above 500 K and recombines with a complementary oxygen vacancy that is a part of electronic F+ or F centers. The thermal annealing kinetics of the F and F+ centers has been theoretically analyzed in terms of interrelated diffusion-controlled recombination reactions of radiation defects. The analysis indicates that both, negatively charged and neutral oxygen interstitials (relevant absorption bands at 5.6 and 6.5 eV, respectively) co-exist in similar concentrations.

Comparative characteristics of morphological changes in the pancreas under different types of irradiation in the experiment

The aim of the study was to conduct a comparative characteristic of the morphological changes in the pancreas with different types of irradiation in the experiment. It has been established that a comparative description of the data of the first (acute irradiation) and the second group (chronic irradiation) of white outbred rats revealed 11 morphological signs indicating pathological changes in the pancreatic parenchyma, in terms of the intensity of occurrence of which differences were found that related to such morphological changes as atrophic changes in the interlobular excretory duct, stromal fatty degeneration, which were visualized only in animals of the first group. Plasma impregnation of vessel walls, atrophic changes in the parenchyma, atrophy of the islets of Langerhans were not found in all animals of the second group, while in the first group they were visualized in all rats. Comparative analysis shows that pathological changes in the pancreatic parenchyma of animals treated with acute irradiation were more intense, and more pathological signs were seen compared to chronic irradiation.

Development of a phoswich detector composed of ZnS(Ag) and YAP(Ce) for astatine-211 imaging

For the research on alpha emitters used for targeted alpha particle therapy such as astatine-211 (211At), alpha particle as well as X-ray imaging are required for autoradiography and phantom imaging or in vivo imaging of small animals. Consequently, two imaging detectors for different types of radiations are required in such research. However, preparing two types of imaging detectors needs cost and space. If a single imaging detector could image alpha particles as well as X-rays for 211At, it would be an advance in the imaging research for targeted alpha particle therapy. Consequently, we developed a detector that can be used for both alpha particle and X-ray imaging. The developed imaging detector is a phoswich type made of a ZnS(Ag) sheet and a cerium doped YAlO3 (YAP(Ce)) plate optically coupled to each other with a 1-mm-thick light guide between scintillators. These scintillators were optically coupled to a 1-inch-square position-sensitive photomultiplier tube (PSPMT) to form an imaging detector. The ZnS(Ag) sheet detects alpha particles while the YAP(Ce) plate detects X-rays from 211At. Due to the pulse height difference between alpha particles and X-rays, a different high voltage was supplied to the PSPMT for alpha particle and low-energy X-ray detection. Discrimination between alpha particles and X-rays were conducted by pulse height as well as pulse shapes of ZnS(Ag) and YAP(Ce). The intrinsic spatial resolution for 5.5-MeV alpha particles was better than 0.6 mm the full width at half maximum (FWHM), while that for 60-keV gamma photons was ∼1.2 mm FWHM. Energy resolution for 5.5-MeV alpha particles was 60% FWHM, while that for 60-keV gamma photons was 25% FWHM. With a 4-mm-thick, 0.6-mm-diameter parallel hole collimator mounted on the detector, the system spatial resolution for 60-keV gamma photons was ∼2 mm FWHM within 5 mm from the collimator surface, and its sensitivity was 0.5%. An image of the 211At alpha particle distribution of a sliced kidney as well as an X-ray image of a paper soaked with 211At solution could be obtained. We conclude that the developed detector is promising for single-detector imaging of alpha particles as well as X-rays from 211At.

Osteoconductive Effect of a Nanocomposite Membrane Treated with UV Radiation.

Modulation of the bio-regenerative characteristics of materials is an indispensable requirement in tissue engineering. Particularly, in bone tissue engineering, the promotion of the osteoconductive phenomenon determines the elemental property of a material be used therapeutically. In addition to the chemical qualities of the constituent materials, the three-dimensional surface structure plays a fundamental role that various methods are expected to modulate in a number of ways, one most promising of which is the use of different types of radiation. In the present manuscript, we demonstrate in a calvarial defect model, that treatment with ultraviolet irradiation allows modification of the osteoconductive characteristics in a biomaterial formed by gelatin and chitosan, together with the inclusion of hydroxyapatite and titanium oxide nanoparticles.

Comparative Study of γ- and e-Radiation-Induced Effects on FBGs Using Different Femtosecond Laser Inscription Methods.

This work presents an extensive, comparative study of the gamma and electron radiation effects on the behaviour of femtosecond laser-inscribed fibre Bragg gratings (FBGs) using the point-by-point and plane-by-plane inscription methods. The FBGs were inscribed in standard telecommunication single mode silica fibre (SMF28) and exposed to a total accumulated radiation dose of 15 kGy for both gamma and electron radiation. The gratings’ spectra were measured and analysed before and after the exposure to radiation, with complementary material characterisation using Fourier transform infrared (FTIR) spectroscopy. Changes in the response of the FBGs’ temperature coefficients were analysed on exposure to the different types of radiation, and we consider which of the two inscription methods result in gratings that are more robust in such harsh environments. Moreover, we used the FTIR spectroscopy to locate which chemical bonds are responsible for the changes on temperature coefficients and which are related with the optical characteristics of the FBGs.

Analysis of the possibility of irradiation-induced coloring of topaz in the WWR-K reactor

Nowadays, radiation technologies are widely used in industry, medicine and other fields. One of the particular cases of application of such technologies is the irradiation-induced coloring of topaz. As a result of the application of this technology, colorless topaz acquires a more noble, respectively, economically advantageous color. For this, different types of radiation can be used. In the case of irradiation-induced coloring of topaz using neutrons, it is necessary to formation optimal conditions for irradiation of topaz. First of all, in the topaz irradiation zone it is necessary to formation a "hard" neutron spectrum not only for the formation of color centers, but also to reduce the residual radioactivity in the topaz. In this work, the possibility of implementing the technology of irradiation-induced coloring of topaz in the WWR-K research reactor was evaluated. For this, the energy distribution of neutrons in the central and peripheral irradiation positions of the WWR-K reactor was determined. On the basis of the obtained values, the time to reach the target neutron fluence (1018 cm-2) was estimated. The influence of the ratio of the flux of fast to thermal neutrons on the activation of natural impurities in topaz is shown. The results of trial irradiation of topazes in the WWR-K reactor without formation special conditions are presented. Ways to optimize the conditions for irradiation of topazes in the WWR-K reactor in order to improve the economic efficiency of the work were proposed.

Verification and Improving the Heat Transfer Model in Radiators in the Wide Change Operating Parameters

Laboratory measurements and analyses conducted in a wide range of changes of water temperature and mass flow rate for different types of radiators allowed to provides limitations and assessment of the current radiators heat transfer model according to EN 442. The inaccuracy to determinate the radiator heat output according to EN 442, in case of low water mass flow rates may achieve up to 22.3% A revised New Extended Heat Transfer Model in Radiators NEHTMiRmd is general and suitable for different types of radiators both new radiators and radiators existing after a certain period of operation is presented. The NEHTMiRmd with very high accuracy describes the heat transfer processes not only in the nominal conditions—in which the radiators are designed, but what is particularly important also in operating conditions when the radiators water mass flow differ significantly from the nominal value and at the same time the supply temperature changes in the whole range radiators operating during the heating season. In order to prove that the presented new model NEHTMiRmd is general, the article presents numerous calculation examples for various types of radiators currently used. Achieved the high compatibility of the results of the simulation calculations with the measurement results for different types of radiators: iron elements (not ribbed), plate radiators (medium degree ribbed), convectors (high degree ribbed) in a very wide range of changes in the water mass flow rates and the supply temperature indicates that a verified NEHTMiRmd can also be used in designing and simulating calculations of the central heating installations, for the rational conversion of existing installations and district heating systems into low temperature energy efficient systems as well as to directly determine the actual energy efficiency, also to improve the indications of the heat cost allocators. In addition, it may form the basis for the future modification of the European Standards for radiator testing.

Sequential ion-electron irradiation of zirconium carbide ceramics: Microstructural analysis

Zirconium Carbide (ZrCx) was irradiated with 10 MeV Au3+ ions to a dose of 10 displacements per atoms (dpa) and subsequently with 100 and 300 keV electrons in a transmission electron microscope (TEM). After ion irradiation, dislocation loops were observed in the microstructure and an increase in the number of carbon vacancies was revealed by Raman spectroscopy. Grazing incidence X-ray diffraction (GIXRD) analysis showed that neither amorphization nor oxidation occurred during ion irradiation of the specimen. Subsequent electron irradiation of the pre-implanted ZrCx foil led to formation of nanosized tetragonal ZrO2 precipitates (5−10 nm diameter) on the surface of the TEM lamella. The formation of the new oxide phase was not related to the electron beam-induced heating of the specimen, but to electron stimulated oxidation caused by the residual oxygen inside the transmission electron microscope. Changes in size and density of ZrO2 crystallites were observed between the pristine and ion irradiated ZrCx regions following electron irradiation, suggesting that the initial microstructure of the ZrCx substrate played a key role in the nucleation and growth of the oxide islands. The obtained results provide insights into the microstructural response of ZrCx to different types of radiation and the inadvertent effects of the electron beam during TEM analysis of in-situ and ex-situ ion irradiated ZrCx. Additionally, the findings of this work suggest a method to prepare local ZrO2 nanoprecipitates within ZrCx grains by selective electron beam irradiation.

Preliminary analysis of the benefits of different irradiation types on patients with postoperative locoregional recurrence of esophageal cell squamous carcinoma.

To explore the benefits of different types of irradiation on patients with postoperative locoregional recurrence (LRR) of thoracic esophageal squamous cell carcinoma (ESCC). We analyzed the medical records of 344 patients with recurrent esophageal cancer (EC) at the Fourth Hospital of Hebei Medical University. All patients met an inclusion criteria that included having postoperative LRR (without distant metastasis), and having received either chemotherapy, radiotherapy, or chemoradiotherapy after LRR. Patients either received elective nodal irradiation (ENI) or involved field irradiation (IFI), with a stratified analysis performed on both groups. SPSS 19.0 software (IBM Corporation, Armonk, NY USA) was then used for statistical analysis. The median overall survival time of all patients after surgery was 33 months [95% confidence interval (CI): 28.3-37.7 months]; the median overall survival time of patients after recurrence after radiotherapy was 12.8 months (95% CI: 11.3-14.3 months). There were 276 cases (80.2%) of single local recurrence after surgery, and 68 cases (19.8%) of multiple local recurrence (≥2). The results of our multivariate analysis showed that the patient's gender, log odds of positive lymph nodes (LODDS), and the number of courses of chemotherapy were all independent factors affecting the patient's prognosis (P=0.003, P<0.001, and P<0.001). The results of stratified analysis showed that patients with esophageal lesion length <5.0 cm, stage N0, ≤9 surgically dissected lymph nodes, no positive regional lymph node metastasis (LNM), and LODDS ≤0.030 could benefit from ENI treatment (X2=4.208, P=0.032; X2=6.262, P=0.012; X2=10.359, P=0.001; X2=6.327, P=0.012; X2=6.026, P=0.014); and patients with ≥16 surgically dissected lymph nodes could benefit from IFI treatment (X2=4.429, P=0.035). Chemotherapy, radiotherapy, and chemoradiotherapy are all effective modes of treatment for patients with postoperative LRR of EC. Patients with shorter esophageal lesions determined by preoperative esophagography, earlier postoperative pathological N staging, lower LODDS scores, and fewer surgically dissected lymph nodes might benefit more from ENI treatment than from IFI. However, patients with a larger number of lymph nodes dissected during surgery might benefit more from IFI treatment. To further confirm this study's conclusions, multiple prospective studies should be undertaken in the future.

Development of a DNA damage model that accommodates different cellular oxygen concentrations and radiation qualities

Research regarding cellular responses at different oxygen concentrations (OCs) is of immense interest within the field of radiobiology. Therefore, this study aimed to develop a mechanistic model to analyze cellular responses at different OCs. A DNA damage model (the different cell oxygen level DNA damage [DICOLDD] model) that examines the oxygen effect was developed based on the oxygen fixation hypothesis, which states that dissolved oxygen can modify the reaction kinetics of DNA-derived radicals generated by ionizing radiation. The generation of DNA-derived radicals was simulated using the Monte Carlo method. The decay of DNA-derived radicals due to the competing processes of chemical repair, oxygen fixation, and intrinsic damaging was described using differential equations. The DICOLDD model was fitted to the previous experimental data obtained under different irradiation configurations and validated by calculating the yields of DNA double-strand breaks (DSBs) after exposure to 137 Cs as well as cell survival fractions (SFs) using a mechanistic model of cellular survival. Moreover, we used the DICOLDD model to calculate DNA DSB damage yields after irradiation with 0.5-50MeV protons. Generally, DSB yields calculated after exposure to 137 Cs at different OCs correspond to statistical uncertainties of previous experimental results. Calculated SFs of CHO and V79 cells exposed to photons, protons, and alpha particles at different OCs generally concur with those obtained in previous studies. Our results demonstrated that the variation in DSB yields was less than 10% when the cellular OC decreased from 21% to 5%. Additionally, DSB yields changed drastically when OC dropped below 1%. We developed a DNA damage model to evaluate the oxygen effect and provide evidence that a reaction-kinetic model of DNA-derived radicals induced by ionizing radiation suffices to explain the observed oxygen effects. Therefore, the DICOLDD model is a powerful tool for the analysis of cellular responses at different OCs after exposure to different types of radiation.

Cell response analysis to synchrotron radiation X-ray microbeam cytoplasm limited irradiation

The cells responsible for cancer start their journey much like any other in the body. However, they grow uncontrollably through the body as a result of the accumulation of certain mutations. If left unchecked, cancer will impact on a number of the human body's key processes, leading, ultimately, to death. There are many challenges associated with treating this disease, but they generally stem from the difficulty in differentiating the disease from the host and the ability of even a few cells to survive, recover and return. The most common treatments generally combine surgery with some type of chemotherapy or radiotherapy. Chemotherapy utilises chemicals that kill fast-growing cells and thereby disproportionally affect the rapidly multiplying cancer cells. Radiotherapy targets the tumour with radiation to cause damage and cell death. Both have their advantages and disadvantages, and both are often not 100 per cent effective. To improve these treatments, it is necessary to understand more about their precise effects on cells and, particularly, what defences cells have against their effects. Senior Principal Researcher Dr Masao Suzuki of the National Institutes for Quantum and Radiological Science and Technology (QST) is utilising the considerable radiological resources of QST to investigate the effects of different types of radiation on cells under different conditions.

Temporal characterisation of silicon sensors on Timepix3 ASICs

The timing performance of silicon sensors bump-bonded to Timepix3 ASICs is investigated, prior to and after different types of irradiation up to 8 × 1015 1 MeV neq cm−2. The sensors have been tested with a beam of charged particles in two different configurations, perpendicular to and almost parallel to the incident beam. The second approach, known as the grazing angles method, is shown to be a powerful method to investigate not only the charge collection, but also the time-to-threshold properties as a function of the depth at which the charges are liberated.

Irradiation behavior and recovery effect of ferroelectric properties of PZT thin films* *Project supported by the National Natural Science Foundation of China (Grant No. 51802056), the Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, and the Key Laboratory of Micro-systems and Micro-structures Manufacturing (Harbin Institute of Technology), Ministry of Education, China.

Lead zirconate titanate piezoelectric ceramics have important applications in space and aerospace technology, but the effect and physical mechanism of charged particle radiation on their performance yet to be clarified. In this study, we characterized PbZr0.52Ti0.48O3 (PZT) thin films, and changes in the ferroelectric properties of the films before and after electron and proton irradiation were investigated. The natural and heat treatment recoverability of the ferroelectric properties were studied, and the damages and mechanisms of different types of radiation in PZT films were also investigated. The results show that, in addition to ionization damages, electron irradiation causes certain structural damage on the PZT film, and the large structural damage caused by proton irradiation reduces drastically the ferroelectricity of the PZT film.