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Gallic acid (GA) is a powerful antioxidant extracted from plants of the Brazilian Cerrado. Oxidative stress plays an important role in the occurrence of radiation-induced osteonecrosis in patients treated for head and neck cancer. There is a need to develop research aimed at developing complementary therapies to prevent or reverse bone damage. The aim of the present study was to investigate the effect of GA in preosteoblasts exposed to therapeutic ionizing radiation. MC3T3-E1 preosteoblast cells were treated with 10 µM GA and exposed to 6 Gy ionizing radiation. We performed in vitro assays of cell proliferation, oxidative stress analysis by detection of reactive oxygen species, and alkaline phosphatase assay. GA at lower concentrations was able to significantly increase proliferation and inhibit radiation-induced generation of reactive oxygen species in osteoblast precursor cells, despite ionizing radiation-induced injury. Furthermore, GA significantly increased alkaline phosphatase at a dose of 6 Gy. The findings suggested that GA could attenuate ionizing radiation-induced injuries in osteoblast precursor cells. Moreover, in vivo studies are needed to better investigate the role of GA in osteonecrosis, especially in cancer patients undergoing radiotherapy or taking antiresorptive drugs.

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Exposure to ionizing radiation (IR) is inevitable in various X-ray imaging examinations, with computed tomography (CT) being a major contributor to increased human radiation exposure. Ionizing radiation may cause structural damage to macromolecules, particularly DNA, mostly through an indirect pathway in diagnostic imaging. The indirect pathway primarily involves the generation of reactive oxygen species (ROS) due to water radiolysis induced by IR, leading to DNA damage, including double-strand breaks (DSB), which are highly cytotoxic. Antioxidants, substances that prevent oxidative damage, are proposed as potential radioprotective agents. This Study Protocol article presents the rationale for selecting vitamin C as a preventive measure against CT-associated IR-induced DNA damage, to be investigated in a randomized placebo-controlled trial, with a full in vivo design, using an oral easy-to-use schedule administration in the outpatient setting, for the single CT examination with the highest total global IR dose burden (contrast-enhanced abdomen and pelvis CT). The study also aims to explore the mediating role of oxidative stress, and it has been written in adherence to the Standard Protocol Items recommendations.

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Home office (HO) stands out as one of the most promising and popular forms of teleworking, especially after the COVID-19 pandemic. Therefore, many companies want to implement or maintain this working method, given its numerous advantages. However, there are adverse effects that are mainly related to physical and mental health. This article presents ergonomic analyses of HOs in neighborhoods considered heat islands. Temperature levels, extreme low-frequency non-ionizing radiation (ELF-NIR), illuminance, physical layout characteristics, and physiological parameters of teleworkers were measured. The results reveal that 92% of these professionals work 6 to 8 h daily with an ambient temperature between 25 and 30 °C, illumination levels in the range 11.20-290 Lux, and ELF-NIR > 0.4 µT. The majority of teleworkers are overweight (BMI > 24.9), and some of them have blood pressure higher than average values (129 mmHg for systolic and 84 mmHg for diastolic) in addition to a reduction in the number of red blood cells and hematocrits. Symptoms such as burning sensation, dryness, tired eyes, redness, itching, and photophobia (light sensitivity) show a 68.95% similarity. These HOs do not meet the required ergonomic and health standards.

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INTRODUCTION: The global incidence of thyroid cancer (TC) has increased in the last decades. While improvements in diagnosis may contribute, overdiagnosis is also a possibility. This review focuses on the epidemiology, risk factors, and immune microenvironment associated with differentiated TC (DTC). AREAS COVERED: A search was conducted in Scielo, Scopus, and EMBASE databases, involving 72 articles. TC is the most common endocrine neoplasm, with DTC form being predominant. Its incidence has globally risen, particularly among women aged over 45. Endogenous risk factors for DTC include genetic disorders, race, age, female gender, obesity, and type 2 diabetes mellitus. Environmental risks involve ionizing radiation, whether through therapeutic treatment or environmental contamination from nuclear accidents, iodine deficiency, endocrine disruptors, residence in volcanic areas, environmental pollution, and stress. The use of anti-obesity medications remains controversial. The tumor's immune microenvironment is the histological space where tumor cells interact with host cells, crucial for understanding aggressiveness. Immunotherapy emerges as a promising intervention. EXPERT OPINION: Recent advances in DTC management offer transformative potential, requiring collaborative efforts for implementation. Emerging areas like precision medicine, molecular profiling, and immunotherapy present exciting prospects for future exploration, shaping the next era of diagnostic and therapeutic strategies in thyroid cancer research.

The global incidence of thyroid cancer (TC) has significantly increased, attributed partly to improved diagnosis and potentially to overdiagnosis. This review focuses on the epidemiology, risk factors, and immune microenvironment associated with differentiated TC (DTC). DTC is the most common endocrine neoplasm, and predominantly affects women over 45 years old. Endogenous risk factors include genetic disorders, race, age, female gender, obesity, and type 2 diabetes mellitus (T2DM). Environmental risks encompass ionizing radiation, iodine deficiency, endocrine disruptors, volcanic residence, pollution, and stress. The use of glucagon-like peptide 1 agonists remains controversial. The tumor's immune microenvironment is crucial for understanding aggressiveness, with immunotherapy showing promise. Understanding both macro and microenvironmental factors is crucial for devising effective prevention and treatment strategies for DTC.

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Radiotherapy is a key treatment option for a wide variety of human tumors, employed either alone or alongside with other therapeutic interventions. Radiotherapy uses high-energy particles to destroy tumor cells, blocking their ability to divide and proliferate. The effectiveness of radiotherapy is due to genetic and epigenetic factors that determine how tumor cells respond to ionizing radiation. These factors contribute to the establishment of resistance to radiotherapy, which increases the risk of poor clinical prognosis of patients. Although the mechanisms by which tumor cells induce radioresistance are unclear, evidence points out several contributing factors including the overexpression of DNA repair systems, increased levels of reactive oxygen species, alterations in the tumor microenvironment, and enrichment of cancer stem cell populations. In this context, dysregulation of microRNAs or miRNAs, critical regulators of gene expression, may influence how tumors respond to radiation. There is increasing evidence that miRNAs may act as sensitizers or enhancers of radioresistance, regulating key processes such as the DNA damage response and the cell death signaling pathway. Furthermore, expression and activity of miRNAs have shown informative value in overcoming radiotherapy and long-term radiotoxicity, revealing their potential as biomarkers. In this review, we will discuss the molecular mechanisms associated with the response to radiotherapy and highlight the central role of miRNAs in regulating the molecular mechanisms responsible for cellular radioresistance. We will also review radio-miRs, radiotherapy-related miRNAs, either as sensitizers or enhancers of radioresistance that hold promise as biomarkers or pharmacological targets to sensitize radioresistant cells.

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The danger of ionizing radiation exposure to human health is a concern. Since its wide use in medicine and industry, the development of radioprotectors has been very significant. Adenosine exerts anti-inflammatory actions and promotes tissue protection and repair, by activating the P1 receptors (A1, A2A, A2B, and A3). Zebrafish (Danio rerio) is an appropriate tool in the fields of toxicology and pharmacology, including the evaluation of radiobiological outcomes and in the search for radioprotector agents. This study aims to evaluate the effect of adenosine in the toxicity induced by radiation in zebrafish. Embryos were treated with 1, 10, or 100 µM adenosine, 30 min before the exposure to 15 Gy of gamma radiation. Adenosine potentiated the effects of radiation in heart rate, body length, and pericardial edema. We evaluated oxidative stress, tissue remodeling and inflammatory. It was seen that 100 µM adenosine reversed the inflammation induced by radiation, and that A2A2 and A2B receptors are involved in these anti-inflammatory effects. Our results indicate that P1R activation could be a promising pharmacological strategy for radioprotection.

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Radiotherapy (RT) is a common treatment for head and neck tumors. However, it causes several physical and behavioral side effects, and no study has assessed the emotional effects in rats. Therefore, the present study evaluated the influence of head and neck RT on the behavior and body weight gain in Wistar rats. Fifty-four male Wistar rats were allocated into six groups (n = 9) according to the irradiation dose, which was applied at the first day of the experiment: RT-7.5 (single dose of 7.5 Gy); RT-10 (single dose of 10 Gy); RT-15 (single dose of 15 Gy); RT-30 (single dose of 30 Gy); Control (without RT). The animals were irradiated in the region of the right face, and behavioral tests and weighing were performed on days one, seven, and 28. The open field and Y-maze tests were undertaken to analyze the animal's behavior. The dose of 30 Gy was lethal when applied to the head and neck region. The irradiated animals had less weight gain when compared to the control ones, but there was no statistical difference. In the open field and Y-maze tests, lower mobility of animals in the RT groups was observed both on day seven and at the end of the experiment (day 28) when compared to the control rats (p < 0.05). It was possible to conclude that the different doses of radiation induced depressive behavior in the animals, and that the weight gain tended to be lower in the irradiated groups, however, without statistical difference.

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ABSTRACT Objective: To compare cancer mortality among workers exposed to gamma and X radiation and the general population of the city of São Paulo, as well as that of the subgroup monitored with those not monitored for gamma and X radiation in a work unit with ionizing radiation based in the city of São Paulo. Methods: Between 2016 and 2021, a retrospective open cohort study was carried out with workers who were employed from 08/31/1956 to 12/31/2016 based on data collected at the company and in official institutions. Standardized mortality ratios (SMR) were calculated by sex, age and calendar period of cancers grouped according to type, risk factor and organ system in two analyses: in the external analysis, the mortality of the study population was compared with that of the general population of the city of São Paulo; In the internal analysis, the mortality of the monitored subgroup was compared with that of the subgroup not monitored for gamma and X radiation. Results: The external mortality analysis showed SMR=0.224 (95%CI 0.208-0.240) and the healthy worker effect, while the internal mortality analysis showed SMR=0.685 (95%CI 0.618-0.758). Conclusion: This study showed lower cancer mortality among exposed workers when compared to mortality in the general population and the healthy worker effect. Among workers monitored for gamma and X radiation, cancer mortality was lower when compared to those not monitored.

RESUMO Objetivo: Comparar a mortalidade por câncer entre trabalhadores expostos à radiação gama e X e a população geral do município de São Paulo, bem como a do subgrupo monitorado com o não monitorado para radiação gama e X em uma unidade de trabalho sediada no município de São Paulo. Métodos: Entre 2016 e 2021 foi realizado estudo de coorte aberta retrospectiva com trabalhadores que tiveram vínculo empregatício desde 31/08/1956 até 31/12/2016 a partir de dados coletados na empresa e em instituições oficiais. Foram calculadas as razões de mortalidade padronizadas (RMP) por sexo, idade e período calendário de cânceres agrupados segundo o tipo, o fator de risco e o sistema orgânico em duas análises: na análise externa, comparou-se a mortalidade da população de estudo com a da população geral do município de São Paulo; já na análise interna, comparou-se a mortalidade do subgrupo monitorado com a do subgrupo não monitorado para radiação gama e X. Resultados: A análise externa de mortalidade mostrou RMP=0,224 (IC95% 0,208-0,240) e o efeito do trabalhador sadio, enquanto a análise interna de mortalidade mostrou RMP = 0,685 (IC95% 0,618-0,758). Conclusão: Este estudo mostrou menor mortalidade por câncer entre os trabalhadores expostos quando comparada com a mortalidade da população geral e o efeito do trabalhador sadio. Entre os trabalhadores monitorados para radiação gama e X, a mortalidade por câncer foi menor quando comparada com a dos não monitorados.

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Introducción: El uso de radiografías como elemento complementario para el diagnóstico es fundamental para la práctica profesional de todo cirujano dentista. Por tanto, es importante conocer no solo los beneficios de la radiología oral y los fundamentos de protección radiológica, sino también determinar su nivel de aplicación o la adherencia frente al cumplimiento de los aspectos normativos que regulan el uso de la radiación ionizante en odontología. Objetivo: Relacionar el conocimiento sobre los cuidados en radiología bucal, las ventajas y los peligros en la toma de radiografías con el cumplimiento de las normas de protección radiológica y radiación ionizante en estudiantes de odontología de una clínica dental docente. Métodos: La población de estudio estuvo constituida por 180 estudiantes del cuarto año de la carrera de odontología, que emplearon los equipos radiológicos en la clínica docente asistencial durante los años 2019 (segundo semestre) y 2020 (primer trimestre). Se tomó como muestra representativa a 104 estudiantes, incorporados al estudio mediante muestreo aleatorio simple. Se aplicaron dos instrumentos de recolección de datos, uno para evaluar el conocimiento (cuestionario) y otro para verificar el cumplimiento de normas (lista de chequeo) sobre la protección radiológica y el diagnóstico por imágenes en la práctica odontológica. Para el análisis estadístico se aplicó la prueba estadística chi cuadrado con un nivel de significancia del 95 %. Resultados: No se encontró relación estadísticamente significativa (p = 0,30) entre el conocimiento teórico sobre la protección radiológica y el diagnóstico por imágenes, respecto el cumplimiento de las normas que regulan su aplicación (p > 0,05). El 90 % de participantes tienen conocimientos entre regulares y excelentes. Sin embargo, solo el 32 % cumple las normas técnicas de protección sobre radiación ionizante en su práctica clínica. Conclusión: Los estudiantes de odontología tienen suficiente conocimiento sobre protección radiológica y diagnóstico por imágenes. Sin embargo, este conocimiento no se refleja en prácticas adheridas a las normas.

Introduction: The use of radiographs as a complementary element for diagnosis is fundamental to the professional practice of every dental surgeon. Therefore, it is important to know not only the benefits of oral radiology and the fundamentals of radiological protection, but also to determine their level of application or adherence to compliance with the regulatory aspects that regulate the use of ionizing radiation in dentistry. Objective: To relate the knowledge of oral radiology care, the advantages and dangers in taking radiographs with compliance with the norms of radiological protection and ionizing radiation in dental students of a dental teaching clinic. Methods: The study population consisted of 180 fourth year dental students who used the radiological equipment in the teaching dental clinic during 2019 (second semester) and 2020 (first quarter). A representative sample of 104 students was taken, incorporated into the study by simple random sampling. Two data collection instruments were applied, one to evaluate knowledge (questionnaire) and the other to verify compliance with standards (checklist) on radiological protection and diagnostic imaging in dental practice. For the statistical analysis the chi-square statistical test was applied with a significance level of 95 %. Results: No statistically significant relationship was found (p = 0.30) between theoretical knowledge of radiological protection and diagnostic imaging with respect to compliance with the norms that regulate its application (p > 0.05). Ninety percent of participants have fair to excellent knowledge. However, only 32 % comply with the technical norms of ionizing radiation protection in their clinical practice. Conclusion: Dental students have sufficient knowledge of radiation protection and diagnostic imaging. However, this knowledge is not reflected in practices that adhere to the standards.

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The radiological protection has the purpose of safeguarding the physical well-being of the user, preventing exposure to detrimental levels of ionizing radiation. This study introduces a novel, cost-effective category of lead-free elastomeric material designed for radiation shielding. The filler compounds utilized are notably lighter than conventional lead-based materials, enhancing user ergonomics during application. They comprise of a blend of barium sulfate combined or not with magnesium oxide with addition-cure liquid silicone rubber. To ensure the effectiveness of the radiation shielding, X-ray transmission measurements were performed for the different thicknesses of the materials and the results compared with Monte Carlo simulations. Additionally, the physical properties of the new materials, such as density, homogeneity, tensile strength, viscosity, and wettability, were also evaluated. The findings indicate that both materials fulfill the requirement for application in radiation protection garments.

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Significance: Radiotherapy, which employs ionizing radiation to destroy or prevent the multiplication of tumor cells, has been increasingly used in the treatment of neoplastic diseases, especially cancers. However, radiation collaterally leads to prolonged periods of sperm count suppression, presumably due to impaired spermatogenesis by depleting the germ cell pool, which has long-term side effects for male reproduction. Recent Advances: Studies of antioxidant compounds as a potential strategy for male fertility preservation have been performed mainly from animal models, aiming to prevent and restore the male germinal tissue and its function, particularly against the oxidative stress effects of radiation. Evidence in preclinical and clinical trials has shown that inhibitors of the renin-angiotensin system and other drugs, such as statins and metformin, are candidates for ameliorating radiation-induced damage to several tissues, including the testis and prostate. Critical Issues: Research for developing an ideal radioprotective agent is challenging due to toxicity in the normal tissue, tumor radioresistance, cellular response to radiation, costs, regulation, and timeline development. Moreover, male radioprotection experiments in humans, mainly clinical trials, are scarce and use few individuals. This scenario is reflected in the slow progress of innovation in the radioprotection field. Future Directions: Expanding human studies to provide clues on the efficacy and safety of radioprotective compounds in the human reproductive system is necessary. Drug repurposing, frequently used in clinical practice, can be a way to shorten the development pipeline for innovative approaches for radioprotection or radiomitigation of the repercussions of radiotherapy in the male reproductive system.

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Resistance to radio and chemotherapy in Glioblastoma (GBM) is correlated with its malignancy, invasiveness, and aggressiveness. The Rho GTPase pathway plays important roles in these processes, but its involvement in the GBM response to genotoxic treatments remains unsolved. Inhibition of this signaling pathway has emerged as a promising approach for the treatment of CNS injuries and diseases, proving to be a strong candidate for therapeutic approaches. To this end, Rho-associated kinases (ROCK), classic downstream effectors of small Rho GTPases, were targeted for pharmacological inhibition using Y-27632 in GBM cells, expressing the wild-type or mutated p53 gene, and exposed to genotoxic stress by gamma ionizing radiation (IR) or cisplatin (PT). The use of the ROCK inhibitor (ROCKi) had opposite effects in these cells: in cells expressing wild-type p53, ROCKi reduced survival and DNA repair capacity (reduction of γH2AX foci and accumulation of strand breaks) after stress promoted by IR or PT; in cells expressing the mutant p53 protein, both treatments promoted longer survival and more efficient DNA repair, responses further enhanced by ROCKi. The target DNA repair mechanisms of ROCK inhibition were, respectively, an attenuation of NHEJ and NER pathways in wild-type p53 cells, and a stimulation of HR and NER pathways in mutant p53 cells. These effects were accompanied by the formation of reactive oxygen species (ROS) induced by genotoxic stress only in mutant p53 cells but potentiated by ROCKi and reversed by p53 knockdown. N-acetyl-L-cysteine (NAC) treatment or Rac1 knockdown completely eliminated ROCKi's p53-dependent actions, since ROCK inhibition specifically elevated Rac-GTP levels only in mutant p53 cells. Combining IR or PT and ROCKi treatments broadens our understanding of the sensitivity and resistance of, respectively, GBM expressing wild-type or mutant p53 to genotoxic agents. Our proposal may be a determining factor in improving the efficiency and assertiveness of CNS antitumor therapies based on ROCK inhibitors. SIGNIFICANCE: The use of ROCK inhibitors in association with radio or chemotherapy modulates GBM resistance and sensitivity depending on the p53 activity, suggesting the potential value of this protein as therapeutic target for tumor pre-sensitization strategies.

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OBJECTIVE: This study aimed to evaluate the dose-response effects of ionizing radiation (IR) on alveolar bone repair and bone strength after tooth extraction. MATERIALS AND METHODS: A total of 32 male Wistar rats were used in the study, 28 animals were included in the final analysis, and n = 7 for each experimental group. Mandibular first molars were extracted. After 7 days, the animals were randomly divided into four groups according to single-dose irradiation: NIr, control group; Ir15, irradiated at 15 Gy; Ir20, irradiated at 20 Gy; and Ir30, irradiated at 30 Gy. The tooth extraction sites were subjected to micro-computed tomography (micro-CT), histological, histomorphometric, and biomechanical analyses 14 days after extraction. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test (α = 0.05). RESULTS: Micro-CT analysis revealed that IR led to lower values of bone volume (BV, in mm3) (0.68 ± 0.08, P < 0.001) and bone volume fraction, ratio of the segmented bone volume to the total volume of the region of interest (BV/TV, in %) (44.1 ± 8.3, P < 0.001) for the Ir30 group compared to the control group. A significantly lower amount of newly formed bone was observed in the Ir30 (P = 0.005) than in the Ir15 group. The histomorphometric results of quantification of bone matrix neoformation and the micro-CT were in agreement, demonstrating greater damage to the Ir30 group. IR30 cells showed a lower percentage of densely packed collagen than control cells. No significant differences were found in the biomechanical parameters. CONCLUSION: IR affects alveolar bone repair. A dose of 30 Gy reduced the bone healing process owing to a smaller amount of newly formed bone and a lower percentage of densely packed collagen. Therefore, a dose of 30 Gy can be used to successfully establish an animal model of an irradiated mandible that mimics the irradiated clinical conditions. CLINICAL RELEVANCE: Radiotherapy can lead to severe side effects and tooth extraction is a major risk factor. A proper understanding of the pathological mechanisms of radiation in alveolar bone repair requires the establishment of a suitable animal model of clinical conditions.

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BACKGROUND: This pilot study aimed to evaluate the mutagenic effects in cells of the oral mucosa after exposure to two different cone beam computed tomography (CBCT). METHODS: Eighteen adults were submitted to the different CBCT (Carestream CS8100 3D and I-CAT). The cells were collected immediately before the CBCT exposure and 10 days later, when the material was placed on a slide and stained using the Feulgen/Fast Green technique. Microscopic analysis counted micronuclei and other nuclear alterations, which are indicative of cytotoxicity such as pyknosis, karyolysis, karyorrhexis, and binucletion. 2000 cells were analyzed. The statistical analysis was performed with the Wilcoxon Signed-Rank test to compare the frequency of cellular alterations, and the Mann-Whitney U test to compare different CBCTs, both with a significance level of 5%. RESULTS: There was no statistically significant difference in the micronucleated cell count before and after the exposition to the ionizing radiation from I-CAT (p = .298) and CS8100 3D (p = .203) A significate increase of pyknosis (p < .001), karyolysis (p < .001), karyorrhexis (p < .001), and binucletion (p < .001) were noted on I-CAT CBCT. There was no statistically significant difference in cellular alterations in CS8100 3D CBCT. CONCLUSION: Despite the increase in micronuclei after exposure, this study indicates that there is no evidence of genotoxicity. On the other hand, the I-CAT CBCT produced cytotoxic effects.

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It is crucial to monitor the levels of Non-Ionizing Radiation (NIR) to which the general population may be exposed and compare them to the limits defined in the current standards, in view of the rapid rise of communication services and the prospects of a connected society. A high number of people visits shopping malls and since these locations usually have several indoor antennas close to the public, it is therefore a kind of place that must be evaluated. Thus, this work presents measurements of the electric field in a shopping mall located in Natal, Brazil. We proposed a set of six measurement points, following two criteria: places with great the flow of people and the presence of one or more Distributed Antenna System (DAS), co-sited or not with WiFi access points. Results are presented and discussed in terms of the distance to DAS (conditions: near and far) and flow density of people in the mall (scenarios: low and high number of people). The highest peaks of electric field measured were 1.96 and 3.26 V/m, respectively corresponding to 5% and 8% of the limits defined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Brazilian National Telecommunication Agency (ANATEL).

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Radiotherapy causes destruction of tumor cells, but also threatens the integrity and survival of surrounding normal cells. Then, woman submitted to irradiation for cancer treatment may present permanent ovary damage, resulting in impaired fertility. The objective of this study was to investigate the effects of therapeutic doses of ionizing radiation (IR), used for ovarian cancer treatment in humans, on bovine cumulus-oocyte complexes (COCs) as experimental model. Bovine ovaries were exposed to 0.9 Gy, 1.8 Gy, 3.6 Gy or 18.6 Gy IR, and then COCs were collected and used to evaluate: (a) oocyte nuclear maturation; (b) presence of phosphorylated H2A.X (γH2AX), as an indicator of DNA double-strand breaks (DSBs); and (c) expression of genes involved in DNA repair (TP53BP1, RAD52, ATM, XRCC6 and XRCC5) and apoptosis (BAX). The radiation doses tested in this study had no detrimental effects on nuclear maturation and did not increase γH2AX in the oocytes. However, IR treatment altered the mRNA abundance of RAD52 (RAD52 homolog, DNA repair protein) and BAX (BCL2-associated X protein). We conclude that although IR doses had no apparent effect on oocyte nuclear maturation and DNA damage, molecular pathways involved in DNA repair and apoptosis were affected by IR exposure in cumulus cells.

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Ionizing radiation has been used for decades and expanded to several applications in multivariate sectors, becoming an important tool to promote controlled chemical reactions in polymeric structures, according to their chemical properties for developing new materials. In addition, the use of radiation can also be applied in order to reduce or eliminate compounds from solutions that may be harmful or of low interest. In this review, we overviewed the chemistry behind material irradiation and the attractive use of ionizing radiation in scientific and industrial development. In this regard, the review was divided into three main sections titled (1) chemical kinetics intermediated by radiation, (2) chemical bonds intermediated by radiation, and (3) radiation chemistry on polymers. We concluded that graft polymerization, crosslinking and chain scission reactions induced by ionizing radiation are very efficient and green strategies for developing new materials with improved properties. Furthermore, water radiolysis plays a key role in the degradation of several contaminants, including pharmaceuticals and microplastics, in aqueous solutions. However, more studies must be conducted to complement the existing theory about the proposed mechanisms responsible for modifying the chemical, mechanical, thermal, optical, and so forth properties of irradiated materials.

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OBJECTIVE: To describe and analyze the exposure to ionizing radiation of orthopedic residents. METHOD: A prospective study was carried out to evaluate the degree of exposure to ionizing radiation with a bandage dosimeter placed under the lead apron for medical residents for 10 months. An online survey measured the degree of knowledge about radiation safety. RESULTS: 54 resident physicians participated. 55.6% report having knowledge of the existence of radiological protection equipment and 40.7% report that they had previous training in its use. 77.8% use the leaded apron and 31.5% use thyroid protection. 81.5% were positioned less than 1 meter from the source of the X-ray production of the arc in C. The total mean radiation exposure was 2.9 ± 2.17 mSv (95% confidence interval: 1.25-14.28; p = 0.424). CONCLUSIONS: Orthopedic residents present radiation doses below the International Commission on Radiological Protection recommended limit. However, there is a lack of knowledge of radiation protection and as well as a lack of interest and ignorance of the adverse effects of radiation.

OBJETIVO: Describir y analizar la exposición a radiación ionizante de los residentes de ortopedia. MÉTODO: Se realizó un estudio prospectivo para evaluar el grado de exposición a radiación ionizante con un dosímetro de placa colocado debajo del mandil plomado a médicos residentes, por 10 meses. Mediante una encuesta en línea se midió el grado de conocimientos sobre seguridad radiológica. RESULTADOS: Participaron 54 médicos residentes. El 55.6% refiere tener conocimiento de la existencia de equipo de protección radiológica y el 40.7% refiere que tuvo entrenamiento previo en su uso. El 77.8% utiliza el mandil plomado y el 31.5% la protección tiroidea. El 81.5% se posicionó a menos de 1 metro de la fuente de producción de rayos X del arco en C. La exposición a la radiación media total fue de 2.9 ± 2.17 mSv (intervalo de confianza del 95%: 1.25-14.28; p = 0.424). CONCLUSIONES: Los médicos residentes de ortopedia presentan dosis de radiación menores que el límite recomendado por la International Commission on Radiological Protection. Sin embargo, existe una falta de conocimientos sobre protección radiológica, así como falta de interés e ignorancia de los efectos adversos de la radiación.

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Pacientes que passam pela radioterapia (RT) no tratamento de tumores malignos de cabeça e pescoço podem ter efeitos adversos na cavidade bucal, especialmente nos dentes levando à instalação de cárie que pode atingir a cavidade pulpar evoluindo para necrose e desenvolvimentoda periodontite apical (PA). Até o presente momento não se conhece a evolução da PA, bem como a microbiota endodôntica intracanal após procedimentos de RT. Assim, este estudo propôs avaliar a PA induzida em ratos submetidos à RT analisando o volume e área da PA e o processo inflamatório periapical (parte1) e monitorando o perfil microbiano intracanal (parte 2). Parte 1: foram utilizados 40 ratos machos Wistar distribuídos em 4 grupos (n=10): PA: com indução da PA; RTPA: aplicação da RT e indução da PA; RT: aplicação da RT; Controle: sem qualquer intervenção. Parte 2: foram utilizados 20 ratos machos Wistar distribuídos em 2 grupos(n=10): PA-TE: indução da PA e tratamento endodôntico (TE); RT-PA-TE: aplicação da RT, indução da PA e TE. Nos grupos RT, os animais foram submetidos a RT no dia 1 do experimento, com a dosagem de 15 Gy localizada no lado direito da face. A PA foi induzida no dia 7 através da exposição das cavidades pulpares dos primeiros molares ao meio oral por um período de 21 dias. Após 21 dias da indução da PA nos grupos de TE os canais foram preparados até a lima K# 30 associada à solução de hipoclorito de sódio 1%. Foram feitas coletas do canal radicular após abertura coronária (S1) e após preparo dos canais (S2), para avaliar o perfil microbiano intracanal. Os animais foram eutanasiados no dia 28 do experimento. Nos animais da Parte 1: foram realizadas análises comportamentais no início do experimento e no dia da eutanásia. Amostras foram submetidas às análises: radiográfica, microtomográfica e histológica e da expresão gência de mediadores ósseos RANKL, OPG, TRAP. Parte 2: o conteúdo coletado dos canais foi avaliado por cultura (UFC/mL) utilizando meios seletivos para microorganismos anaeróbios facultativos e/ou aeróbios; anaeróbios; leveduras; espécies de enterococos; streptococos; Enterobactérias e estafilococos. Os resultados mostraram que o ganho de peso foi significante menor nos animais submetidos a RT sendo o grupo PA-RT com menor ganho de peso. Verificou-se diminuição na movimentação média dos animais nos grupos com RT. No grupo RTPA: A área e o volume da lesão periapical foi significantemente maior nas análises microtomográficas e radiográficas; Houve maior intensidade de extensão e intensidadedo infiltrado inflamatório. A expressão gênica de de OPG e TRAP foi alterada, influenciando no desenvolvimento da PA. A carga bacteriana foi principalmente composta por microrganismos anaeróbios facultativos, aeróbios, estreptococos e anaeróbios. O preparo biomecânico foi eficienciente na redução do número de espécies bacterianas (AU).

Patients who undergo radiotherapy (RT) in the treatment of malignant head and neck tumors may have adverse effects on the oral cavity, especially on the teeth, leading to the installation of caries that can reach the pulp cavity, progressing to necrosis and development of apical periodontitis (AP). Until the present moment, the evolution of AP is not known, as well as the intracanal endodontic microbiota after RT procedures. Thus, this study proposed to evaluate the BP induced in rats submittedto RT by analyzing the volume and area of the PA and the periapical inflammatory process (part 1) and monitoring the intracanal microbial profile (part 2). Part 1: 40 male Wistar rats were used, divided into 4 groups (n=10): PA: with PA induction; RT- PA: RT application and BP induction; RT: RT application; Control: without any intervention. Part 2: 20 male Wistar rats distributed in 2 groups (n=10) were used: PA-TE: PA induction and endodontic treatment (ET); RT-PA-TE: application of RT, induction of PA and TE. In the RT groups, the animals were submitted to RT on day1 of the experiment, with the 15 Gy dose located on the right side of the face. PA wasinduced on day 7 by exposingthe pulp cavities of the first molars to the oral medium for a period of 21 days. After 21days of BP induction in the TE groups, the canals were prepared with a K# 30 file associated with a 1% sodium hypochlorite solution. Root canal samples were taken after coronal opening (S1) and after root canal preparation (S2), to evaluate the intracanal microbial profile. The animals were euthanized on day 28 of the experiment.In animals from Part 1: behavioral analyzes were performed at the beginning of the experiment and on the day of euthanasia. Samples were submitted to radiographic, microtomographic and histological analyses, and the expression of bone mediators RANKL, OPG, TRAP. Part 2: the content collected from the canals was evaluated by culture (CFU/mL) using selective media for facultative anaerobic and/or aerobic microorganisms; anaerobes; yeasts; species of enterococci; streptococci; Enterobacteriaceae and staphylococci. The results showed that the weight gain was significantly lower in the animals submittedto RT, with the PA-RT group having the lowest weight gain. There was a decrease in the average movement of the animals in the groups with RT. In the RT-PA group:The area and volume of the periapical lesion was significantly greater in the microtomographic and radiographic analyses; There was a greater intensity of extension and intensity of the inflammatory infiltrate. The geneexpression of OPG and TRAP was altered, influencing the development of AP. The bacterial load was mainly composed of facultative anaerobic, aerobic, streptococcal and anaerobic microorganisms. The biomechanical preparation was efficient in reducing the numberof bacterial species (AU)

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RESUMO

Objective: The aim of the present study is to evaluate whether a "radiation free" method using 3D facial scan can replace Cone Beam Computed Tomography (CBCT) volumetric rendering of soft tissue of the patient to assess maxillofacial surgery outcomes and compare the reference points and angular measurements of patient facial soft tissue. Material and Methods: Facial soft tissue scan of the patient's face, before and after orthognathic surgery and a CBCT of the skull for volumetric rendering of soft tissues were carried out. The 3D acquisitions were processed using Planmeca ProMax 3D ProFace® software (Planmeca USA, Inc.; Roselle, Illinois, USA). The participant were positioned in a natural position during the skull scannering. Three sagittal angular measurements were performed (Tr-NA, Tr-N-Pg, Ss-N-Pg) and two verticals (Go-N-Me, Tr-Or-Pg) on facial soft tissue scan and on the patient's 3D soft tissue CBCT volumetric rendering. Results: A certain correspondence has been demonstrated between the measurements obtained on the Proface and those on the CBCT. Conclusion: A radiation free method was to be considered an important diagnostic tool that works in conditions of not subjecting the patient to harmful ionizing radiation and it was therefore particularly suitable for growing subjects. The soft tissue analysis based on the realistic facial scan has shown sufficient reliability and reproducibility even if further studies are needed to confirm the research result.(AU)

Objetivo:Avaliar se um método "livre de radiação" usando escaneamento facial 3D pode substituir a renderização volumétrica da tomografia computadorizada de feixe cônico (TCFC) dos tecidos moles do paciente para analisar os resultados da cirurgia maxilofacial e comparar os pontos de referência e medições angulares afim de avaliar a correspondência entre as duas metodologias. Material e Métodos: Foi realizado o escaneamento dos tecidos moles faciais do paciente, antes e depois da cirurgia ortognática e uma tomografia computadorizada de feixe cônico do crânio para renderização volumétrica dos tecidos moles. As aquisições 3D foram processadas usando o software Planmeca ProMax 3D ProFace® (Planmeca USA, Inc.; Roselle, Illinois, USA). O participante foi posicionado em posição natural durante o escaneamento do crânio. Três medições angulares sagitais foram realizadas (Tr-NA, Tr-N-Pg, Ss-N-Pg) e duas verticais (Go-N-Me, Tr-Or-Pg) nas imagens de scaneamento e nas imagens do tecido mole facial da reconstrução tridimensional da TCFC. Resultados: Uma certa correspondência foi demonstrada entre as medidas obtidas no Proface® e aquelas na TCFC. Conclusão: Um método livre de radiação deve ser considerado uma importante ferramenta de diagnóstico que funciona em condições de não submeter o paciente a radiação ionizante nociva e, portanto, é particularmente adequado para indivíduos em crescimento. A análise de tecidos moles com base na varredura facial realista mostrou confiabilidade e reprodutibilidade, porém mais estudos são necessários para confirmar o resultado da pesquisa. (AU)

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