Radiation Exposure Conditions Research Articles

Radioprotective ingredients of a composite dairy product

Food products that have an anti-radiation effect and can be used in conditions of increased radiation are of particular interest. Scientifically based rationing of such products in the daily diet will make it possible to effectively use them to adapt the body to increased radiation and eliminate the effects of radiation exposure during treatment or examination. The purpose of the research presented in the paper is to analyze the nutritional and physiological causes of chronic nutrient deficiency of radioprotective microelements in the diet, to study the qualitative and biological characteristics of radioprotective ingredients to create a milk-based anti-radiation composition. The experimental part of the study has related to researching the mineral composition of selected ingredients and their antioxidant activity. The data obtained indicate that milk thistle flour contains a large amount of calcium, and sunflower meal contains potassium. In terms of potassium content, sunflower meal exceeds the microelement content in milk thistle by 50 %. The amount of calcium in milk thistle is 67 % higher compared to sunflower meal. In addition, plant raw materials are a source of magnesium, iron, zinc, copper, phosphorus and have pronounced antioxidant activity. As a result a scientific substantiation of the addition of ingredients for the production of radioprotective fermented milk product and its use in therapeutic and prophylactic nutrition for adults has been carried out in order to prevent radiation complications and remove radionuclides from the body. The normalized amount of ingredients for consumption per day has been calculated according to recommended diets, nutritional, physiological value, and physiological activity. Standards have been established for enriching micronutrients in the production of a radioprotective dairy product designed to increase the body's resistance to the action of free radical processes and enhance antioxidant capacity under conditions of radiation exposure.

Clinical guidelines for prevention, diagnostics, treatment and recovery from acute radiation injuries: classification and basic pathology

The provision of state guarantees to citizens with medical care is achieved by compliance with clinical recommendations by medical organizations. However, acute diseases (conditions) caused by excess radiation were excluded from the relevant pathologies for the development of appropriate clinical recommendations. The current events increase the relevance of acute radiation pathology for the healthcare system and determine the high risk of such cases among the personnel of radiation-hazardous facilities and population. The necessity of developing national clinical guidelines for the prevention, diagnosis, treatment, and rehabilitation of acute radiation injury victims is substantiated. Based on an analytical review of the databases of NEB, PubMed, and Medline for 1970 to 2023 on the problem of prevention, diagnosis, treatment, and rehabilitation of individuals exposed to excess radiation and analysis of the regulatory framework governing the process of creating clinical recommendations in the Russian Federation on the provision of medical care to victims of acute radiation injuries, the main terms and their definitions relevant to acute radiation pathology were formulated, which must be unified when developing clinical recommendations. The basic classification of acute radiation lesions is presented, systematizing the variety of possible clinical forms of diseases (conditions) and their etiopathogenetic variants based on the characteristics of the types of ionizing radiation sources and individual characteristics of the conditions of acute radiation exposure. Variants of working clinical classifications of acute radiation lesions based on the generalization of the experience in the country and the world on the systematization of acute radiation pathology were determined. In general, the expediency of developing a group of clinical recommendations for the prevention, diagnosis, treatment, and rehabilitation of acute radiation injuries, covering all the various current clinical forms of diseases caused by excess (uncontrolled, unregulated, emergency) exposure, is justified. The task of determining the current list of diseases (conditions) and groups of diseases (conditions) caused by excessive human exposure in the dose range that can lead to the development of acute radiation lesions is of practical importance both for departmental medicine and the country’s healthcare system.

Optimization of Holding Force for a Climbing Robot Based on a Differential Evolutionary Algorithm

Background: The advancements in robotic technology have completely revolutionized day-to-day life. In industrial applications, the implementation of robotics is quite advantageous as it may help in performing dangerous tasks like climbing high walls, working in a high-temperature environment, high radiation exposure conditions etc. Methods: This paper presents the design and development of a wall-climbing robot for dam wall inspection using an adaptive aerodynamic adhesion technique. The optimization of a robot design is done using a differential evolutionary algorithm. Results: In the proposed model, the principle of Bernoulli adhesion is used for designing the suction pad. The optimization of various variables is done using a differential evolutionary algorithm to improve the efficiency and effectiveness of the wall climbing robot adhesion. Conclusion: The results of the proposed system show that the approach can find an optimal holding force and can be effectively used for applications like dam wall climbing for inspection.

Effect of Boric Acid on Oxidative Damage in Immunocompetent Organs under Conditions of Potassium Bichromate and Gamma Radiation Exposure

The immune system supports antigenic homeostasis in the body and regulates the processes of proliferation and differentiation of cellular components in hemo- and immunopoiesis. Chromium compounds and ionizing radiation lead to the formation of highly reactive free radicals. Sublethal dose of gamma-irradiation is characterized by a 56% decrease in thymus cellularity and a 22% decrease in lymph nodes against the background of a 44% increase in the number of lymphoid cells in the spleen. Under the combined effect of hexavalent chromium and gamma-radiation, a decrease in the number of lymphoid cells is observed. In thymus the cellularity decreases by 70%, in spleen - by 40%, in lymph nodes - by 42% in comparison with control data. Under the influence of boric acid the number of lymphoid cells in thymus significantly increases by 47%, in lymph nodes - by 14% (p<0.05) compared to the data of irradiated animals. Boric acid administration weakens the development of oxidative stress, lipid peroxidation decreases, and the activity of antioxidant defense enzymes in immunocompetent cells is increased.

Genetic polymorphisms of the folate cycle and hyperhomocysteinemia in children from areas bordering the Chоrnobyl exclusion zone

The aim of the work is to establish a relationship between polymorphisms of the FC and the state of hyperhomocysteinemia in children living in areas bordering the ChEZ). Research methods: laboratory, genetic, mathematical-statistical. Results: The levels of homocysteine (Hcy) in blood and genetic polymorphisms of the folate cycle (FC) were determined in 690 children (322 boys and 368 girls) aged 8-17 years old living near the ChEZ. It was found that 97.8% of the children had genotypes with risk alleles of FC polymorphisms. The most common combinations of 2 and 3 polymorphic variants. The proportion of hyperhomocysteinemia cases was recorded in 62.5% of those examined and did not generally depend on the number of FC polymorphisms with risk alleles. Unlike their mothers, there was no correlation between blood Hcy concentration and the number of FC polymorphisms with risk alleles in children. The frequency of hyperhomocysteinemia cases in boys was likely higher than in girls. Hyperhomocysteinemia was detected in 40% of cases among children with no risk alleles for FC genetic polymorphisms. Genotypes with allele variants of one FC polymorphism were found in 15% of cases. High frequency of hyperhomocysteinemia was recorded both in the subgroup with T/T MTHFR:677 genotype and in most genetic subgroups. A high frequency of hyperhomocysteinemia, with four polymorphisms with risk alleles, was associated with compound heterozygotes A/CMTHFR:1298 and C/TMTHFR:677 in combination with A/G MTR genotypes: A2756G and G/G A66G. The homozygous variant of the neutral allele A of the MTRR:A66G genetic polymorphism, which controls methionine synthase reductase, contributed to the improvement of Hcy methylation processes in risk allele variants of three FC polymorphisms. Conclusions: The conducted studies indicate that in children of the second Chоrnobyl generation, who have been living in conditions of constant radiation exposure in areas affected by the Chоrnobyl accident since birth, the occurrence of hyperhomocysteinemia is not associated with a specific genotype and the number of FC polymorphisms with risk alleles. The results obtained indicate the participation of genetic and environmental factors in the occurrence of hyperhomocysteinemia in the population of children living in areas located near the ChEZ.

Development of approaches to real-time optical diagnostics for laser weld formation process using laser emission spectroscopy

Welding of metals is subject to various random processes that degrade the quality of the weld, ranging from the presence of inhomogeneities in the metal to spontaneously occurring pulsating processes. Pre-weld destructive testing cannot eliminate the presence of inhomogeneities and is ineffective for spontaneous deviations in the welding process. Therefore, the development of new approaches for real-time diagnosis of the laser welding process is particularly relevant today, especially with the widespread implementation of fiber lasers. The objective of this study was to develop approaches for optical diagnostics of the process of forming heterogeneous material based on laser emission spectroscopy. An experimental setup was created to develop approaches for optical diagnostics of the process of forming heterogeneous material, which is a critical task for additive technologies and laser welding. It was demonstrated that for industrially relevant aluminum alloys 1420, 1580, AMG (Russia), it is possible to record the spectra of the gas-plasma plume that occurs when laser radiation interacts with the metal surface. These spectra depend on the radiation exposure conditions and reflect the processes of atom and molecule evaporation from the molten pool. Further research will allow establishing the nature of this connection and developing optimal modes for technological processes, enabling real-time control of these processes.

Impacts of complex electromagnetic radiation and low-frequency noise exposure conditions on the cognitive function of operators.

Both electromagnetic radiation (EMR) and low-frequency noise (LFN) are widespread and influential environmental factors, and operators are inevitably exposed to both EMR and LFN within a complex exposure environment. The potential adverse effects of such exposure on human health must be considered seriously. This study aimed to investigate the effects of EMR and LFN on cognitive function as well as their interaction effect, which remain unclear. Sixty young male college students were randomly grouped and experiments were conducted with a 2 × 2 factorial design in a shielded chamber. Mental workload (MWL) levels of the study subjects were measured and assessed using the NASA-task load index (TLX) subjective scale, an n-back task paradigm, and the functional near-infrared spectroscopy (fNIRS) imaging technique. For the 3-back task, the NASA-TLX subjective scale revealed a statistically significant main effect of LFN intensity, which enhanced the subjects' MWL level (F = 8.716, p < 0.01). Behavioral performance revealed that EMR intensity (430.1357 MHz, 10.75 W/m2) and LFN intensity (0-200 Hz, 72.9 dB) had a synergistic interaction effect, and the correct response time was statistically significantly prolonged by the combined exposure (F = 4.343, p < 0.05). The fNIRS imaging technique revealed a synergistic interaction effect between operational EMR intensity and operational LFN intensity, with statistically significant effects on the activation levels in the left and right dorsolateral prefrontal cortex (DLPFC). The mean β values of DLPFC were significantly increased (L-DLPFC F = 5.391, p < 0.05, R-DLPFC F = 4.222, p < 0.05), and the relative concentrations of oxyhemoglobin in the DLPFC were also significantly increased (L-DLPFC F = 4.925, p < 0.05, R-DLPFC F = 9.715, p < 0.01). We found a statistically significant interaction effect between EMR (430.1357 MHz, 10.75 W/m2) and LFN (0-200 Hz, 72.9 dB) when simultaneously exposing subjects to both for 30 min. We conclude that exposure to this complex environment can cause a statistically significant increase in the MWL level of operators, and even alterations in their cognitive function.

STRUCTURE AND CHARACTERISTICS OF THE CHORNOBYL NPP ACCIDENT VICTIMS ACCORDING TO THE MATERIALS OF MEDICAL EXPERTISE OF THE CAUSAL RELATIONSHIP OF DISEASES WITH THE EFFECT OF IONIZING RADIATION IN THE REMOTE POSTACCIDENTAL PERIOD (2023 year).

To study and characterize the structure of the affected categories (clean-up workers and victims) of the Chornobyl catastrophe based on the materials of expert cases of the Central Interdepartmental Expert Commission of Ministry of Health of Ukraine (CIEC) in the remote post-accidental period (2013-2023). The work was performed in the design of a retrospective study that based on analysis of the structure of all categories of Chornobyl NPP accident (ChNPP) victims during 2008-2023 years and studying of more 57 000 medical expert cases, which were considered by CIEC during 2013-2022 to establish a causal relationship between the disease and influence of radiation exposure and other harmful factors and conditions during ChNPP accident. The total number of affected adult citizens as on 01.01.2023, compared to 2008, decreased by 511,877 persons, or by 27.90 % (from 1,834,536 to 1,322,659 persons). The number of clean-up workers of the accident decreased from 276,327 (2008) to 162,180 (2023), or by 114,147 people (41.30 %), that means - during the last 15 years, almost every third-second clean-up worker who participated in the liquidation of the consequences of the accident at the ChNPP died. The number of adult victims decreased from 1,558,209 in 2008 to 1,160,479 in 2023, or by 25.52 % (397,730 persons). In the structure of medical expert cases during 2013-2022 the leading place as the reason of disease, disability and death is occupied by oncological diseases - 60.3 %, cerebrovascular diseases and their complications make up 10.00 %, diseases of the cardiovascular system - 19.6 %. In the remote post-accidental period (2013-2023) has increased the need of expertise of the causal relationship of disability and the causes of death with the influence of the ChNPP accident consequences for medical and social support. During 2013-2023 period quick reducing for all categories of affected due to the Chornobyl NPP accident taken place. In the structure of medical expert cases during 2013-2023 the leading place as the reason of disease, disability and death is occupied by oncological, cardiovascular and cerebrovascular diseases.

Властивості поверхонь деталів із криці 12Х18Н10Т, які працюють в умовах радіяційного опромінювання, відновлених методою електроіскрового леґування. Ч. 2. Особливості структурного стану, відновлених поверхонь

Властивості поверхонь деталів із криці 12Х18Н10Т, які працюють в умовах радіяційного опромінювання, відновлених методою електроіскрового леґування. Ч. 2. Особливості структурного стану, відновлених поверхонь

Radiation exposure to extremities in medical applications and its implications for the radiation protection of workers in the Philippines

In medical applications, non-homogeneous radiation exposure conditions may be encountered and whole-body monitoring alone may not be an adequate assessment of doses received by workers. This paper investigated the exposure to extremities in medical applications in the Philippines in terms of personal dose equivalent Hp(0.07). Profiles of monitored workers, dose levels, implications on optimization of occupational exposures, and factors affecting the extremity monitoring implementation were studied. The results show that <3% of workers are monitored for extremities, and there is no monitoring of eye lens dose. There is no extremity monitoring in diagnostic radiology, particularly interventional radiology. Dose levels to extremities were higher and more varied than whole-body doses. In nuclear medicine, the median annual extremity dose is 1.2 mSv, the interquartile range (IQR) is 7.6 mSv (Q1 = 0.5 mSv, Q3 = 8.1 mSv), and the maximum dose is 35 mSv. These median and IQR dose values are four and eight times higher, respectively, compared to the whole-body dose. In radiopharmaceutical distribution, the extremity median annual dose is five times higher than the whole-body dose, and the IQR value is 12 times higher where IQR is 12.1 mSv (Q1 = 0.1 mSv, Q3 = 12.2 mSv). Most notable is in cyclotron operations where <40% of workers were monitored on their extremities; however, the median dose is 100 times higher than the whole-body dose, with a maximum dose of 148 mSv. The results imply that there may be an underassessment of occupational exposure of workers in medical applications. As monitoring results are used for the establishment of a radiation protection program, lack of consideration of extremity doses can lead to inadequate measures in the optimization of worker protection. This study thus shows the need to enhance the implementation of extremity and eye lens dose monitoring in the Philippines to further strengthen the radiation protection of workers in medical applications.

Learning-based catheter and guidewire-driven autonomous vascular intervention robotic system for reduced repulsive force

Abstract Manual vascular interventional radiology (VIR) procedures have been performed under radiation exposure conditions, and many commercial master–slave VIR robot systems have recently been developed to overcome this issue. However, master–slave VIR robot systems still have limitations. The operator must reside near the master device and control the slave robot using only the master device. In addition, the operator must simultaneously process the recognition of the surgical tool from the X-ray image while operating the master device. To overcome the limitations of master–slave VIR robot systems, we propose an autonomous VIR robot system with a deep learning algorithm that excludes the master device. The proposed autonomous VIR robot with a deep learning algorithm drives surgical tools to the target blood vessel location while simultaneously performing surgical tool recognition. The proposed autonomous VIR robot system detects the location of the surgical tool based on a supervised learning algorithm, and controls the surgical tools based on a reinforcement-learning algorithm. Experiments are conducted using two types of vascular phantoms to verify the effectiveness of the proposed autonomous VIR robot system. The experimental results of the vascular phantom show a comparison between the master–slave VIR robot system and the proposed autonomous VIR robot system in terms of the repulsive force, task completion time, and success rate during the operation. The proposed autonomous VIR robot system is shown to exhibit a significant reduction in repulsive force and a 96% success ratio based on a vascular phantom.

MEDICAL EXPERTISE FOR ESTABLISH CAUSATION OF DISEASE, LEADING TO LOSS OF HEALTH, DISABILITY AND DEATH WITH THE ACTION OF IONIZING RADIATION AND OTHER HARMFUL FACTORS OF THE CHORNOBYL ACCIDENT IN THE REMOTE POST-ACCIDENTAL PERIOD (2013-2022).

To study and characterize the structure of the affected categories (clean-up workers and victims) of the Chernobyl Catastrophe based on the materials of expert cases of the Central Interdepartmental Expert Commission (CMEC) in the remote post-accidental period (2013-2022). The work was performed in the design of a retrospective study that based on studying of 50,974 expert cases, which were considered by CIEC during 2013-2022 to establish a causal relationship between the disease and influence of radiation exposure and other harmful factors and conditions during ChNPP accident using a systematic analytical approach to assessing the medical and nonmedical parameters presented in medical expert documentation. The total number of affected adult citizens as on 01.01.2022, compared to 2008, decreased by 477,953 persons, or by 26.05 % (from 1,834,536 to 1,354,746 persons). The number of clean-up workers of the accident decreased from 276,327 (2013) to 171,725 (2022), or by 104,602 people (37.85 %), that means - during the last 10 years, almost every third clean-up worker who participated in the liquidation of the consequences of the accident at the Chernobyl NPP died. The number of adult victims decreased from 1,558,209 in 2008 to 1,183,021 in 2022, or by 24.08 % (375,188 persons). The average annual reduction in the absolute number of clean-up workers of ChNPP accident during 2013-2022 is about 7,770 people per year (9,424 during 2021), adult victims - 27,045 people per year (28,922 during 2021). In the structure of medical expert cases during 2013-2022 the leading place as the reason of disease, disability and death is occupied by oncological diseases - 52.72 %, cerebrovascular diseases and their complications make up 17.08 %, diseases of the cardiovascular system - 19.6 %. In the remote post-accidental period (2013-2022) has increased the need of expertise of the causal relationship of disability and the causes of death with the influence of the Chornobyl NPP accident consequences for medical and social support. During 2013-2022 period quick reducing for all categories of affected due to the Chornobyl NPP accident taken place. In the structure of medical expert cases during 2013-2022 the leading place as the reason of disease, disability and death is occupied by oncological diseases.

Evaluating the role of the albedo of material and vegetation scenarios along the urban street canyon for improving pedestrian thermal comfort outdoors

The undeniable role of urban valleys in improving pedestrian thermal comfort along the urban streets is crucial, especially in areas with hot summers. In this research, the parameters related to thermal comfort outdoors like air temperature (Ta), surface temperature (Ts), wind speed (Ws), sky view factor (SVF), mean radiant temperature (MRT), and physiological equivalent temperature (PET) in an urban street were analyzed using ENVI-met simulation. Besides, the effects of the albedo of pavement and the percent of Fraxinous Exceliour as the dominant tree in the study area were also examined to improve thermal comfort conditions. Simultaneously with the field measurements on the site, a questionnaire was used to determine the thermal comfort range of users in urban canyons. The study also integrates with ENVI-met microclimatic modeling to improve the thermal comfort in the urban street canyon, which was used to simulate the current situation and validated with field measurements, showing a good correlation. The result has revealed that SVF is not a precise indicator for crucial radiation exposure and thermal comfort conditions despite its wide application in previous studies. Further, a notable correlation between SVF and PET is observed solely throughout sunset. Additionally, the combination of the low-albedo pavements and covering half of the street with trees (Fraxinus excelsior) can produce the most effective conditions for thermal comfort. The simulation research reveals that albedo's effect on thermal comfort is less prominent than the tree cover. However, significant changes in albedo values and a decrease in urban heat have no significant impact on improving thermal comfort in urban canyons.

Evaluation of exposure of a multidisciplinary team to ionizing radiation due to the use of fluoroscopy equipment in a surgical center.

INTRODUCTION:Ionizing radiation-producing equipment is used in surgical centers to guide invasive procedures. Technological advances have enabled improvements in image quality, which may be accompanied by increased radiation doses in the surgical team. Correct use of personal protective equipment and monitoring of radiation levels are required to a safe practice.OBJECTIVES:To evaluate radiation exposure conditions in occupationally exposed persons working at the Surgical Center at Hospital das Clínicas da Faculdade de Medicina de Botucatu for implementation of radiation protection measures.METHODS:Three different types of fluoroscopy equipment were used: C-arms, a dosimetric system with ionization chambers, and optically stimulated dosimeters. A three-stage evaluation was conducted, consisting of a first stage for observation, a second stage for estimation of kerma rate simulating exposure conditions, and a final stage for dosimetry to estimate the effective dose in workers.RESULTS:The most frequent procedures and the disposition for each team member were determined. Kerma values were estimated for both the principal physician and the assistant physician. The maximum number of annual procedures was also estimated so that the dose limits are not exceeded.CONCLUSIONS:Dosimetry for the surgical team is indicated as an approach to monitor occupational dose levels. The dose rates and effective dose found in this study are low but not negligible. Thus, proper use of equipment and periodic training for workers are still the best options for radiation protection.

Thermal protective performance of firefighting protective clothing incorporated with phase change material in fire environments

SummaryPhase change materials (PCMs) can optimize the thermal properties of fabric. Twelve kinds of microencapsulated phase change materials were selected, including four different phase change temperatures and three different content gradients. Twelve kinds of PCM‐coated fabrics were prepared by dry coating, and their basic physical properties were tested. The PCM‐coated fabric was added to the thermal protective fabric system as a comfortable layer. The thermal protective performance of the fabric system under two conditions of low‐level thermal radiation and fire exposure was analyzed through second‐degree burn time. The results showed that the incorporation of PCMs greatly improved the thermal protective performance of the fabric system under the low‐level thermal radiation, which was affected by the content, phase change temperature, mass per unit area and thermophysical properties of the coated fabric. In addition, the coated fabric by the PCMs was proved to be suitable for the condition of fire exposure, and greatly increased the thermal protective performance of the fabric system. The coated fabric with phase change temperature of 35°C and content of 45% showed the best thermal protective performance under both low‐level thermal radiation and fire exposure conditions.

Radyofrekans/Mikrodalga Elektromanyetik Radyasyonun Anksiyete ve Depresyon Üzerine Etkileri: Deneysel Hayvan Modellerine Dayalı Çalışmalara Ait Literatür Taraması

Günümüzde anksiyete ve/veya depresyon dünyada en yaygın gözlenen duygusal (emosyonel) davranış bozukluklarıdır. Bu derlemede, radyofrekans/mikrodalga-elektromanyetik radyasyonun (RF/MW-EMR) deneysel hayvan modellerinde anksiyete ve depresyon bozuklukları üzerindeki etkilerinin araştırılması amaçlanmıştır. Derlemede, 2005-2019 yılları arasında yayınlanmış toplam 31 çalışma incelenmiş olup, bu çalışmalara ait uygulanan frekans aralığı, spesifik absorbsiyon oranı, güç yoğunluğu veya elektrik alan, radyasyon maruziyet kurulumu, maruziyet süresi ve bölgesi, hayvan modeli ve yaşı, ölçülen deneysel parametreler ile çalışmaların sonuçları değerlendirilmiştir. Değerlendirilen literatür verilerindeki anksiyete ve/veya depresyon üzerine RF/MW-EMR maruziyetinin etkileri incelendiğinde, EMR’nun 19 anksiyete çalışması ile bir depresyon çalışmasında pozitif etkileri, beş anksiyete çalışması ile bir depresyon çalışmasında negatif etkileri belirlenirken, dokuz anksiyete çalışması ile üç depresyon çalışmasında EMR maruziyetinin anlamlı derecede bir etkisi gözlenmemiştir. Ayrıca değerlendirilen bu çalışmaların sekizinde, deneysel hayvan modeli özellikleri, radyasyon maruziyet koşulları, davranış testleri ve nörogelişimsel süreçlere bağlı olarak değişken sonuçlar saptanmıştır. Sonuç olarak derlemede, RF/MW-EMR maruziyetinin anksiyete ve/veya depresyon bozukluklarının oluşumunu etkileyebileceği gözlenmiş olup, literatürdeki mevcut veriler ışığında, nöral ve moleküler mekanizmalara dayalı ileri araştırmaların yararlı olabileceği düşünülmektedir.

Radiation exposure and fluoroscopically-guided interventional procedures among orthopedic surgeons in South Korea

BackgroundThe use of fluoroscopically-guided interventional (FGI) procedures by orthopedic surgeons has been increasing. This study aimed to investigate the occupational radiation exposure among orthopedic surgeons in South Korea.MethodsA nationwide survey of orthopedic surgeons was conducted in South Korea in October 2017. The dosimetry data of the participants were obtained from the National Dosimetry Registry. The orthopedic surgeons were categorized by job specialty [spine or trauma specialists, other orthopedic specialists, and residents], and descriptive statistics for the demographics and work-related characteristics were presented. Multivariable logistic regression analysis was used to evaluate the risk factors for the orthopedic surgeons who were not linked with the dosimetry data.ResultsAmong the total participants (n = 513), 40.5% of the orthopedic surgeons spent more than 50% of their time working with the FGI procedures when compared with their overall work. The average frequency of the FGI procedures among the orthopedic surgeons was 12.3 days per month. Less than 30% of the participants were regularly provided with radiation monitoring badges. The proportion of subjects who always wore lead aprons and thyroid shields were 52 and 29%, respectively. The residents group experienced more unfavorable working conditions of radiation exposure than the other specialists. The dosimetry data were not significantly linked among the residents (odds ratio [OR] 2.10, 95% confidence interval [CI] 1.11–3.95) and orthopedic surgeons working at small hospitals (OR 4.76, 95% CI 1.05–21.51).ConclusionsAlthough orthopedic surgeons often performed FGI procedures, they wore protective gear less frequently, and a large proportion of orthopedic surgeons were not monitored by the national radiation dosimetry system. As the number of radiation procedures performed by the orthopedic surgeons increases, more intensive approaches are needed to reduce radiation exposure, especially for spine and trauma surgeons.

Characterization of Bacteriophages against Pseudomonas Syringae pv. Actinidiae with Potential Use as Natural Antimicrobials in Kiwifruit Plants

Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of a bacterial canker in kiwifruit plants and has caused economic losses worldwide. Currently, the primary strategies to control this pathogen include the use of copper-based compounds and even antibiotics. However, the emergence of isolates of Psa that are resistant to these agrochemicals has raised the need for new alternatives to control this pathogen. Bacteriophages have been proposed as an alternative to control bacterial infections in agriculture, including Psa. Here, we show the isolation and characterization of 13 phages with the potential to control Psa infections in kiwifruit plants. The phages were characterized according to their host range and restriction fragment length polymorphism (RFLP) pattern. Four phages were selected according to their lytic effect on the bacteria and their tolerance to different environmental conditions of pH (4–7), temperature (4–37 °C), and solar radiation exposure (30 and 60 min). The selected phages (CHF1, CHF7, CHF19, and CHF21) were sequenced, revealing a high identity with the podophage of Psa phiPSA2. In vitro assays with kiwifruit leaf samples demonstrated that the mixture of phages reduced the Psa bacterial load within three hours post-application and was able to reduce the damage index in 50% of cases. Similarly, assays with kiwifruit plants maintained in greenhouse conditions showed that these phages were able to reduce the Psa bacterial load in more than 50% of cases and produced a significant decrease in the damage index of treated plants after 30 days. Finally, none of the selected phages were able to infect the other bacteria present in the natural microbiota of kiwifruit plants. These results show that bacteriophages are an attractive alternative to control Psa infections in kiwifruit plants.

Evaluation of the thermal indices and thermal comfort improvement by different vegetation species and materials in a medium-sized urban park

Regarding the significant impact of thermal comfort on users’ attendance in urban parks, there is an intense interest in studies on the outdoor thermal comfort in parks especially in regions with hot summers. This research examines the determinant factors of thermal environment and also strategies related to albedo and greenery in a medium-scale park using ENVI-met software. In this regard, the environmental situation is analyzed using air (Ta) and surface temperature (Ts), wind speed (WS), sky view factor (SVF), the mean radiant temperature (MRT), and physiological equivalent temperature (PET). Subsequently, low- and high-albedo pavements, plane and pine trees, and Buxus shrubs strategies are investigated that can significantly influence the parameters. According to the results, SVF is not a precise indicator for determining radiation exposure and thermal comfort conditions despite its wide application in previous studies. Further, there is a significant correlation between SVF and PET only during sunlight and sunset. In addition, the best thermal comfort condition can be reached by combining the low-albedo pavements, and trees with wide crowns and high trunks. The crown height from the ground is an important factor due to its effect on the airflow that can also counteract the impact of slightly increased radiation. Field investigation and simulation studies reveal that the effect of albedo on thermal comfort is lower than the vegetation coverage. Nevertheless, the significant changes in albedo values and urban heat island mitigation do not have any considerable effect on thermal comfort improvement in urban parks.

Radiation induced strength enhancement of sulfur polymer concrete composites based on waste and residue fillers

The behavior and properties of sulfur polymer concrete composites (SPC) based on mineral fillers (industrial waste and residues) were investigated towards potential application under high radiation exposure conditions. The composites were irradiated in a dose range up to 1.5 MGy using Co-60 gamma source. The test specimens were subjected to compressive tests, SEM analysis, capillary water absorption tests, XRD, FTIR and DSC analysis. The obtained results indicate for a high radiation resistance of investigated materials. The irradiated samples exhibit up to 35% higher compressive strength in comparison with the native samples with retaining other parameters unchanged. According to the XRD, FTIR and DSC analyzes, the proposed mechanism laying behind enhancement of mechanical properties of SPC is the sulfur polymer binder amorphization with a possible simultaneous radiation induced polymerization and/or crosslinking. The SPC materials can be considered as promising alternative for hydraulic cement concrete composites, especially in radiation and nuclear technology sectors.