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This study presents several methods to evaluate the exergy of thermal and nuclear radiation. First, a general treatment is developed for the thermal radiation exergy flux. Second, the exergy of thermal radiation is derived from a ...
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This study presents several methods to evaluate the exergy of thermal and nuclear radiation. First, a general treatment is developed for the thermal radiation exergy flux. Second, the exergy of thermal radiation is derived from a simple, general, original thermodynamic argument. Third, the state of the art concerning the accurate upper bounds for the conversion efficiency of thermal radiation into work is briefly presented. Fourth, the exergy of nuclear radiation is derived.
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Background and Aims:? Exposure to ionising radiation to Anaesthesiology consultants, residents, technicians and nurses (Anaesthesiology personnel) is steadily increasing as a consequence of growing usage of imaging technology for ...
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Background and Aims:? Exposure to ionising radiation to Anaesthesiology consultants, residents, technicians and nurses (Anaesthesiology personnel) is steadily increasing as a consequence of growing usage of imaging technology for diagnostic and therapeutic purposes. We conducted a questionnaire-based survey of Anaesthesiology professionals (consultants, residents, technicians and nursing staff) working in three major tertiary care medical institutes in northern India regarding the existing knowledge, attitudes and practices of radiation safety at their workplaces. Methods:? A printed and validated 30-point questionnaire was distributed. Questions were graded into the domains of demographics (6 questions), knowledge (9 questions), attitude (4 questions) and practice (11 questions). Data obtained from the responses was collated and analysed statistically Results:? Out of the 403 questionnaires distributed, 222 were returned completed (55%). Majority of the respondents were residents (53.60%) and males (57.20%). Many were unaware of the principle of As Low As Reasonably Achievable (ALARA), (70.7%) regarding collimators (65.85%) and their usage (41.9%). Maximum respondents stressed on the necessity of knowing the exposure dosage of radiations (89.2%) and were concerned regarding the same (87.8%). Lead apron was the commonest protection equipment and 97.3% of them were not using dosimeters. Highest levels of knowledge, attitude, and practices were demonstrated by the consultants. In terms of practices, the technicians fared better than the residents. Conclusion:? Knowledge, attitude and practices regarding radiation protection issues and doses of radiological procedures is limited. Although all the cadres scored high on their attitude scores, the practice sector requires improvement.
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Appropriate models are essential for making the transition from scientific discoveries to meaningful applications of the knowledge for human use. Acute as well as delayed effects of ionising radiation to the biological systems dev...
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Appropriate models are essential for making the transition from scientific discoveries to meaningful applications of the knowledge for human use. Acute as well as delayed effects of ionising radiation to the biological systems develop hierarchically starting from damage to the vital macromolecules up to the disturbances caused at the whole organism level. In vitro models like bacteria, yeast, various mammalian cells cultured as monolayers (2-D) and spheroids (3-D) as well as cells with specific genetic alterations have provided insight into the complex relationships between damage induction and various signal transduction pathways, allowing identification of molecular and sub-cellular targets vital to the fate of irradiated cells. On the other hand, in vivo models (multicellular whole organisms), ranging from simple worms to non-human primates, have been gainfully employed to evaluate efficacy as well as toxicity of potential countermeasure agents (molecules, combinations and formulated preparations) facilitating their deployment in human subjects. This review provides a brief account of the efforts with various in vitro and in vivo models for understanding the biological basis of radiation damage as well as the development of radiation countermeasures, viz., protectors, mitigators and therapeutics.
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There is widespread interest in the development of tools to estimate radiation exposures. Exhaled breath provides a novel matrix for assessing biomarkers that could be correlated with exposures. The use of exhaled breath for estim...
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There is widespread interest in the development of tools to estimate radiation exposures. Exhaled breath provides a novel matrix for assessing biomarkers that could be correlated with exposures. The use of exhaled breath for estimating radiation exposure is warranted, as studies have shown that external exposure to ionizing radiation causes oxidative stress that accelerates lipid peroxidation of polyunsaturated fatty acids, liberating alkanes and alkane metabolites that are excreted in the breath as volatile organic compounds (VOCs). As a proof of principle study, small groups (n = 4) of Gottingen minipigs were whole-body irradiated with gamma rays delivered by a Co-60 source at absorbed doses of 0, 0.25, 0.5, 0.75, 1, 1.25, 2, and 4 Gy. Additional groups (n = 4) were treated with lipopolysaccharide (LPS) or granulocyte colony stimulating factor (G-CSF), with and without concurrent Co-60 exposure, at an absorbed dose of 1 Gy. Breath and background air VOC samples were collected on days -3, -2, -1, 0 pre-irradiation, then at 0.25, 24, 48, 72, and 168 h postirradiation. VOCs were analyzed by automated thermal desorption with two-dimensional gas chromatography and time-of-flight mass spectrometry (ATD GCxGC TOF MS). The results show significant changes in 58 breath VOCs post-irradiation, mainly consisting of methylated and other derivatives of alkanes, alkenes, and benzene. Using a multivariate combination of these VOCs, a radiation response function was constructed, which was significantly elevated at 15 min post irradiation and remained elevated throughout the study (to 168 h post irradiation). As a binary test of radiation absorbed doses >= 0.25 Gy, the radiation response function distinguished irradiated animals fromshams (0 Gy) with 83-84% accuracy. A randomly derived radiation response function was robust: When half of the biomarkers were removed, accuracy was 75%. An optimally derived function with two biomarkers was 82% accurate. As a binary test of radiation absorbed doses >= 0.5 Gy, the radiation response function identified irradiated animals with an accuracy of 87% at 15 min post irradiation and 75.5% at 168 h post irradiation. Treatment with LPS and G-CSF did not affect the radiation response function. This proof-of-principle study supports the hypothesis that breath VOCs may be used for estimating radiation exposures. Further studies will be required to validate the sensitivity and specificity of these potential biomarkers.
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Society's and individuals' concerns about the adverse effects from radiation are logically amplified many times when radiological terrorism is considered. The spectrum of events include industrial sabotage, the use of an explosive...
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Society's and individuals' concerns about the adverse effects from radiation are logically amplified many times when radiological terrorism is considered. The spectrum of events include industrial sabotage, the use of an explosive or non_explosive radiological dispersal device, the placement of a radiological exposure device in a public facility and the use of an improvised nuclear device. The consequences of an event relate to the physical and medical damage of the event itself, the financial impact, and the acute and long-term medical consequences, including fear of radiation-induced cancer. The magnitude of a state-sponsored nuclear event is so great that limited detailed response planning had been done in the past, as compared to the work now ongoing. Planning is done on the basis of scenario modelling. Medical response planning includes medical triage, distribution of victims to care by experienced physicians, developing medical countermeasures to mitigate or treat radiation injury, counselling and appropriately following exposed or potentially exposed people, and helping the local community develop confidence in their own response plan. Optimal response must be based on the best available science. This requires scientists who can define, prioritise and address the gaps in knowledge with the range of expertise from basic physics to biology to translational research to systems expertise to response planning to healthcare policy to communications. Not only are there unique needs and career opportunities, but there is also the opportunity for individuals to serve their communities and country with education regarding radiation effects and by formulating scientifically based government policy.
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The benefit of radiation is immense in the field of gastroenterology. Radiation is used daily in different gastrointestinal imaging and diagnostic and therapeutic interventional procedures. Radiotherapy is one of the primary modal...
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The benefit of radiation is immense in the field of gastroenterology. Radiation is used daily in different gastrointestinal imaging and diagnostic and therapeutic interventional procedures. Radiotherapy is one of the primary modalities of treatment of gastrointestinal malignancies. There are various modalities of radiotherapy. Radiotherapy can injure malignant cells by directly damaging DNA, RNA, proteins, and lipids and indirectly by forming free radicals. External beam radiation, internal beam radiation and radio-isotope therapy are the major ways of delivering radiation to the malignant tissue. Radiation can also cause inflammation, fibrosis, organ dysfunction, and malignancy. Patients with repeated exposure to radiation for diagnostic imaging and therapeutic procedures are at slightly increased risk of malignancy. Gastrointestinal endoscopists performing fluoroscopy-guided procedures are also at increased risk of malignancy and cataract formation. The radiological protection society recommends certain preventive and protective measures to avoid side effects of radiation. Gastrointestinal complications related to radiation therapy for oncologic processes, and exposure risks for patients and health care providers involved in diagnostic or therapeutic imaging will be discussed in this review.Copyright 2022, Ahmed et al.
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Objective: To evaluate the knowledge and current radiation safety practice among health care professionals undertaking fluoroscopic procedures in urology.
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The use of ionizing radiation for medical diagnostic tests and interventional procedures has grown substantially over the past 2 decades, and there is now considerable concern expressed in both the medical literature and the lay p...
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The use of ionizing radiation for medical diagnostic tests and interventional procedures has grown substantially over the past 2 decades, and there is now considerable concern expressed in both the medical literature and the lay press of the harmful effects of radiation exposure. Although there is some controversy regarding whether this medical radiation is actually harmful, minimizing the dose to the patient is logical and a basic part of proper care. To do this, clinicians must have an understanding of the amount of radiation that is involved with each test. Physicians have a responsibility to keep the level of radiation exposure as low as reasonably achievable. A number of simple and common sense measures can help achieve this goal. Encouragingly, there are also numerous new technologies which can substantially lower radiation dose, especially in cardiovascular studies. This review will highlight various ways to reduce radiation in cardiovascular imaging.
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Ionizing radiation-induced Acute Radiation Syndrome (ARS) can be prevented/treated using radioprotective agents including; radioprotectors, radiomitigators and radio-therapeutics. Most of the radioprotective molecules currently be...
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Ionizing radiation-induced Acute Radiation Syndrome (ARS) can be prevented/treated using radioprotective agents including; radioprotectors, radiomitigators and radio-therapeutics. Most of the radioprotective molecules currently being developed have emerged from classical drug discovery approaches and have certain shortcomings related to efficacy and toxicity. In order to overcome these issues, adoption of new target-based drug development approaches is required. Like other pharmaceutical drug development programs, patents are being used to protect the new radioprotective compounds that provide right of exclusivity to the inventors. In addition to patents, the FDA approval for safety and efficacy is required for the development of radioprotective drugs that is often being done under FDA's animal rule and requires huge amount of funding. However, radiation countermeasure agents considered emergency medicines and not carrying attractive revenue generation opportunities and are often granted 'orphan drug status'. Thus, pharma giants do not take much interest in such molecules that limit the funding options only to the government agencies, which in turn reduces the interest of researchers in this particular area. In addition to their emergency use, these agents could also be employed for clinical radiotherapy purposes and may provide reasonable incentive to the inventor. Thus, encouraging the development of new radioprotective agent with cutting-edge drug discovery approaches needs more public-private partnership ensuring affordable access; that may stimulate researchers to engage in the area of radioprotector development. This article attempts to cover information available so far on the products/patents/major compounds, known in this critical area of development, along with most relevant regulatory issues and future perspectives.
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An updated review of on-orbit measurements for multiple pFET dosimeters at GEO for 1998–2007 time period indicates excellent sensor performance over a range of dose rates and yields valuable information regarding space environmen...
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An updated review of on-orbit measurements for multiple pFET dosimeters at GEO for 1998–2007 time period indicates excellent sensor performance over a range of dose rates and yields valuable information regarding space environment model (AE-8, AE-9, IGE-2006, and POLE)/transport tool validation.
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