Information-Based Physics: An Observer-Centric Foundation

It is generally believed that physical laws, reflecting an inherent order in the universe, are ordained by nature. However, in modern physics the observer plays a central role raising questions about how an observer-centric physics can result in laws apparently worthy of a universal nature-centric physics. Over the last decade, we have found that the consistent apt quantification of algebraic and order-theoretic structures results in calculi that possess constraint equations taking the form of what are often considered to be physical laws. I review recent derivations of the formal relations among relevant variables central to special relativity, probability theory and quantum mechanics in this context by considering a problem where two observers form consistent descriptions of and make optimal inferences about a free particle that simply influences them. I show that this approach to describing such a particle based only on available information leads to the mathematics of relativistic quantum mechanics as well as a description of a free particle that reproduces many of the basic properties of a fermion. The result is an approach to foundational physics where laws derive from both consistent descriptions and optimal information-based inferences made by embedded observers.Comment: To be published in Contemporary Physics. The manuscript consists of 43 pages and 9 Figure

Comparison of EBT and EBT3 RadioChromic Film Usage in Parotid Cancer Radiotherapy

Background: EBT and EBT3 radioChromic films have been used in radiotherapy dosimetry for years. Objective: The aim of the current study is to compare EBT and EBT3 radioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Methods: Calibrations of EBT and EBT3 films were performed with identical setups using a 6 MV photon beam of a Siemens Primus linac. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films on a RANDO phantom. Results: While dosimetry was performed with the same conditions for the two film types for calibration and in phantom in parotid cancer radiotherapy, the measured net optical density (NOD) in EBT film was found to be higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy) with a maximum difference of 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. Conclusion: EBT film demonstrates higher NOD than EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process

Evaluation of micronuclei and antioxidant status in hospital radiation workers occupationally exposed to low-dose ionizing radiation

Abstract Purpose There is scientific evidence that ionizing radiation (IR) can be responsible for various health hazards that are one of the concerns in occupational exposure. This study was performed to evaluate DNA damage and antioxidant status in hospital workers who are occupationally exposed to low doses of IR. Materials and methods In this study, twenty occupationally exposed to low doses of IR (CT and angiography) comprising with control groups which matched them. In order to investigate the effects of chronic irradiation of radiation workers, Micronuclei (MN) frequency and the antioxidant activity of Superoxide Dismutase (SOD), Catalase (CAT) and Total Antioxidant Capacity (TAC) were measured. Then, to check adaptation against high challenge dose, the samples (in all groups) were irradiated in vitro and MN frequency was compared. Finally, to investigated the effect of the high dose after the acute and chronic low dose of ionizing radiation, MN frequency was compared in two groups (the control group that was to in-vitro irradiated (acute low dose + high dose) and radiation workers (chronic low dose + high dose)). Results MN frequency in the occupationally exposed group (n = 30) increased significantly when compared to the control group (p-value  0.05). Conclusions We observed that exposure to low doses of IR leads to increased cytogenetic damage, could not cause an adaptive-response, and improve antioxidant capacity in radiation workers. Controlling healthcare workers' exposure is the first step to improving the health of hospital workers and the quality of patient care, thus decreasing human and economic costs

Skin Dosimetry in Radiotherapy of Breast Cancer: a Comparison between EBT and EBT3 Radiochromic Films

Objective: Radiochromic EBT3 film is a later generation of radiochromic films. The aim of this study is to compare EBT and EBT3 radiochromic films in radiotherapy fields of breast cancer. Methods: A RANDO phantom was irradiated by a 6 MV Siemens Primus linac with medial and lateral fields of radiotherapy of breast cancer. Dosimetry was performed in various points in the fields using EBT and EBT3 films. Films were scanned by a Microtek color scanner. Dose values from two films in corresponding points were compared. Results: In the investigation of calibration, net optical density (NOD) of EBT radiochromic is more than the EBT3 radiochromic film. The highest percentage difference between NODs of two films is related to 0.75 Gy and equals to 14.19%. The lowest value is related to 0.2 Gy dose and is equal to 3.31%. The highest percentage difference between two films on the RANDO phantom in breast cancer fields is 13.51% and the minimum value is equal to 0.33%. Conclusion: From the comparison between the two films, most of the points show differences in dose in the measurements in fields of breast cancer radiotherapy. These differences are attributed to the thickness of the active layers, the overall thickness of the films, and the difference in the calibration fitted functions. The advantage of EBT film over EBT3 is a higher sensitivity; on the other hand EBT3 film allows to use its both sides in the scanning process and it is a new version of this film type

Analysis of Permanent Magnet Demagnetization Effect Outer-rotor Hybrid Excitation Flux Switching Motor

This paper addresses the irreversible permanent magnet (PM) demagnetization analysis of hybrid excitation flux switching motor (HEFSM) with outer-rotor configuration. PM demagnetization cause the PM strength used in the motor significantly reduces and hence contributes less torque performance. The study is focused on thermal analysis and conducted at various temperature up to as high as 180 degrees Celsius which has a tendency to be demagnetized. Therefore, PM demagnetization is among a critical issue and influences the choice of the applied motor. The analysis is carried out based on finite element method (FEM) and percentage of PM demagnetization is then calculated. Finally, based on simulated and calculated results the final design outer-rotor HEFSM has only 0.85 percent PM demagnetization at very high temperature and obviously the is no PM demagnetization at normal operating conditions

Assessment of skin dose in breast cancer radiotherapy: on-phantom measurement and Monte Carlo simulation

Aim: The main purpose of the present study is assessment of skin dose in breast cancer radiotherapy. Background: Accurate assessment of skin dose in radiotherapy can provide useful information for clinical considerations. Materials and methods: A RANDO phantom was irradiated using a 6 MV Siemens Primus linac with medial and tangential radiotherapy fields for simulating breast cancer treatment. Dosimetry was also performed on various positions across the fields using an EBT3 radiochromic film. Similar conditions of measurement on the RANDO phantom including field size, irradiation angle, number of fields, etc. were subsequently simulated via the Monte Carlo N-Particle Transport code (MCNP). Ultimately, dose values for corresponding points from both methods were compared. Results: Considering dosimetry using radiochromic films on the RANDO phantom, there were points having underdose and overdose based on the prescribed dose and skin tolerance levels. In this respect, 81.25 and 18.75 of the points had underdose and overdose, respectively. In some cases, several differences were observed between the measurement and the MCNP simulation results associated with skin dose. Conclusion: Based on the results of the points which had underdose, it was suggested that a bolus should be used for the given points. With regard to overdose points, it was advocated to consider skin tolerance dose in treatment planning. Differences between the measurement and the MCNP simulation results might be due to voxel size of tally cells in simulations, effect of beam's angle of incidence, validation time of linac's head, lack of electronic equilibrium in the build-up region, as well as MCNP tally type. © 2020 Greater Poland Cancer Centr

In vivo study of interferon-?, transforming growth factor-�, and interleukin-4 gene expression induced by radioadaptive response

Introduction: In the present study, the radioadaptive role of the immune system induced by low dose (LD) was investigated for its in vivo protective activity. Materials and Methods: Quantitative analysis of cytokine gene expression was assessed for their in vivo activity in BALB/c mice. To evaluate the adaptive response induced by LD on the mice spleen lymphocyte, the cytokine interleukin (IL)-4, interferon (IFN)-?, and transforming growth factor (TGF)-� expression was measured by a real-time quantitative polymerase chain reaction. To verify the radioadaptive effect of LD, animals were preirradiated at 10 cGy from a 60 Co source and then challenge dose at 200 cGy was delivered. Independent sample student's t-test was employed to compare cytokine gene expression in radioadaptive (10 + 200 cGy), LD (10 cGy), high-dose (HD, 200 cGy), and control groups of animals. Results: Following the HD, the cytokine gene expression of IFN-?, IL-4, and TGF-� was significantly decreased compared to the control group (P = 0.0001). However, TGF-� expression was also decreased significantly in the LD and adaptive groups compared to the control group (P = 0.0001). IFN-?/IL-4 ratio in the adaptive group was significantly decreased compared to the HD group (P = 0.0001). Conclusion: These results indicate that the immune system plays an important role for radioadaptive response induction by LD radiation to adjust the harmful effects of HD irradiation. © 2021 Journal of Cancer Research and Therapeutics | Published by Wolters Kluwer-Medknow

Crocin as a novel therapeutic agent against colitis

Ulcerative colitis is a chronic inflammatory bowel disease with high incidence and prevalence worldwide. To investigate the therapeutic potency of crocin, as a pharmacologically active component of saffron, in dextran sodium sulfate (DSS)-induced colitis mice model. Experimental colitis was induced by 7-day administration of DSS dissolved in water at a concentration of 1.5 (w/v). The animals were randomly divided into four groups (n¼6 for each group). (1) Control group received regular drinking water for four weeks, (2) the second group of mice received regular drinking water for three weeks and then received DSS for one week, (3) and (4) the other two groups received 50-ppm or 200-ppm crocin for three weeks, respectively, and then treated with DSS for one week. Our results showed that Crocin attenuates colitis disease activity index including body weight loss, diarrhea, rectal bleeding, and colon shortening in crocin pre-tread mice. Comparison of histology of colon tissues between groups showed that crocin significantly decreases colon histopathological score, at least partially, by eliciting anti-inflammatory responses in DSS-induced colitis mice. These results clearly showed that crocin is a novel therapeutic agent with low toxicity as well as great clinical significance in treatment of colitis. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group

Crocin as a novel therapeutic agent against colitis

Ulcerative colitis is a chronic inflammatory bowel disease with high incidence and prevalence worldwide. To investigate the therapeutic potency of crocin, as a pharmacologically active component of saffron, in dextran sodium sulfate (DSS)-induced colitis mice model. Experimental colitis was induced by 7-day administration of DSS dissolved in water at a concentration of 1.5 (w/v). The animals were randomly divided into four groups (n¼6 for each group). (1) Control group received regular drinking water for four weeks, (2) the second group of mice received regular drinking water for three weeks and then received DSS for one week, (3) and (4) the other two groups received 50-ppm or 200-ppm crocin for three weeks, respectively, and then treated with DSS for one week. Our results showed that Crocin attenuates colitis disease activity index including body weight loss, diarrhea, rectal bleeding, and colon shortening in crocin pre-tread mice. Comparison of histology of colon tissues between groups showed that crocin significantly decreases colon histopathological score, at least partially, by eliciting anti-inflammatory responses in DSS-induced colitis mice. These results clearly showed that crocin is a novel therapeutic agent with low toxicity as well as great clinical significance in treatment of colitis. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group