Applied Radiation and Isotopes Monte Carlo Verification of Output Correction Factors for a TrueBeam STx linac

The recent publication of the new code of practice IEAA/AAPM TRS-483 introduces the use of output correction factors to correct the changes in detector response in relative dosimetry of small photon beams. In TRS-483, average correction factors are reported for several detectors at 6 and 10 MV with and without attening. These correction factors were determined by Monte Carlo simulation or experimental measurements using several linacs of di erent brands and vendors. The goal of this work was to validate the output correction factors reported in TRS-483 for a 6 MV (with and without attening lter) of a TrueBeam STx® linac with Monte Carlo simulation for four radiation detectors employed in the dosimetry of small photon beams and whose output correction factors were determined using di erent radiation source than TrueBeam STx®: PTW®31010, PTW®31016, IBA®CC-01, and IBA®SFD. The results show that Monte Carlo calculated output factors, and those reported in the code of practice TRS-483 fully agree within 1%. The use of generic correction factors for a TrueBeam STx® and the detectors studied in this work is adequate for small dosimetry static beams within the uncertainties of Monte Carlo calculations and output correction factors reported in TRS-483. Key words: TRS-483, Monte Carlo simulation, output correction factors, detector model, Phase Space File, Latent Varianc

Microplastics in the stomach contents of common dolphin (Delphinus delphis) stranded on the Galician coasts (NW Spain, 2005–2010)

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The elementary excitations of the exactly solvable Russian doll BCS model of superconductivity

The recently proposed Russian doll BCS model provides a simple example of a many body system whose renormalization group analysis reveals the existence of limit cycles in the running coupling constants of the model. The model was first studied using RG, mean field and numerical methods showing the Russian doll scaling of the spectrum, E(n) ~ E0 exp(-l n}, where l is the RG period. In this paper we use the recently discovered exact solution of this model to study the low energy spectrum. We find that, in addition to the standard quasiparticles, the electrons can bind into Cooper pairs that are different from those forming the condensate and with higher energy. These excited Cooper pairs can be described by a quantum number Q which appears in the Bethe ansatz equation and has a RG interpretation.Comment: 36 pages, 12 figure

Muon-spin relaxation investigation of magnetic bistability in a crystalline organic radical compound

We present the results of a muon-spin relaxation ($\mu^{+}$SR) investigation of the crystalline organic radical compound 4-(2-benzimidazolyl)-1,2,3,5-dithiadiazolyl (HbimDTDA), in which we demonstrate the hysteretic magnetic switching of the system that takes place at $T = 274 \pm 11\,\mathrm{K}$ caused by a structural phase transition. Muon-site analysis using electronic structure calculations suggests a range of candidate muon stopping sites. The sites are numerous and similar in energy but, significantly, differ between the two structural phases of the material. Despite the difference in the sites, the muon remains a faithful probe of the transition, revealing a dynamically-fluctuating magnetically disordered state in the low-temperature structural phase. In contrast, in the high temperature phase the relaxation is caused by static nuclear moments, with rapid electronic dynamics being motionally narrowed from the muon spectra

Comparison Between Two Warm Ischemic Models in Experimental Liver Transplantation in Pigs

Experimental models of warm ischemia in liver transplantation have been employed to study the mechanisms and treatment of ischemia reperfusion injury. METHODS: We compared a control group without (group A, n = 10) versus two models of warm ischemia of liver transplants in pigs: namely, occlusion of the hepatic artery and portal vein for 30 minutes (group B, n = 23) and extraction of the liver 60 minutes after cardiac arrest (group C, n = 5). Liver function tests, coagulation studies, and liver biopsies were performed during the first 24 hours post-liver transplant. RESULTS: Clamping of the hepatic vasculature in group B produced a significant liver injury compared with the control group: elevation of the ALT and an abnormal 1-hour post-revascularization biopsy similar to that observed in the cardiac arrest group C. The transaminase levels were lower among group A animals (P <.05). But the hepatic synthetic functions as reflected in the protrombin time (PT) were not affected in group B versus group A. The alteration in PT with respect to the initial value was similar among group A and group B animals, which were significantly less than that in group C (P <.05). CONCLUSIONS: Occlusion of the hepatic artery and portal vein, a simple surgical maneuver, causes moderate damage to a liver graft but less alteration of hepatic synthetic function. Clamping of the hepatic vasculture obtains more long-term survivors after OLT than cardiac arrest

GENERALIZED URTICARIA AS A VASCULITIC MANIFESTATION IN A PATIENT WITH SARS-CoV-2 INFECTION: A CASE REPORT IN COLOMBIA

Skin manifestations have been reported in up to 20% of cases of SARS-CoV-2 infection, including morbilliform rash (22%), pernio-like acral lesions (18%), urticaria (16%), and macular erythema (13%). It is believed that in the case of SARS-CoV-2 infection, the mechanism involved is an inflammatory response that generates immune dysregulation, vascular congestion, vasculitis, vascular thrombosis, or neoangiogenesis. This case study, present the case of a patient with no previous history of urticarial reactions, autoimmune diseases, or exposure to medications who develops generalized urticaria lasting more than 24 hours and who was diagnosed with SARS-CoV-2 infection by RT-PCR with a nasopharyngeal swab. We suggest in this patient vasculitic urticaria as a manifestation of SARS-CoV-2 infection

Lung cancer survival among Florida male firefighters

IntroductionLung cancer is a leading cause of cancer incidence and death in the United States. Although most firefighters are fit and do not smoke, they are exposed to many known carcinogens during and in the aftermath of firefighting activities. Comprehensive epidemiologic investigations on lung cancer survival for both career and volunteer firefighters have not been undertaken.MethodsData from the Florida Cancer Data System (1981–2014) were linked with firefighter certification records from the Florida State Fire Marshal’s Office to identify all patients of this occupational group; lung cancer cause-specific survival data were compared with other occupational groups using Cox regression models with occupation as the main effect. Adjusted hazard ratios (aHR) and 95% confidence intervals (95% CI) were calculated.ResultsOut of 210,541 male lung cancer cases diagnosed in Florida (1981–2014), 761 were firefighters (604 career, 157 volunteer). Lung cancer death was similar between volunteer (75.2%) and career firefighters (74.0%) but lower than non-firefighters (80.0%). Survival at 5 years was higher among firefighters (29.7%; career: 30.3%; volunteer: 27.4%) than non-firefighters (23.8%). In a multivariable model, compared with non-firefighters, firefighters have significantly higher cause-specific survival (aHR = 0.84; 95% CI: 0.77–0.91; p &lt; 0.001). However, there were no significant survival differences between career and volunteer firefighters (1.14; 0.93–1.39; p = 0.213). In a separate multivariable model with firefighters as the comparator, other broad occupational groups had significantly lower cause-specific survival [white collar: 1.11 (1.02–1.21); blue collar: 1.15 (1.05–1.25); service: 1.13 (1.03–1.25); others/unknown: 1.21 (1.12–1.32); all p-values &lt; 0.02].ConclusionLung cancer survival is significantly higher among firefighters compared with non-firefighters, but there is no significant difference between career and volunteer firefighters. Improved survival for firefighters might be due to a healthy worker effect, lower smoking prevalence relative to other worker groups, and possibly superior treatment adherence and compliance. Many firefighters are cross-trained as EMTs/paramedics and possess a level of medical knowledge that may favorably impact treatment engagement and better navigation of complex cancer care