Emerging magnetic resonance (MR) guided radiotherapy affords significantly improved anatomy visualization and, subsequently, more effective personalized treatment. The new therapy paradigm imposes ...significant demands on radiation dose calculation quality and speed, creating an unmet need for the acceleration of Monte Carlo (MC) dose calculation. Existing deep learning approaches to denoise the final plan MC dose fail to achieve the accuracy and speed requirements of large-scale beamlet dose calculation in the presence of a strong magnetic field for online adaptive radiotherapy planning. Our deep learning dose calculation method, DeepMC, addresses these needs by predicting low-noise dose from extremely noisy (but fast) MC-simulated dose and anatomical inputs, thus enabling significant acceleration. DeepMC simultaneously reduces MC sampling noise and predicts corrupted dose buildup at tissue-air material interfaces resulting from MR-field induced electron return effects. Here we demonstrate our model's ability to accelerate dose calculation for daily treatment planning by a factor of 38 over traditional low-noise MC simulation with clinically meaningful accuracy in deliverable dose and treatment delivery parameters. As a post-processing approach, DeepMC provides compounded acceleration of large-scale dose calculation when used alongside established MC acceleration techniques in variance reduction and graphics processing unit-based MC simulation.
Abstract
Getting your public health research published can be a real challenge, and the publishing process is not always clear. Often it takes a lot of time, effort and perseverance. In this ...skills-building workshop, participants will be able to learn the ropes from the Editor-in-Chief and the Publisher (OUP) of the European Journal of Public Health (EJPH), EUPHA's scientific Journal. The EJPH is a well-established multidisciplinary, Open Access journal that covers a broad scope of public health topics. It's 2021 impact factor is 4.424. The workshop will have the format of an interactive clinic and will start with short presentations by the Editor-in-Chief of the EJPH and the Publisher, on how to write, how to disseminate your findings and tools the publisher has for helping promote your research for the best impact. The Editor-in-Chief will focus on what makes manuscripts attractive to editors and reviewers, while the publisher will give an overview of the publishing process, important aspects of the wider publishing industry (including Open Access) and give authors tips of how to promote their articles post-publication. After that, there will be ample time for participants to ask their questions to the panellists. This skills-building workshop will be of interest to anyone who would like to increase their chances of getting published and who would like to learn more about creating impact with their publications. The session should in particular be helpful for young researchers who do not have a lot of publishing experience yet.
Key messages
• Think about relevance to public health, and what your research adds to science and policy.
• Think about what tools you can use to disseminate your findings.
Speakers/Panelists
Peter Allebeck
Karolinska Institute, Department of Global Public Health, Stockholm, Sweden
Rachel Moriarty
Oxford University Press, Oxford, UK
We adopted hollow 3D structures of transparent conducting oxides (TCO) for efficient emission control. TCO has high transmittance in the solar spectrum and tunable optical properties in the infrared ...regime due to their plasmonic property. The IR emissivity can be further adjusted by the geometry. Here, using solid and hollow triangles as an example, we modeled the spectral absorptance of 3D TCO structures with various carrier concentrations and geometrical factors. We showed that hollow triangular structures enhance the spectrally selective absorption, namely, high emittance in IR and low absorptance in the solar spectrum. This is because the large primary sizes of the triangles can interact strongly with the longer wavelength mid-IR while the small wall thickness of the hollow structures reduces the overall absorption volume for the shorter wavelength light in the near-IR and visible regimes. Further, by changing their angles, the hollow features can be used to tune the IR emissivity within a large range (from 0.14 to 0.8). The selective and tunable absorptance of 3D hollow structures of TCO may find applications in passive radiative cooling, solar thermal absorbing, and tunable windows glazing.
Objective: End‐stage coagulation and the structure/function of fibrin are implicated in the pathogenesis of ischemic stroke. We explored whether genetic variants associated with end‐stage coagulation ...in healthy REFVIDunteers account for the genetic predisposition to ischemic stroke and examined their influence on stroke subtype.
Methods: Common genetic variants identified through genome‐wide association studies of coagulation factors and fibrin structure/function in healthy twins (n = 2,100, Stage 1) were examined in ischemic stroke (n = 4,200 cases) using 2 independent samples of European ancestry (Stage 2). A third clinical collection having stroke subtyping (total 8,900 cases, 55,000 controls) was used for replication (Stage 3).
Results: Stage 1 identified 524 single nucleotide polymorphisms (SNPs) from 23 linkage disequilibrium blocks having significant association (p < 5 × 10–8) with 1 or more coagulation/fibrin phenotypes. The most striking associations included SNP rs5985 with factor XIII activity (p = 2.6 × 10–186), rs10665 with FVII (p = 2.4 × 10–47), and rs505922 in the ABO gene with both von Willebrand factor (p = 4.7 × 10–57) and factor VIII (p = 1.2 × 10–36). In Stage 2, the 23 independent SNPs were examined in stroke cases/noncases using MOnica Risk, Genetics, Archiving and Monograph (MORGAM) and Wellcome Trust Case Control Consortium 2 collections. SNP rs505922 was nominally associated with ischemic stroke (odds ratio = 0.94, 95% confidence interval = 0.88–0.99, p = 0.023). Independent replication in Meta‐Stroke confirmed the rs505922 association with stroke, beta (standard error, SE) = 0.066 (0.02), p = 0.001, a finding specific to large‐vessel and cardioembolic stroke (p = 0.001 and p = < 0.001, respectively) but not seen with small‐vessel stroke (p = 0.811).
Interpretation: ABO gene variants are associated with large‐vessel and cardioembolic stroke but not small‐vessel disease. This work sheds light on the different pathogenic mechanisms underpinning stroke subtype. Ann Neurol 2013
The terahertz gap is a region of the electromagnetic spectrum where high average and peak power radiation sources are scarce while at the same time scientific and industrial applications are growing ...in demand. Free-electron laser (FEL) coupling in a magnetic undulator is one of the best options for radiation generation in this frequency range, but slippage effects require the use of relatively long and low-current electron bunches to drive the terahertz FEL, limiting amplification gain and output peak power. Here we use a circular waveguide in a 0.96-m strongly tapered helical undulator to match the radiation and electron-beam velocities, allowing resonant energy extraction from an ultrashort 200-pC 5.5-MeV electron beam over an extended distance. Electron-beam spectrum measurements, supported by energy and spectral measurement of the terahertz FEL radiation, indicate an average energy efficiency of ~10%, with some particles losing >20% of their initial kinetic energy.A single-pass free-electron laser based on a waveguide in a tapered helical undulator is developed. The energy conversion efficiency from a relativistic electron beam to terahertz waves at 0.16 THz is ~10%.
We report the high-gradient tests results of a novel traveling wave accelerating structure for <inline-formula> <tex-math notation="LaTeX">\beta =0.3 </tex-math></inline-formula> based on a novel ...approach of operating at the first negative spatial harmonic. Accelerating gradients of 50 MV/m and peak electric fields of 160 MV/m were achieved in a single structure consisting of 15 coupled cells during tests at the advanced photon source. This work was performed by RadiaBeam, in collaboration with the Argonne National Laboratory, as a part of a Research and Development Program for the development of an ultrahigh-gradient linear accelerator, the Advanced Compact Carbon Ion Linac, for hadron therapy.
The distribution of risk factors for cardiovascular disease in patients aged 35–44 years who were treated for human immunodeficiency virus type 1 (HIV-1) infection was compared with that for a ...population-based cohort. HIV-1-infected men treated with a protease inhibitor-containing regimen (n = 223), compared with HIV-1-uninfected men (n = 527), were characterized by a lower prevalence of hypertension, a lower mean high-density lipoprotein cholesterol level, a higher prevalence of smoking, a higher mean waist-to-hip ratio, and a higher mean triglyceride level. No difference was found for total plasma or low-density cholesterol levels, nor for the prevalence of diabetes. Similar trends were observed among female subjects. The predicted risk of coronary heart disease was greater among HIV-1-infected men (relative risk RR, 1.20) and women (RR, 1.59; P < 10-6 for both), compared with the HIV-1-uninfected cohort. The estimated attributable risks due to smoking were 65% and 29% for HIV-1-infected men and women, respectively. Because most HIV-1-infected people will ultimately need antiretroviral therapy, risk factors for cardiovascular disease should be determined at the initiation of treatment, and interventions should be considered for all patients who have them.
Background. Even mild renal dysfunction is a predictor of cardiovascular morbidity. We investigated whether sub-threshold microalbuminuria or mildly decreased estimated glomerular filtration rate ...(eGFR) are related to left ventricular hypertrophy (LVH) in the general population. Methods. Urinary albumin-to-creatinine ratio (UACR) served to determine albuminuria, eGFR was estimated using modification of diet in renal disease (MDRD) formula, and LV geometry was assessed echocardiographically in the third MONItoring of trends and determinants in CArdiovascular disease/Cooperative Health Research in the Augsburg Area (MONICA/KORA) Augsburg survey (n = 1187). Results. The prevalence of LVH increased in parallel with UACR. Compared with the first tertile of this normal population, the age, systolic blood pressure (SBP), body mass index, gender and diabetes adjusted odds ratio (OR) for LVH was elevated already in the second (4.32–8.75 mg/g in men; 4.60–9.48 mg/g in women; OR: 2.10, P = 0.001) as well as in the third UACR-tertile (≥8.76 mg/g in men; ≥9.49 mg/g in women; OR: 1.63, P = 0.035). Likewise, adjusted SBP increased with UACR-tertiles 129 vs 132 (P = 0.036) and 137 mmHg (P < 0.001) in the first, second and third tertile, respectively, whereas diastolic blood pressure was significantly elevated only in the third UACR-tertile 79 vs 80 and 81 mmHg (P = 0.002) in the tertiles, respectively. In contrast, tertiles of eGFR or mildly impaired eGFR (<90 ml/min/1.73 m2) were not associated with the prevalence of LVH in multivariate models. Conclusions. At the general population level, even low-grade albuminuria is associated with LVH. Thus, the conventional UACR-threshold of microalbuminuria (30 mg/g) may be too conservative given that end organ damage such as LVH is observed with increased frequency at much lower levels.
Radioactive isotopes have been until now one of the most frequently used sources of gamma radiation. A broad usage of these sources is explained by their compactness, low price, and clean energy ...spectrum of radiation. Nevertheless, the modern trend set by the IAEA is to find technologies alternative to such sources owing to the hazard of emergencies, leakage, or illegal usage. Bremsstrahlung generated by electron accelerators can be used for replacement of radioactive sources. However, to efficiently compete with radioisotope sources, accelerators should feature comparable weight, dimensions, and cost. This work presents an accelerator developed by RadiaBeam to replace such radioactive isotopes as Co-60.
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