352 research outputs found

    Stereotactic ablative body radiotherapy combined with immunotherapy: Present status and future perspectives

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    Radiotherapy is along with surgery and chemotherapy one of the prime treatment modalities in cancer. It is applied in the primary, neoadjuvant as well as the adjuvant setting. Radiation techniques have rapidly evolved during the past decade enabling the delivery of high radiation doses, reducing side-effects in tumour-adjacent normal tissues. While increasing local tumour control, current and future efforts ought to deal with microscopic disease at a distance of the primary tumour, ultimately responsible for disease-progression. This review explores the possibility of bimodal treatment combining radiotherapy with immunotherapy

    Two-dimensional interactions between a BF-type theory and a collection of vector fields

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    Consistent interactions that can be added to a two-dimensional, free abelian gauge theory comprising a special class of BF-type models and a collection of vector fields are constructed from the deformation of the solution to the master equation based on specific cohomological techniques. The deformation procedure modifies the Lagrangian action, the gauge transformations, as well as the accompanying algebra of the interacting model.Comment: LaTeX 2e, 31 page

    Relativistic Quantum Measurements, Unruh effect and Black Holes

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    It is shown how the technique of restricted path integrals (RPI) or quantum corridors (QC) may be applied for the analysis of relativistic measurements. Then this technique is used to clarify the physical nature of thermal effects as seen by an accelerated observer in Minkowski space-time (Unruh effect) and by a far observer in the field of a black hole (Hawking effect). The physical nature of the "thermal atmosphere" around the observer is analysed in three cases: a) the Unruh effect, b) an eternal (Kruskal) black hole and c) a black hole forming in the process of collapse. It is shown that thermal particles are real only in the case (c). In the case (b) they cannot be distinguished from real particles but they do not carry away mass of the black hole until some of these particles are absorbed by the far observer. In the case (a) thermal particles are virtual.Comment: 24 pages (Latex), 8 EPS figures The text was edited for the new versio

    Фінансовий контролінг як інструмент управління діяльністю суб'єкта господарювання

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    PURPOSE: Multiple imaging techniques are nowadays available for clinical in-vivo visualization of tumour biology. FDG PET/CT identifies increased tumour metabolism, hypoxia PET visualizes tumour oxygenation and dynamic contrast-enhanced (DCE) CT characterizes vasculature and morphology. We explored the relationships among these biological features in patients with non-small-cell lung cancer (NSCLC) at both the patient level and the tumour subvolume level. METHODS: A group of 14 NSCLC patients from two ongoing clinical trials (NCT01024829 and NCT01210378) were scanned using FDG PET/CT, HX4 PET/CT and DCE CT prior to chemoradiotherapy. Standardized uptake values (SUV) in the primary tumour were calculated for the FDG and hypoxia HX4 PET/CT scans. For hypoxia imaging, the hypoxic volume, fraction and tumour-to-blood ratio (TBR) were also defined. Blood flow and blood volume were obtained from DCE CT imaging. A tumour subvolume analysis was used to quantify the spatial overlap between subvolumes. RESULTS: At the patient level, negative correlations were observed between blood flow and the hypoxia parameters (TBR >1.2): hypoxic volume (−0.65, p = 0.014), hypoxic fraction (−0.60, p = 0.025) and TBR (−0.56, p = 0.042). At the tumour subvolume level, hypoxic and metabolically active subvolumes showed an overlap of 53 ± 36 %. Overlap between hypoxic sub-volumes and those with high blood flow and blood volume was smaller: 15 ± 17 % and 28 ± 28 %, respectively. Half of the patients showed a spatial mismatch (overlap <5 %) between increased blood flow and hypoxia. CONCLUSION: The biological imaging features defined in NSCLC tumours showed large interpatient and intratumour variability. There was overlap between hypoxic and metabolically active subvolumes in the majority of tumours, there was spatial mismatch between regions with high blood flow and those with increased hypoxia. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00259-015-3169-4) contains supplementary material, which is available to authorized users

    Epigenetics in radiotherapy: Where are we heading?

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    Radiotherapy is an important component of anti-cancer treatment. However, not all cancer patients respond to radiotherapy, and with current knowledge clinicians are unable to predict which patients are at high risk of recurrence after radiotherapy. There is therefore an urgent need for biomarkers to guide clinical decision-making. Although the importance of epigenetic alterations is widely accepted, their application as biomarkers in radiotherapy has not been studied extensively. In addition, it has been suggested that radiotherapy itself introduces epigenetic alterations. As epigenetic alterations can potentially be reversed by drug treatment, they are interesting candidate targets for anticancer therapy or radiotherapy sensitizers. The application of demethylating drugs or histone deacetylase inhibitors to sensitize patients for radiotherapy has been studied in vitro, in vivo as well as in clinical trials with promising results. This review describes the current knowledge on epigenetics in radiotherapy

    BRST quantization of anomalous gauge theories

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    It is shown how the BRST quantization can be applied to a gauge invariant sector of theories with anomalously broken symmetries. This result is used to show that shifting the anomalies to a classically trivial sector of fields (Wess-Zumino mechanism) makes it possible to quantize the physical sector using a standard BRST procedure, as for a non anomalous theory. The trivial sector plays the role of a topological sector if the system is quantized without shifting the anomalies.Comment: 16 pages, latex, revised and enlarged version to appear in Phys.Rev.

    E6,7,8 Magnetized Extra Dimensional Models

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    We study 10D super Yang-Mills theory with the gauge groups E6E_6, E7E_7 and E8E_8. We consider the torus/orbifold compacfitication with magnetic fluxes and Wilson lines. They lead to 4D interesting models with three families of quarks and leptons, whose profiles in extra dimensions are quasi-localized because of magnetic fluxes.Comment: 17 pages, 1 figur

    Mesoscopic Klein-Schwinger effect in graphene

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    Strong electric field annihilation by particle-antiparticle pair creation, described in detail by Sauter and Schwinger, is a basic non-perturbative prediction of quantum electrodynamics. Its experimental demonstration remains elusive as Schwinger fields ESE_S are beyond reach even for the light electron-positron pairs. Here we put forward a mesoscopic variant of the Schwinger effect in graphene, which hosts Dirac fermions with electron-hole symmetry. Using DC transport and RF noise, we report on universal 1d-Schwinger conductance at the pinch-off of ballistic graphene transistors. Strong pinch-off electric fields are concentrated in a length Λ0.1  μm\Lambda\gtrsim 0.1\;\mathrm{\mu m} at the transistor drain, and induce Schwinger e-h pair creation at saturation, for a Schwinger voltage VS=ESΛV_S=E_S\Lambda on the order of the pinch-off voltage. This Klein-Schwinger effect (KSE) precedes an instability toward an ohmic Zener regime, which is rejected at twice the pinch-off voltage in long devices. The KSE not only gives clues to current saturation limits in ballistic graphene, but also opens new routes for quantum electrodynamic experiments in the laboratory.Comment: 32 pages, 11 figures, updated to include the link to the set of experimental data on the Zenodo deposit at DOI 10.5281/zenodo.710463

    National societies' needs as assessed by the ESTRO National Societies Committee survey: A European perspective

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    Purpose: To determine how ESTRO can collaborate with Radiation Oncology National Societies (NS) according to its mission and values, and to define the new roadmap to strengthen the NS network role in the forthcoming years. Materials and methods: The ESTRO NS committee launched a survey addressed to all European National Societies, available online from June 5th to October 30th 2018. Questions were divided into three main sections: (1) general information about NS; (2) relevant activities (to understand the landscape of each NS context of action); (3) relevant needs (to understand how ESTRO can support the NS). Eighty-nine European NS were invited to participate. Respondents were asked to rank ESTRO milestones in order of importance, indicating the level of priority to their society. Results: A total of 58 out of 89 NS (65.2%) from 31 European countries completed the questionnaire. The majority of NS ranked “Optimal patient care to cure cancer and to reduce treatment-related toxicity” as the highest level of priority. This aligns well with the ESTRO vision 2030 “Optimal health for all together.” NS also indicated a high need for more consensus guidelines and exchange of best practices, access to high quality accredited education, implementation of the ESTRO School Core Curriculum at the national level, and defining quality indicators and standard in Radiation Oncology, improved communication and increased channelling of information. Conclusion: The results of this survey will be used to strengthen the relations between ESTRO and European NS to promote and develop initiatives to improve cancer care

    BTZ Black Hole as Solution of 3d Higher Spin Gauge Theory

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    BTZ black hole is interpreted as exact solution of 3d higher spin gauge theory. Solutions for free massless fields in BTZ black hole background are constructed with the help of the star-product algebra formalism underlying the formulation of 3d higher spin theory. It is shown that a part of higher spin symmetries remains unbroken for special values of the BTZ parameters.Comment: 31 pages, LaTeX; references correcte
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