Search results for " method"

A dosimetric study of Leipzig applicators.

2005

Purpose: To obtain the absolute dose-rate distribution in liquid water for all six cup-shaped Leipzig applicators by means of an experimentally validated Monte Carlo (MC) code. These six applicators were used in high-dose-rate (HDR) afterloaders with the “classic” and v2 192Ir sources. The applicators have an inner diameter of 1, 2, and 3 cm, with the source traveling parallel or perpendicular to the contact surface. Methods and materials: The MC GEANT4 code was used to obtain the dose-rate distribution in liquid water for the six applicators and the two HDR source models. To normalize the applicator output factors, a MC simulation for the “classic” and v2 sources in air was performed to es…

Cell volume homeostatically controls the rDNA repeat copy number and rRNA synthesis rate in yeast

2021

[Abstract] The adjustment of transcription and translation rates to the changing needs of cells is of utmost importance for their fitness and survival. We have previously shown that the global transcription rate for RNA polymerase II in budding yeast Saccharomyces cerevisiae is regulated in relation to cell volume. Total mRNA concentration is constant with cell volume since global RNApol II-dependent nascent transcription rate (nTR) also keeps constant but mRNA stability increases with cell size. In this paper, we focus on the case of rRNA and RNA polymerase I. Contrarily to that found for RNA pol II, we detected that RNA polymerase I nTR increases proportionally to genome copies and cell s…

Assembling a consensus on actinic cheilitis: A Delphi study.

2021

Aims: To discuss the terminology to define and classify actinic cheilitis (AC) and to build a consensus on the diagnostic and therapeutic approaches to AC. Methods: Two-round Delphi study using a questionnaire including 34 closed sentences (9 on terminology and taxonomy, 5 on potential for malignant transformation, 12 on diagnostic aspects, 8 on treatment) and 8 open questions. Experts’ agreement was rated using a Likert scale (1–7). Results: A consensus was reached on 24 out 34 statements (73.5%) and on 5 out of 8 (62.5%) close-ended questions. The response rate was identical in both rounds (attrition of 0%). AC is the term with the highest agreement (median of 7 (strongly agree; IQR: 6–7)…

Improved inter-observer agreement of an expert review panel in an oncology treatment trial--Insights from a structured interventional process.

2015

Abstract Purpose Oncologic imaging is a key for successful cancer treatment. While the quality assurance (QA) of image acquisition protocols has already been focussed, QA of reading and reporting offers still room for improvement. The latter was addressed in the context of a prospective multicentre trial on fluoro-deoxyglucose (FDG)–positron-emission tomography (PET)/CT-based chemoradiotherapy for locally advanced non-small cell lung cancer (NSCLC). Material and methods An expert panel was prospectively installed performing blinded reviews of mediastinal NSCLC involvement in FDG–PET/CT. Due to a high initial reporting inter-observer disagreement, the independent data monitoring committee (I…

The effect of overall treatment time in radiotherapy for localized prostate carcinoma

1991

Educational needs in gastrointestinal cancer: a consensus position paper from the ESMO Gastrointestinal Cancer Faculty

2019

Gastrointestinal (GI) cancers are common in all parts of the world. Effective prevention and early detection of GI cancers are not universally implemented. Therefore, it must be anticipated that the incidence and the mortality of GI cancers will remain high within the next decades. The European Society for Medical Oncology (ESMO) Gastrointestinal Cancer Faculty aims to increase the skills of medical oncologists and other disciplines involved in treating GI malignancies. We aimed to increase the survival chances for patients with GI cancers, augment their quality of life and enable successful return to normal social and professional life during the period of survivorship. ESMO also aims to d…

Monte Carlo Simulation of Alloy Phase Diagrams and Short-Range Order

1986

As a prototype model for order-disorder phenomena in binary alloys, a face-centered cubic lattice is considered,the sites of which can be taken by either A-atoms or B-atoms, assuming pair-wise interactions between nearest (J) and next nearest neighbours (J). The phase diagram is constructed from Monte Carlo calculations. Some technical aspects essential for the success of such calculations are briefly mentioned (use of grand-canonical rather than canonical ensemble, how to obtain the free energy needed to locate first-order phase transitions, etc.). It is shown that the topology of the phase diagram changes when the ratio R = Jnnn/Jnn is varied, and this behaviour is discussed in the contex…

Replica-exchange molecular dynamics simulation for supercooled liquids

2000

We investigate to what extend the replica-exchange Monte Carlo method is able to equilibrate a simple liquid in its supercooled state. We find that this method does indeed allow to generate accurately the canonical distribution function even at low temperatures and that its efficiency is about 10-100 times higher than the usual canonical molecular dynamics simulation.

Classical and Quantum Two-Dimensional Fluids in the Gibbs Ensemble

1994

We study the properties of model fluids in two spatial dimensions with Gibbs ensemble Monte Carlo (GEMC) techniques. In particular in the first part of the paper we study the entropy driven phase separation in case of a nonadditive symmetric hard disc fluid and locate by a combination of GEMC with finite size scaling techniques the critical line of nonadditivities as a function of the system density, which separates the mixing/demixing regions, we compare with a simple approximation. In the second part we successfully combine path integral Monte Carlo (PIMC) and GEMC techniques in order to locate the gas-liquid coexistence densities for a fluid with classical degrees of freedom and internal…

Anomalous size-dependence of interfacial profiles between coexisting phases of polymer mixtures in thin-film geometry: A Monte Carlo simulation

1997

The interfacial profile between coexisting phases of a binary mixture (A,B) in a thin film of thickness D and lateral linear dimensions L depends sensitively on both linear dimensions and on the nature of boundary conditions and statistical ensembles applied. These phenomena generic for systems in confined geometry are demonstrated by Monte-Carlo simulations of the bond fluctuation model of symmetric polymer mixtures. Both the canonical and semi-grand-canonical ensemble are studied. In the canonical ensemble, the interfacial width w increases (from small values which are of the same order as the intrinsic profile) like sqrt{D}, before a crossover to a saturation value w_max (w_max^2 proport…