Search results for "medical physics"
showing 10 items of 579 documents
Contemporary practice and technical aspects in coronary intervention with bioresorbable scaffolds : a European perspective
2015
Aims Next to patient characteristics, the lack of a standardised approach for bioresorbable vascular scaffold (BVS) implantation is perceived as a potential explanation for the heterogeneous results reported so far. To provide some guidance, we sought to find a consensus on the best practices for BVS implantation and management across a broad array of patient and lesion scenarios. Methods and results Fourteen European centres with a high volume of BVS procedures combined their efforts in an informal collaboration. To get the most objective snapshot of different practices among the participating centres, a survey with 45 multiple choice questions was prepared and conducted. The results of th…
New imaging techniques and opportunities in endoscopy.
2011
Gastrointestinal endoscopy is undergoing major improvements, which are driven by new available technologies and substantial refinements of optical features. In this Review, we summarize available and evolving imaging technologies that could influence the clinical algorithm of endoscopic diagnosis. Detection, characterization and confirmation are essential steps required for proper endoscopic diagnosis. Optical and nonoptical methods can help to improve each step; these improvements are likely to increase the detection rate of neoplasias and reduce unnecessary endoscopic treatments. Furthermore, functional and molecular imaging are emerging as new diagnostic tools that could provide an oppor…
Self-similar focusing with generalized devil's lenses
2011
[EN] We introduce the generalized devil's lenses (GDLs) as a new family of diffractive kinoform lenses whose structure is based on the generalized Cantor set. The focusing properties of different members of this family are analyzed. It is shown that under plane wave illumination the GDLs give a single main focus surrounded by many subsidiary foci. It is shown that the total number of subsidiary foci is higher than the number of foci corresponding to conventional devil's lenses; however, the self-similar behavior of the axial irradiance is preserved to some extent. (C) 2011 Optical Society of America
Fourier optical approach to the extraction of morphological parameters from the diffraction pattern of biological cells.
1978
A new procedure for fast quantitative extraction of cell parameters from diffraction patterns was deduced from model calculations and applied to cervical gynecological material. Based on radial scans of the diffraction pattern, the technique permits simultaneous determination of the nuclear and cytoplasmic diameters by Fourier analysis of the radial scanning signals after compensation for the intensity falloff by an amplification proportional to the third power of the radial position in the diffraction plane. Illustrative examples of measurements on exfoliated cells of different types are presented.
Shear banding mechanism of plastic deformation in LiF irradiated with swift heavy ions
2012
The effect of ion irradiation on the behavior of plastic deformation at micro- and nanoindentation on (001) face of LiF has been investigated. The irradiation was performed using heavy ions (U, Au, Ti and S) with energy in the range from 3 MeV to 2 GeV at fluences up to 5x1013 ions/cm2. In non-irradiated LiF, the indentation produces dislocation gliding on the {110} planes along the and directions. At high fluence irradiation, the resource of the dislocation slip along the preferable directions becomes exhausted due to immobilization of dislocations by radiation defects and their aggregates. The present study demonstrates the change of the mechanism of plastic deformation from homogenous di…
SPCCTDM, a Catalogue for Analysis of Therapeutic Drug Monitoring Related Contents in the Drug Prescription Information
2010
Therapeutic drug monitoring (TDM) has consistently been shown to be useful for optimization of drug therapy. For the first time, a method has been developed for the text analysis of TDM in SPCs in that a catalogue SPC-ContentTDM (SPCCTDM) provides a codification of the content of TDM in SPCs. It consists of six structure-related items (dose, adverse drug reactions, drug interactions, overdose, pregnancy/breast feeding, and pharmacokinetics) according to implicit or explicit references to TDM in paragraphs of the SPC, and four theory-guided items according to the information about ranges of plasma concentrations and a recommendation of TDM in the SPC. The catalogue is regarded as valid for t…
Educational value of surgical videos on YouTube: quality assessment of laparoscopic appendectomy videos by senior surgeons vs. novice trainees
2019
Background To prepare for surgery, surgeons often recur to surgical videos, with YouTube being reported as the preferred source. This study aimed to compare the evaluation of three surgical trainees and three senior surgeons of the 25 most viewed laparoscopic appendectomy videos listed on YouTube. Additionally, we assessed the video conformity to the published guidelines on how to report laparoscopic surgery videos (LAP-VEGaS). Methods Based on the number of visualization, the 25 most viewed videos on laparoscopic appendectomy uploaded on YouTube between 2010 and 2018 were selected. Videos were evaluated on the surgical technical performance (GOALS score), critical view of safety (CVS), and…
Monte Carlo simulation of energy absorbed in phenolic ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons
2017
Abstract In this work analyses of the energy released per unit mass in phenolic compound exposed to neutron beams were performed with the aim of predicting the increase in dose achievable by addition of gadolinium (Gd) inside the pellets. In particular, Monte Carlo (MC) simulations were carried out for IRGANOX® 1076 phenolic compound irradiated with neutron beams with different energy spectra at various depths inside a water phantom. The addition of gadolinium increases sensitivity of phenolic ESR (electron spin resonance) dosimeters to neutrons thanks to the high gadolinium cross section for neutron capture and to the large number of secondary particles (mainly Auger and internal conversio…
The Influence of All-Night Exposure to Pulsed Radiofrequency Electromagnetic Fields on Human Sleep. Der Einfluss kontinuierlicher nachtlicher Exposit…
2005
Question of the study The widespread use of mobile telephones has led to public discussion about the putative health hazards as well as scientific interest in the interactions of pulsed, high-frequency electromagnetic fields with physiological systems. This article presents a survey of three consecutive studies carried out by a research group at the University of Mainz.
GPCALMA, a mammographic CAD in a GRID connection
2003
Purpose of this work is the development of an automatic system which could be useful for radiologists in the investigation of breast cancer. A breast neoplasia is often marked by the presence of microcalcifications and massive lesions in the mammogram: hence the need for tools able to recognize such lesions at an early stage. GPCALMA (Grid Platform Computer Assisted Library for MAmmography), a collaboration among italian physicists and radiologists, has built a large distributed database of digitized mammographic images (at this moment about 5500 images corresponding to 1650 patients). This collaboration has developed a CAD (Computer Aided Detection) system which, installed in an integrated…