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Formulas for calculation

Andre Beckus, Alexandru Tamasan, Aristide Dogariu, Ayman F Abouraddy, George K Atia
Analytic expressions of the spatial coherence of partially coherent fields propagating in the Fresnel regime in all but the simplest of scenarios are largely lacking, and calculation of the Fresnel transform typically entails tedious numerical integration. Here, we provide a closed-form approximation formula for the case of a generalized source obtained by modulating the field produced by a Gauss-Shell source model with a piecewise constant transmission function, which may be used to model the field's interaction with objects and apertures...
December 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Shanal S Kumar, Bradford A Moffat, Simon Salinas, Leonid Churilov, Bernard Yan
BACKGROUND: There is emerging interest in the relationship between neuroimaging location of lacunar infarcts and underlying stroke risk factors. Recent methods used for localization of lacunar infarcts are affected by high inter-rater variability. We used a novel algorithm-driven method that provided quantitative assessment of the distance of the lacunar infarct from the origins of the lenticulostriate arteries. METHODS: We conducted a retrospective analysis of patients who presented with lacunar infarcts between 2007 and 2011...
November 24, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Junaid Ahmad, Anees Ahmad, Mokbul Morshed Ahmad, Nafees Ahmad
Millions of people are currently displaced from their homes because of local and international conflicts. In the last two decades, a substantial increase in the number of displaced people has been recorded. We measured the social vulnerabilities of displaced populations using a mathematical approach in combination with application of geographical information systems (GIS) tools and techniques to visualise movement and draw attention to the location of significant concentration of vulnerabilities. A retrospective study approach based on datasets collected from governmental and non-governmental organisations working with refugees and internally displaced persons in Pakistan was used...
November 27, 2017: Geospatial Health
Hashem Shahroosvand, Mortaza Eskandari
This paper describes the implementation of robust and modular sensitizers containing aromatic-amphiphilic ligands to provide new insights into the relationship between the molecular structure and electron injection process governing the efficiency of dye-sensitized solar cells (DSSCs). The significance of this work lies in the combination of favorable experimental and theoretical results in a new class of Ru(ii) polypyridyl complexes with the molecular formula of [Ru(E101)(Dicnq)x(Y)] which is named M101-M104 when X = 1 and Y = bpy, X = 1 and Y = phen, X = 2, and X = 1 and Y = 2 NCS, respectively...
December 14, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Keith M Carroll, Armin W Knoll, Heiko Wolf, Urs Duerig
Surface assembly is often decomposed into two classes: reaction and diffusion limited processes. The transition between the two cases is complex because the dynamics for the two cases are so different. In this letter, we simulate, explain, and experimentally discuss the evolution of the spatial distribution for surface assemblies with diffusion limited and reaction limited processes. Explicitly, we demonstrate that diffusion limited processes and reaction limited process show some temporal differences, but more importantly, we show the spatial arrangement between the two scenarios are different enough to discriminate between the two cases...
December 14, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Hideaki Ueda, Michihiro Furusaka, Taeko Matsuura, Shusuke Hirayama, Kikuo Umegaki
In spot-scanning proton therapy, highly precise beam control is required in the treatment nozzle such that the proton beam does not spread out during transportation by restraining the divergence of the beam angle and spot size, simultaneously. In order to evaluate the beam-broadening behaviour induced by passing through the various nozzle components, we have developed a new method to calculate the angular divergence profile of a proton beam in the nozzle. The angular divergence of the proton beam for each nozzle component is calculated by the Monte Carlo simulation code, Geant4, assuming that the initial beam has no divergence...
December 13, 2017: Physics in Medicine and Biology
Jakub Kollar, Vladimir Frecer
During the last decades, the application of hybrid quantum mechanical/molecular mechanical (QM/MM) methods has been extended to the field of drug design. In principle, the approximate QM/MM approach offers a more complete description of drug-receptor non-covalent interactions. This is especially true when charge or proton transfer, chelation of metal ions or strong polarization of ligand and protein or surface chemical groups are involved. The aim of this work was to assess the accuracy of calculated non-covalent ligand-protein interaction energies ([Formula: see text]) obtained by the hybrid QM/MM approach employed in QSite/Jaguar of Schrödinger's Small-Molecule Drug Discovery Suite on a set of small-molecule model systems when compared to rigorous QM calculations...
December 12, 2017: Journal of Molecular Modeling
Jakub Škoda, Miroslav Pospíšil, Petr Kovář, Klára Melánová, Jan Svoboda, Ludvík Beneš, Vítězslav Zima
Classical molecular simulation methods were used for a detailed structural description of zirconium 4-sulfophenylphosphonate and zirconium phenylphosphonate 4-sulfophenylphosphonates with general formula Zr(HO3SC6H4PO3) x (C6H5PO3)2-x ·yH2O (x = 0.7-2; y = 0 or 2). First, models describing the structure of zirconium 4-sulfophenylphosphonate (x = 2) were calculated for the hydrated (y = 2) and dehydrated (y = 0) compounds. Subsequently, models for two mixed zirconium phenylphosphonate 4-sulfophenylphosphonates (x = 1...
December 12, 2017: Journal of Molecular Modeling
Lars Lind, Erik Ingelsson, Johan Sundström, Agneta Siegbahn, Erik Lampa
BACKGROUND: DNA methylation changes over life at specific sites in the genome, which can be used to estimate "biological age". The aim of this population-based longitudinal cohort study was to investigate the association between estimated biological age and incident cardiovascular disease (CVD). MATERIALS AND METHODS: Based on formulas published by Hannum et al and Horvath et al, "biological age" was calculated using data from the Illumina 450k Bead Methylation chip in 832 participants free from cardiovascular disease in the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (50% women, all aged 70 years at the examination)...
December 12, 2017: European Journal of Clinical Investigation
Moritz Kronlage, Véronique Schwehr, Daniel Schwarz, Tim Godel, Lorenz Uhlmann, Sabine Heiland, Martin Bendszus, Philipp Bäumer
OBJECTIVE: To identify demographic determinants of peripheral nerve diffusion tensor imaging (DTI) and to establish normal values for fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD). METHODS: Sixty subjects were examined at 3 Tesla by single-shot DTI. FA, AD, RD, and MD were collected for the sciatic, tibial, median, ulnar, and radial nerve and were correlated with demographic variables. RESULTS: Mean FA of all nerves declined with increasing age (r = -0...
December 11, 2017: European Radiology
Stefan Zimmermann, Dietrich Klusmann, Wolfgang Hampe
BACKGROUND: The validity of selection tests is underestimated if it is determined by simply calculating the predictor-outcome correlation found in the admitted group. This correlation is usually attenuated by two factors: (1) the combination of selection variables which can compensate for each other and (2) range restriction in predictor and outcome due to the absence of outcome measures for rejected applicants. METHODS: Here we demonstrate the logic of these artifacts in a situation typical for student selection tests and compare four different methods for their correction: two formulas for the correction of direct and indirect range restriction, expectation maximization algorithm (EM) and multiple imputation by chained equations (MICE)...
December 11, 2017: BMC Medical Education
Joanna J Ilska, Theo H E Meuwissen, Andreas Kranis, John A Woolliams
BACKGROUND: Molecular data is now commonly used to predict breeding values (BV). Various methods to calculate genomic relationship matrices (GRM) have been developed, with some studies proposing regression of coefficients back to the reference matrix of pedigree-based relationship coefficients (A). The objective was to compare the utility of two GRM: a matrix based on linkage analysis (LA) and anchored to the pedigree, i.e. [Formula: see text] and a matrix based on linkage disequilibrium (LD), i...
December 11, 2017: Genetics, Selection, Evolution: GSE
Bolanle Olubunmi Ibitoye, Bukunmi Michael Idowu, Akinwumi Babatunde Ogunrombi, Babalola Ishmael Afolabi
Purpose: The purpose of this study was to evaluate the correlations of ultrasonographically estimated volumes of pleural fluid with the actual effusion volume in order to determine the most reliable formula. Methods: In 32 consecutive patients with clinically diagnosed pleural effusion, an ultrasound estimation was made of the volume of effusion using four different formulae, including two in the erect position and two in the supine position. Closed-tube thoracostomy drainage using a 28-Fr chest tube was performed...
October 18, 2017: Ultrasonography
Yanling Yang, Chunxu Bai, Xiaoguang Xu, Yong Jiang
Using the transfer matrix method, the authors combine the analytical formula with numerical calculation to explore the shot noise and the conductance of massless Weyl fermions in the Weyl semimetal resonant junction. By varying the barrier strength, the structure of the junction, the Fermi energy and the crystallographic angle, the shot noise and the conductance can be tuned efficiently. For a quasiperiodic supperlattice, in complete contrast to the conventional junction case, the effect of the disorder strength on the shot noise and the conductance depends on the competition of the classical tunneling and the Klein tunneling...
December 11, 2017: Nanotechnology
Kristin Nistad, Frida Göransson, Eivind Støle, Hossein Shams, Björn Gjerdrum
PURPOSE: To determine whether use of a capsular tension ring (CTR) can increase refractive stability in patients with implantation of two different trifocal intraocular lenses (IOLs). METHODS: A prospective, consecutive series of eyes underwent refractive lens exchange with implantation of two different trifocal IOL designs: FineVision Micro F (non-toric) and FineVision POD FT (toric) (PhysIOL, Liege, Belgium). Power calculation was determined using the Haigis formula...
December 1, 2017: Journal of Refractive Surgery
Tiago B Ferreira, Paulo Ribeiro, Filomena J Ribeiro, João G O'Neill
PURPOSE: To compare the prediction error in the calculation of toric intraocular lenses (IOLs) associated with methods that estimate the power of the posterior corneal surface (ie, Barrett toric calculator and Abulafia-Koch formula) with that of methods that consider real measures obtained using Scheimpflug imaging: a software that uses vectorial calculation (Panacea toric calculator: and a ray tracing software (PhacoOptics, Aarhus Nord, Denmark)...
December 1, 2017: Journal of Refractive Surgery
Onur Kaypakli, Hasan Koca, Durmus Yıldıray Sahin, Fadime Karataş, Suleyman Ozbicer, Mevlüt Koç
AIM: The correct estimation of the VA origin as RVOT or LVOT results in reduced ablation duration reduced radiation exposure and decreased number of vascular access. In our study, we aimed to detect the predictive value of S-R difference in V1-V2 for differentiating the left from right ventricular outflow tract arrhythmias. METHODS: We included 123 patients with symptomatic frequent premature ventricular outflow tract contractions who underwent successful catheter ablation (70 male, 53 female; mean age 46...
December 10, 2017: Annals of Noninvasive Electrocardiology
Dawesh P Yadav, Saurabh Kedia, Kumble Seetharama Madhusudhan, Sawan Bopanna, Sandeep Goyal, Saransh Jain, Naval K Vikram, Raju Sharma, Govind K Makharia, Vineet Ahuja
Background: Results on body composition in Crohn's disease (CD) and ulcerative colitis (UC) have been heterogeneous and are lacking from Asia. Present study assessed body composition in CD/UC and correlated it with disease severity/duration. Methods: Patients of CD/UC following between Dec 2014 and Dec 2015 who consented for bioimpedance analysis for body fat measurement were included. Lean mass and fat-free mass index (FFMI) were calculated with standard formulae...
2017: Canadian Journal of Gastroenterology & Hepatology
Alexander A Shpak, Alla B Guekht, Tatiana A Druzhkova, Ksenia I Kozlova, Natalia V Gulyaeva
Purpose: To study the ciliary neurotrophic factor (CNTF) concentration in the aqueous humor (AH), lacrimal fluid (LF), and blood serum (BS) in patients with age-related cataract and primary open-angle glaucoma (POAG). Methods: CNTF concentrations were studied in 61 patients with age-related cataract, 55 patients with POAG combined with cataract, and 29 healthy controls (one eye in each person). Preliminary experiments permitted us to extend the minimum quantifiable value of the CNTF Quantikine enzyme-linked immunosorbent assay (ELISA) kit to 2...
2017: Molecular Vision
Eivind Aadland, Lars Bo Andersen, Turid Skrede, Ulf Ekelund, Sigmund Alfred Anderssen, Geir Kåre Resaland
INTRODUCTION: Knowledge of reproducibility of accelerometer-determined physical activity (PA) and sedentary time (SED) estimates are a prerequisite to conduct high-quality epidemiological studies. Yet, estimates of reproducibility might differ depending on the approach used to analyze the data. The aim of the present study was to determine the reproducibility of objectively measured PA and SED in children by directly comparing a day-by-day and a week-by-week approach to data collected over two weeks during two different seasons 3-4 months apart...
2017: PloS One
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