Read by QxMD icon Read

EM simulation

Monia Ranalli, Roberto Rocci
The literature on clustering for continuous data is rich and wide; differently, that one developed for categorical data is still limited. In some cases, the clustering problem is made more difficult by the presence of noise variables/dimensions that do not contain information about the clustering structure and could mask it. The aim of this paper is to propose a model for simultaneous clustering and dimensionality reduction of ordered categorical data able to detect the discriminative dimensions discarding the noise ones...
September 6, 2017: Psychometrika
Xuewen Fu, Bin Chen, Jau Tang, Ahmed H Zewail
Dynamics of active or propulsive Brownian particles in nonequilibrium status have recently attracted great interest in many fields including artificial micro/nanoscopic motors and biological entities. Understanding of their dynamics can provide insight into the statistical properties of physical and biological systems far from equilibrium. We report the translational dynamics of photon-activated gold nanoparticles (NPs) in water imaged by liquid-cell four-dimensional electron microscopy (4D-EM) with high spatiotemporal resolution...
August 2017: Science Advances
Don V Byars, Jordan Tozer, John M Joyce, Michael J Vitto, Lindsay Taylor, Turan Kayagil, Matt Jones, Matthew Bishop, Barry Knapp, David Evans
INTRODUCTION: Transesophageal echocardiography (TEE) is a well-established method of evaluating cardiac pathology. It has many advantages over transthoracic echocardiography (TTE), including the ability to image the heart during active cardiopulmonary resuscitation. This prospective simulation study aims to evaluate the ability of emergency medicine (EM) residents to learn TEE image acquisition techniques and demonstrate those techniques to identify common pathologic causes of cardiac arrest...
August 2017: Western Journal of Emergency Medicine
Kenneth H Downing, Robert M Glaeser
The extent to which the resolution varies within a three-dimensional (3-D) reconstruction, when the diameter of an object is large, is investigated computationally. Numerical simulation is used to model ideal three-dimensional point-spread functions at different radial positions within an object. It is shown that reconstructed density maps are affected less than might have been expected when particles are larger than the depth of field. This favorable outcome is attributed mainly to the fact that a point which lies outside the depth of field relative to the center, for some orientations of the object, will also lie within the depth of field for other orientations...
August 19, 2017: Ultramicroscopy
Markus A Seeger
Structural biology has advanced our understanding of membrane proteins like no other scientific discipline in the past two decades and the number of high resolution membrane transporter structures solved by X-ray crystallography has increased exponentially over this time period. Currently, single particle cryo-EM is in full swing due to a recent resolution revolution and permits for structural insights of proteins that were refractory to crystallization. It is foreseeable that multiple structures of many human transporters will be solved in the coming five years...
August 31, 2017: Biochimica et Biophysica Acta
Weifeng Wang, Nigel T Roulet, Youngil Kim, Ian B Strachan, Paul Del Giorgio, Yves T Prairie, Alain Tremblay
To quantify CO2 emissions from water surface of a reservoir that was shaped by flooding the boreal landscape, we developed a daily time-step reservoir biogeochemistry model. We calibrated the model using the measured concentrations of dissolved organic and inorganic carbon (C) in a young boreal hydroelectric reservoir, Eastmain-1 (EM-1), in northern Quebec, Canada. We validated the model against observed CO2 fluxes from an eddy covariance tower in the middle of EM-1. The model predicted the variability of CO2 emissions reasonably well compared to the observations (root mean square error: 0...
August 29, 2017: Science of the Total Environment
Jaeun Choi, Donglin Zeng, Andrew F Olshan, Jianwen Cai
Joint models with shared Gaussian random effects have been conventionally used in analysis of longitudinal outcome and survival endpoint in biomedical or public health research. However, misspecifying the normality assumption of random effects can lead to serious bias in parameter estimation and future prediction. In this paper, we study joint models of general longitudinal outcomes and survival endpoint but allow the underlying distribution of shared random effect to be completely unknown. For inference, we propose to use a mixture of Gaussian distributions as an approximation to this unknown distribution and adopt an Expectation-Maximization (EM) algorithm for computation...
August 30, 2017: Lifetime Data Analysis
Mengfei Li, Christian Hansen, Georg Rose
PURPOSE: To assess the accuracy of medical electromagnetic tracking systems, reference positioning systems are generally required. Errors are unavoidable in such systems, and despite how tiny they may be, prevent the ground truth from being known. In this work, a simulator was developed and used to analyze the theoretical system performances in electromagnetic tracking. METHODS: To simulate the entire tracking process, the magnetic dipole model, Faraday's law, and a mathematical optimization algorithm are applied...
August 29, 2017: International Journal of Computer Assisted Radiology and Surgery
N Nizam-Uddin, Ibrahim Elshafiey
This paper proposes a hybrid hyperthermia treatment system, utilizing two noninvasive modalities for treating brain tumors. The proposed system depends on focusing electromagnetic (EM) and ultrasound (US) energies. The EM hyperthermia subsystem enhances energy localization by incorporating a multichannel wideband setting and coherent-phased-array technique. A genetic algorithm based optimization tool is developed to enhance the specific absorption rate (SAR) distribution by reducing hotspots and maximizing energy deposition at tumor regions...
2017: BioMed Research International
Danielle Hart, William Bond, Jeffery Siegelman, Daniel Miller, Michael Cassara, Lisa Barker, Shilo Anders, James Ahn, Hubert Huang, Christopher Strother, Joshua Hui
INTRODUCTION: All residency programs in the United States are required to report their residents' progress on the Milestones to the Accreditation Council for Graduate Medical Education (ACGME) biannually. Since the development and institution of this competency-based assessment framework, residency programs have been attempting to ascertain the best ways to assess resident performance on these metrics. Simulation was recommended by the ACGME as one method of assessment for many of the milestone subcompetencies...
August 20, 2017: Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine
Andrew Grock, Adam R Aluisio, Elizabeth Abram, Patricia Roblin, Bonnie Arquilla
OBJECTIVE: Disasters by definition overwhelm the resources of a hospital and may require a response from a range of practitioners. Disaster training is part of emergency medicine (EM) resident curricula, but less emphasized in other training programs. This study aimed to compare disaster educational training and confidence levels among resident trainees from multiple specialties. DESIGN: A structured questionnaire assessed graduate medical training in disaster education and self-perceived confidence in disaster situations...
January 2017: American Journal of Disaster Medicine
Xiaona Sheng, Yihong Qiu, Ying Zhou, Wensheng Zhu
With the rapid development of statistical genetics, the deep researches of ordinal traits have been gradually emphasized. The data of these traits bear relatively less information than those of continuous phenotypes, therefore it is more complex to map the quantitative trait loci (QTL) of ordinal traits. In this paper, the multiple-interval mapping method is considered in the genetic mapping of ordinal traits. By combining threshold model and statistical model, we build a cumulative logistic regression model to express the relationship between the ordinal data and the QTL genotypes...
November 7, 2017: Journal of Theoretical Biology
Joseph V Rispoli, Steven M Wright, Craig R Malloy, Mary P McDougall
BACKGROUND: Human voxel models incorporating detailed anatomical features are vital tools for the computational evaluation of electromagnetic (EM) fields within the body. Besides whole-body human voxel models, phantoms representing smaller heterogeneous anatomical features are often employed; for example, localized breast voxel models incorporating fatty and fibroglandular tissues have been developed for a variety of EM applications including mammography simulation and dosimetry, magnetic resonance imaging (MRI), and ultra-wideband microwave imaging...
2017: Journal of Biomedical Graphics and Computing
Elaine Cristina Negri, Alessandra Mazzo, José Carlos Amado Martins, Gerson Alves Pereira, Rodrigo Guimarães Dos Santos Almeida, César Eduardo Pedersoli
Objective: to identify in the literature the gains health students and professionals perceive when using clinical simulation with dramatization resources. Method: integrative literature review, using the method proposed by the Joanna Briggs Institute (JBI). A search was undertaken in the following databases: Latin American and Caribbean Health Sciences Literature, Web of Science, National Library of Medicine, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Scopus, Scientific Electronic Library Online...
August 3, 2017: Revista Latino-americana de Enfermagem
(no author information available yet)
[This corrects the article doi: 10.5935/abc.20170080].
July 2017: Arquivos Brasileiros de Cardiologia
Hedvig Tordai, Ibolya Leveles, Tamás Hegedűs
Cystic fibrosis (CF), a lethal monogenic disease, is caused by mutant variants of the CF transmembrane conductance regulator (CFTR). Recent advances in single molecule cryo-EM methods enabled structural determination of full-length human and zebrafish CFTR, achieving an important milestone for CF drug development. To relate these structures to the gating cycle, we examined its dynamic features using molecular dynamics simulations. Our results show that the nucleotide binding domains (NBDs) in this bottom-open apo conformation exhibit motions related to dimerization and the bottom-closed apo CFTR model indicates opening of NBDs in contrast to transporters...
July 31, 2017: Biochemical and Biophysical Research Communications
Wenting Li, Zhengwu Jiang, Zhenghong Yang
The breakage of capsules upon crack propagation is crucial for achieving crack healing in encapsulation-based self-healing materials. A mesomechanical model was developed in this study to simulate the process of crack propagation in a matrix and the potential of debonding. The model used the extended finite element method (XFEM) combined with a cohesive zone model (CZM) in a two-dimensional (2D) configuration. The configuration consisted of an infinite matrix with an embedded crack and a capsule nearby, all subjected to a uniaxial remote tensile load...
May 27, 2017: Materials
Martin Schoen, Andrew J Haslam, George Jackson
The phase behavior and structure of a simple square-well bulk fluid with anisotropic interactions is described in detail. The orientation dependence of the intermolecular interactions allows for the formation of a nematic liquid-crystalline phase in addition to the more conventional isotropic gas and liquid phases. A version of classical density functional theory (DFT) is employed to determine the properties of the model, and comparisons are made with the corresponding data from Monte Carlo (MC) computer simulations in both the grand canonical and canonical ensembles, providing a benchmark to assess the adequacy of the DFT results...
September 5, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Ling Chen, Benjamin M W Tsui, Greta S P Mok
OBJECTIVE: SPECT is a powerful tool for diagnosing or staging brain diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) but is limited by its inferior resolution and sensitivity. At the same time, pinhole SPECT provides superior resolution and detection efficiency trade-off as compared to the conventional parallel-hole collimator for imaging small field-of-view (FOV), which fits for the case of brain imaging. In this study, we propose to develop and evaluate two multi-pinhole (MPH) collimator designs to improve the imaging of cerebral blood flow and striatum...
July 28, 2017: Annals of Nuclear Medicine
Hung-Yu Chang, Xuejin Li, George Em Karniadakis
Erythrocytes in patients with type-2 diabetes mellitus (T2DM) are associated with reduced cell deformability and elevated blood viscosity, which contribute to impaired blood flow and other pathophysiological aspects of diabetes-related vascular complications. In this study, by using a two-component red blood cell (RBC) model and systematic parameter variation, we perform detailed computational simulations to probe the alteration of the biomechanical, rheological, and dynamic behavior of T2DM RBCs in response to morphological change and membrane stiffening...
July 25, 2017: Biophysical Journal
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"