keyword
MENU ▼
Read by QxMD icon Read
search

Simulator

keyword
https://www.readbyqxmd.com/read/29786975/a-comparison-of-one-stage-vs-two-stage-individual-patient-data-meta-analysis-methods-a-simulation-study
#1
Evangelos Kontopantelis
BACKGROUND: Individual patient data (IPD) meta-analysis allows for the exploration of heterogeneity and can identify subgroups that most benefit from an intervention (or exposure), much more successfully than meta-analysis of aggregate data. One-stage or two-stage IPD meta-analysis is possible, with the former using mixed-effects regression models and the latter obtaining study-estimates through simpler regression models before aggregating using standard meta-analysis methodology. However, a comprehensive comparison of the two methods, in practice, is lacking...
May 22, 2018: Research Synthesis Methods
https://www.readbyqxmd.com/read/29786947/does-general-experience-affect-self-assessment
#2
Parisa Rezaiefar, Kelly Forse, Joseph K Burns, Sharon Johnston, Elizabeth Muggah, Claire Kendall, Douglas Archibald
BACKGROUND: The assessment of clinical competence is critical in medical education. Understanding the effect of general experience on a physician's self-assessment would help design more effective curricula and evaluations of procedural skills in postgraduate training and continuing professional development (CPD). In this observational study, we assessed the effect of general experience on the correlation between confidence and competence amongst experienced clinicians (ECs) and postgraduate trainees (PGTs) when learning an office-based procedure in pessary care...
May 22, 2018: Clinical Teacher
https://www.readbyqxmd.com/read/29786907/simulation-of-the-degradation-of-cyclic-ketene-acetal-and-vinyl-based-copolymers-synthesized-via-a-radical-process-influence-of-the-reactivity-ratios-on-the-degradability-properties
#3
Didier Gigmes, Paul H M Van Steenberge, Didier Siri, Dagmar R D'hooge, Yohann Guillaneuf, Catherine Lefay
The radical copolymerization of vinyl and cyclic ketene acetal (CKA) monomers is a promising way to prepare degradable vinyl polymers. The reactivity of the comonomer pair is known to be dependent of the vinyl monomer structure that requires to play with experimental conditions (feed ratio, overall monomer conversion, etc.) to target a desired cumulative (average) copolymer composition. Even if the materials are completely degradable, there is no information about the homogeneity of the degraded products. This theoretical study, using kinetic Monte Carlo simulations, allows simulating degradation at the molecular level...
May 22, 2018: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/29786862/experimental-fluence-modulated-proton-computed-tomography-by-pencil-beam-scanning
#4
George Dedes, Robert P Johnson, Mark Pankuch, Nick Detrich, Willemijn M A Pols, Simon Rit, Reinhard W Schulte, Katia Parodi, Guillaume Landry
PURPOSE: This experimental study is aimed at demonstrating, using a simple cylindrical water phantom, the feasibility of fluence modulated proton computed tomography (FMpCT) by pencil beam scanning (PBS) proton computed tomography (pCT). METHODS: The phase II pCT prototype of the Loma Linda U. and U. C. Santa Cruz was operated using the PBS beam line of the Northwestern Medicine Chicago Proton Center. A 20x10 grid of 1.37 cm full width half maximum pencil beams (PB) equally spaced by 1 cm was used to acquire 45 projections in step and shoot mode...
May 22, 2018: Medical Physics
https://www.readbyqxmd.com/read/29786861/temporally-feathered-intensity-modulated-radiation-therapy-a-planning-technique-to-reduce-normal-tissue-toxicity
#5
Juan Carlos López Alfonso, Shireen Parsai, Nikhil Joshi, Andrew Godley, Chirag Shah, Shlomo A Koyfman, Jimmy J Caudell, Clifton D Fuller, Heiko Enderling, Jacob G Scott
PURPOSE: Intensity modulated radiation therapy (IMRT) has allowed optimization of three-dimensional spatial radiation dose distributions permitting target coverage while reducing normal tissue toxicity. However, radiation-induced normal tissue toxicity is a major contributor to patients' quality of life and often a dose-limiting factor in the definitive treatment of cancer with radiation therapy. We propose the next logical step in the evolution of IMRT using canonical radiobiological principles, optimizing the temporal dimension through which radiation therapy is delivered to further reduce radiation-induced toxicity by increased time for normal tissue recovery...
May 22, 2018: Medical Physics
https://www.readbyqxmd.com/read/29786776/a-framework-for-image-based-modeling-of-acute-myocardial-ischemia-using-intramurally-recorded-extracellular-potentials
#6
Brett M Burton, Kedar K Aras, Wilson W Good, Jess D Tate, Brian Zenger, Rob S MacLeod
The biophysical basis for electrocardiographic evaluation of myocardial ischemia stems from the notion that ischemic tissues develop, with relative uniformity, along the endocardial aspects of the heart. These injured regions of subendocardial tissue give rise to intramural currents that lead to ST segment deflections within electrocardiogram (ECG) recordings. The concept of subendocardial ischemic regions is often used in clinical practice, providing a simple and intuitive description of ischemic injury; however, such a model grossly oversimplifies the presentation of ischemic disease-inadvertently leading to errors in ECG-based diagnoses...
May 21, 2018: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/29786774/computational-fluid-dynamics-modeling-of-the-human-pulmonary-arteries-with-experimental-validation
#7
Alifer D Bordones, Matthew Leroux, Vitaly O Kheyfets, Yu-An Wu, Chia-Yuan Chen, Ender A Finol
Pulmonary hypertension (PH) is a chronic progressive disease characterized by elevated pulmonary arterial pressure, caused by an increase in pulmonary arterial impedance. Computational fluid dynamics (CFD) can be used to identify metrics representative of the stage of PH disease. However, experimental validation of CFD models is often not pursued due to the geometric complexity of the model or uncertainties in the reproduction of the required flow conditions. The goal of this work is to validate experimentally a CFD model of a pulmonary artery phantom using a particle image velocimetry (PIV) technique...
May 21, 2018: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/29786739/synthesis-of-pure-silica-mfi-zeolites-using-imidazolium-based-long-dications-a-comparative-study-of-structure-directing-effects-derived-from-a-further-spacer-length-increase
#8
Peng Lu, Luis Gómez-Hortigüela, Miguel A Camblor
Length-dependent structure direction of linear methylimidazolium-based dications towards MFI zeolite, previously known only for the tetramethylene spacer, has also been found for octamethylene and decamethylene spacers. This works only under highly concentrated conditions, whereas dilution always tends to favor TON, a default structure that is the only zeolite obtained with the other reported dications (with tri-, penta-, and hexamethylene spacers). The locations and conformations of the dications have been studied by molecular mechanics simulations...
May 22, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29786724/influence-of-a-nanoparticle-on-the-structure-and-dynamics-of-model-ionomer-melts
#9
Janani Sampath, Lisa M Hall
We simulate a single spherical nanoparticle (NP) surrounded by partially neutralized ionomers. The coarse-grained ionomers consist of a linear backbone of neutral monomer beads with charged pendant beads and counterions, along with pendant 'sticker' beads that represent unneutralized acid groups. Two different NP interactions are considered; one in which the NP interacts uniformly with all beads in the system (neutral NP) and another in which the NP has higher cohesive interactions with ions and stickers (sticky NP)...
May 22, 2018: Soft Matter
https://www.readbyqxmd.com/read/29786720/a-strain-induced-subwavelength-structure-for-a-haze-free-and-highly-transparent-flexible-plastic-substrate
#10
Jae Yong Park, Juyoung Ham, Illhwan Lee, Jong-Lam Lee
This paper presents a method to produce subwavelength-scale (<250 nm) AgCl nanostructures on a flexible plastic film, which is indispensable for highly efficient flexible displays. Using Cl2 plasma treatment on an Ag-coated plastic film, AgCl nanostructures were produced through the reaction of Ag atoms with Cl radicals. During the reaction, the volume of AgCl expands, leading to drastically changed surface morphology from a two-dimensional (2D) flat Ag surface to a 3D subwavelength-scale AgCl nanostructure...
May 22, 2018: Nanoscale
https://www.readbyqxmd.com/read/29786716/unexpected-protonation-state-of-glu197-discovered-from-simulations-of-tacrine-in-butyrylcholinesterase
#11
Xiao Wan, Yuan Yao, Lei Fang, Junjun Liu
Butyrylcholinesterase (BChE) has been actively involved in drug discoveries from many fields for decades. In the crystal structure of the BChE-tacrine complex, there is an unanticipated formyl-proline molecule resolved very close to tacrine, raising an essential question on how reliable it is to apply the binding pose in a crystal structure to analyze related experimental observations, in which no formyl-proline is actually involved. In this study, by performing a series of 100 ns molecular dynamics simulations, we demonstrate that it is safe to employ the structural information from this crystal structure to analyze related experimental observations...
May 22, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29786669/protein-tyrosine-phosphatase-1b-inhibition-and-glucose-uptake-potentials-of-mulberrofuran-g-albanol-b-and-kuwanon-g-from-root-bark-of-morus-alba-l-in-insulin-resistant-hepg2-cells-an-in-vitro-and-in-silico-study
#12
Pradeep Paudel, Ting Yu, Su Hui Seong, Eun Bi Kuk, Hyun Ah Jung, Jae Sue Choi
Type II diabetes mellitus (T2DM) is the most common form of diabetes and has become a major health problem across the world. The root bark of Morus alba L. is widely used in Traditional Chinese Medicine for treatment and management of diabetes. The aim of the present study was to evaluate the enzyme inhibitory potentials of three principle components, mulberrofuran G ( 1 ), albanol B ( 2 ), and kuwanon G ( 3 ) in M. alba root bark against diabetes, establish their enzyme kinetics, carry out a molecular docking simulation, and demonstrate the glucose uptake activity in insulin-resistant HepG2 cells...
May 22, 2018: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29786663/modeling-the-effect-of-primary-and-secondary-twinning-on-texture-evolution-during-severe-plastic-deformation-of-a-twinning-induced-plasticity-steel
#13
Laszlo S Toth, Christian Haase, Robert Allen, Rimma Lapovok, Dmitri A Molodov, Mohammed Cherkaoui, Haitham El Kadiri
Modeling the effect of deformation twinning and the ensuing twin-twin- and slip-twin-induced hardening is a long-standing problem in computational mechanical metallurgy of materials that deform by both slip and twinning. In this work, we address this effect using the twin volume transfer method, which obviates the need of any cumbersome criterion for twin variant selection. Additionally, this method is capable of capturing, at the same time, secondary or double twinning, which is particularly important for modeling in large strain regimes...
May 22, 2018: Materials
https://www.readbyqxmd.com/read/29786642/determining-the-radiation-enhancement-effects-of-gold-nanoparticles-in-cells-in-a-combined-treatment-with-cisplatin-and-radiation-at-therapeutic-megavoltage-energies
#14
Celina Yang, Kyle Bromma, Wonmo Sung, Jan Schuemann, Devika Chithrani
Combined use of chemotherapy and radiation therapy is commonly used in cancer treatment, but the toxic effects on normal tissue are a major limitation. This study assesses the potential to improve radiation therapy when combining gold nanoparticle (GNP) mediated radiation sensitization with chemoradiation compared to chemoradiation alone. Incorporation of GNPs with 2 Gy, 6 MV (megavoltage) radiation resulted in a 19 ± 6% decrease in survival of MDA-MB-231 cells. Monte-Carlo simulations were performed to assess dosimetric differences in the presence of GNPs in radiation...
May 22, 2018: Cancers
https://www.readbyqxmd.com/read/29786641/photothermal-effectiveness-of-magnetite-nanoparticles-dependence-upon-particle-size-probed-by-experiment-and-simulation
#15
Robert J G Johnson, Jonathan D Schultz, Benjamin J Lear
The photothermal effect of nanoparticles has proven efficient for driving diverse physical and chemical processes; however, we know of no study addressing the dependence of efficacy on nanoparticle size. Herein, we report on the photothermal effect of three different sizes (5.5 nm, 10 nm and 15 nm in diameter) of magnetite nanoparticles (MNP) driving the decomposition of poly(propylene carbonate) (PPC). We find that the chemical effectiveness of the photothermal effect is positively correlated with particle volume...
May 22, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29786636/standard-reference-materials-for-cement-paste-part-ii-determination-of-mixing-ratios
#16
Dong Kyu Lee, Myoung Sung Choi
A variety of special concrete structures have been designed for domestic and overseas construction markets that require highly advanced construction technology. Therefore, it is necessary to secure quantitative construction technology and develop a standard reference material (hereinafter: SRM) with consistent flow performance and quality in order to evaluate the quantitative performance of flowability. On the other hand, the flowability of concrete is influenced greatly by the flowability of the cement paste...
May 22, 2018: Materials
https://www.readbyqxmd.com/read/29786613/biophysics-of-membrane-curvature-remodeling-at-molecular-and-mesoscopic-lengthscales
#17
Natesan Ramakrishnan, Ryan P Bradley, Richard W Tourdot, Ravi Radhakrishnan
At the micron scale, where cell organelles display an amazing complexity in their shape and organization, the physical properties of a biological membrane can be better-understood using continuum models subject to thermal (stochastic) undulations. Yet, the chief orchestrators of these complex and intriguing shapes are a specialized class of membrane associating often peripheral proteins called curvature remodeling proteins (CRPs) that operate at the molecular level through specific protein-lipid interactions...
May 22, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29786612/a-formalism-for-reference-dosimetry-in-photon-beams-in-the-presence-of-a-magnetic-field
#18
Bram van Asselen, Simon J Woodings, Sara L Hackett, Theo L van Soest, Jan G M Kok, Bas W Raaymakers, Jochem W H Wolthaus
A generic formalism is proposed for reference dosimetry in the presence of a magnetic field. Besides the regular correction factors from the conventional reference dosimetry formalisms, two factors are used to take into account magnetic field effects: 1) a dose conversion factor to correct for the change in local dose distribution and 2) a correction of the reading of the dosimeter used for the reference dosimetry measurements. The formalism was applied to the Elekta MRI-Linac, for which the 1.5 T magnetic field is orthogonal to the 7 MV photon beam...
May 22, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29786602/microfluidic-system-for-modelling-3d-tumour-invasion-into-surrounding-stroma-and-drug-screening
#19
Zhichang Du, Shengli Mi, Xiaoman Yi, Yuanyuan Xu, Wei Sun
Tumour invasion into the surrounding stroma is a critical step in metastasis, and it is necessary to clarify the role of microenvironmental factors in tumour invasion. We present a microfluidic system that simulated and controlled multi-factors of the tumour microenvironment for three-dimensional (3D) assessment of tumour invasion into the stroma. The simultaneous, precise and continuous arrangement of two 3D matrices was visualised to observe the migration of cancer cell populations or single cells by transfecting cells with a fluorescent protein...
May 22, 2018: Biofabrication
https://www.readbyqxmd.com/read/29786528/modelling-correlated-data-multilevel-models-and-generalized-estimating-equations-and-their-use-with-data-from-research-in-developmental-disabilities
#20
Dimitrios Vagenas, Vasiliki Totsika
BACKGROUND: The use of Multilevel Models (MLM) and Generalized Estimating Equations (GEE) for analysing clustered data in the field of intellectual and developmental disability (IDD) research is still limited. METHOD: We present some important features of MLMs and GEEs: main function, assumptions, model specification and estimators, sample size and power. We provide an overview of the ways MLMs and GEEs have been used in IDD research. RESULTS: While MLMs and GEEs are both appropriate for longitudinal and/or clustered data, they differ in the assumptions they impose on the data, and the inferences made...
May 18, 2018: Research in Developmental Disabilities
keyword
keyword
11734
1
2
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"