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https://www.readbyqxmd.com/read/28445881/absence-of-decline-of-kidney-function-in-human-immunodeficiency-virus-infected-patients-under-routine-clinical-management
#1
Julie Boucquemont, Sylvie Lawson-Ayayi, Claire Rigothier, Fabrice Bonnet, Cécile Proust-Lima, Didier Neau, Carine Greib, Ghada Miremont-Salamé, François Dabis, Michel Dupon, Frédéric-Antoine Dauchy
BACKGROUND: Since the introduction of antiretroviral therapy (ART), human immunodeficiency virus (HIV)-infected patients have a drastically improved prognosis but at the same time they are also more affected by non-HIV related complications, such as chronic kidney disease. The objective of our study was to investigate the effect of proteinuria and tenofovir (TDF)-containing ART regimens on the temporal evolution of estimated glomerular filtration rate (eGFR). METHODS: Between April 2008 and October 2012, we enrolled 395 patients with a complete renal evaluation among patients from the ANRS C03 Aquitaine cohort, a prospective hospital-based cohort of HIV-1-infected patients under routine clinical management in southwestern France...
April 26, 2017: Nephron
https://www.readbyqxmd.com/read/28444503/comparative-evaluation-of-the-algorithms-for-parametric-mapping-of-the-novel-myocardial-pet-imaging-agent-18-f-fptp
#2
Ji Who Kim, Seongho Seo, Hyeon Sik Kim, Dong-Yeon Kim, Ho-Young Lee, Keon Wook Kang, Dong Soo Lee, Hee-Seung Bom, Jung-Joon Min, Jae Sung Lee
OBJECTIVE: ((18)F-fluoropentyl)triphenylphosphonium salt ((18)F-FPTP) is a new promising myocardial PET imaging tracer. It shows high accumulation in cardiomyocytes and rapid clearance from liver. We performed compartmental analysis of (18)F-FPTP PET images in rat and evaluated two linear analyses: linear least-squares (LLS) and a basis function method (BFM) for generating parametric images. The minimum dynamic scan duration for kinetic analysis was also investigated and computer simulation undertaken...
April 25, 2017: Annals of Nuclear Medicine
https://www.readbyqxmd.com/read/28444434/quantitative-anatomy-of-the-primary-ossification-center-of-the-femoral-shaft-in-human-fetuses
#3
Mariusz Baumgart, Marcin Wiśniewski, Magdalena Grzonkowska, Mateusz Badura, Bogdan Małkowski, Michał Szpinda
PURPOSE: Early clinical distinction of congenital defects in the femur is extremely important, as it determines the prognosis of the development of the lower limb. This study was performed to quantitatively examine the primary center of ossification in the femoral shaft with respect to its linear, planar, and volumetric parameters. MATERIALS AND METHODS: Using methods of CT, digital-image analysis, and statistics, the size of the primary ossification center of the femoral shaft in 47 spontaneously aborted human fetuses aged 17-30 weeks was studied...
April 25, 2017: Surgical and Radiologic Anatomy: SRA
https://www.readbyqxmd.com/read/28441880/a-three-dimensional-collagen-fiber-network-model-of-the-extracellular-matrix-for-the-simulation-of-the-mechanical-behaviors-and-micro-structures
#4
Shoubin Dong, Zetao Huang, Liqun Tang, Xiaoyang Zhang, Yongrou Zhang, Yi Jiang
The extracellular matrix (ECM) provides structural and biochemical support to cells and tissues, which is a critical factor for modulating cell dynamic behavior and intercellular communication. In order to further understand the mechanisms of the interactive relationship between cell and the ECM, we developed a three-dimensional (3D) collagen-fiber network model to simulate the micro structure and mechanical behaviors of the ECM and studied the stress-strain relationship as well as the deformation of the ECM under tension...
April 26, 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28440793/wavelength-dependent-plasmon-mediated-coalescence-of-two-gold-nanorods
#5
Jiunn-Woei Liaw, Wu-Chun Lin, Mao-Kuen Kuo
Plasmon-mediated coalescence of two nearby gold nanorods (NRs) suspended in water induced by the illumination of a linearly polarized (LP) light was studied theoretically. We analyzed the coupled optical forces and torques in terms of Maxwell's stress tensor upon two identical NRs irradiated by a LP plane wave using the multiple multipole method to estimate the optomechanical outcome. Numerical results show that the light-matter interaction can perform attraction or repulsion, depending on their initial configurations...
April 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28436840/a-parametric-computational-model-of-the-action-potential-of-pacemaker-cells
#6
Weiwei Ai, Nitish Patel, Partha Roop, Avinash Malik, Sidharta Andalam, Eugene Yip, Nathan Allen, Mark Trew
OBJECTIVE: A flexible, efficient and verifiable pacemaker cell model is essential to the design of real-time virtual hearts that can be used for closed-loop validation of cardiac devices. A new parametric model of pacemaker action potential is developed to address this need. METHODS: The action potential phases are modeled using hybrid automaton (HA) with one piecewise-linear continuous variable. The model can capture ratedependent dynamics, such as action potential duration (APD) restitution, conduction velocity (CV) restitution, and overdrive suppression by incorporating non-linear update functions...
April 24, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28436723/asymptomatic-peripheral-artery-disease-can-limit-maximal-exercise-capacity-in-chronic-obstructive-pulmonary-disease-patients-regardless-of-airflow-obstruction-and-lung-hyperinflation
#7
Ernesto Crisafulli, Chiara Scelfo, Panagiota Tzani, Marina Aiello, Giuseppina Bertorelli, Alfredo Chetta
Background Silent/asymptomatic peripheral artery disease may occur in patients with chronic obstructive pulmonary disease, but it is poorly investigated. The primary aim of this study was to evaluate in chronic obstructive pulmonary disease patients the impact of asymptomatic/silent peripheral artery disease on maximal exercise capacity; the secondary aim was to search for predictors of peripheral artery disease. Methods We prospectively enrolled chronic obstructive pulmonary disease outpatients. Data on anthropometric characteristics, lung function, cardiopulmonary exercise test and ankle-brachial index were recorded...
January 1, 2017: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/28434057/predictive-control-of-intersegmental-tarsal-movements-in-an-insect
#8
Alicia Costalago-Meruelo, David M Simpson, Sandor M Veres, Philip L Newland
In many animals intersegmental reflexes are important for postural and movement control but are still poorly undesrtood. Mathematical methods can be used to model the responses to stimulation, and thus go beyond a simple description of responses to specific inputs. Here we analyse an intersegmental reflex of the foot (tarsus) of the locust hind leg, which raises the tarsus when the tibia is flexed and depresses it when the tibia is extended. A novel method is described to measure and quantify the intersegmental responses of the tarsus to a stimulus to the femoro-tibial chordotonal organ...
April 22, 2017: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/28433346/biomechanical-flow-amplification-arising-from-the-variable-deformation-of-the-subglottic-mucosa
#9
Eric Goodyer, Frank Müller, Markus Hess, Karthikeyan Kandan, Farukh Farukh
OBJECTIVE: This study mapped the variation in tissue elasticity of the subglottic mucosa, applied these data to provide initial models of the likely deformation of the mucosa during the myoelastic cycle, and hypothesized as to the impact on the process of phonation. STUDY DESIGN: Six donor human larynges were dissected along the sagittal plane to expose the vocal folds and subglottic mucosa. A linear skin rheometer was used to apply a controlled shear force, and the resultant displacement was measured...
April 19, 2017: Journal of Voice: Official Journal of the Voice Foundation
https://www.readbyqxmd.com/read/28433177/kinetic-study-of-thermal-degradation-of-chitosan-as-a-function-of-deacetylation-degree
#10
M A Gámiz-González, D M Correia, S Lanceros-Mendez, V Sencadas, J L Gómez Ribelles, A Vidaurre
Thermal degradation of chitosan with varying deacetylation degree (DD) ranging between 50 and 85% was analyzed by dynamic thermogravimetric analysis at different heating rates. The present study focused on the temperature range between 500 and 800K, above water evaporation. Thermal degradation showed a main degradation stage in this temperature interval with a second stage that appeared in the weight derivative curves as a shoulder in the high temperature side of the main peak with increasing intensity as the DD decreased...
July 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28433026/variational-koopman-models-slow-collective-variables-and-molecular-kinetics-from-short-off-equilibrium-simulations
#11
Hao Wu, Feliks Nüske, Fabian Paul, Stefan Klus, Péter Koltai, Frank Noé
Markov state models (MSMs) and master equation models are popular approaches to approximate molecular kinetics, equilibria, metastable states, and reaction coordinates in terms of a state space discretization usually obtained by clustering. Recently, a powerful generalization of MSMs has been introduced, the variational approach conformation dynamics/molecular kinetics (VAC) and its special case the time-lagged independent component analysis (TICA), which allow us to approximate slow collective variables and molecular kinetics by linear combinations of smooth basis functions or order parameters...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28433019/tests-for-origins-of-and-corrections-to-non-gaussian-statistics-the-dipole-flip-model
#12
Addison J Schile, Ward H Thompson
Linear response approximations are central to our understanding and simulations of nonequilibrium statistical mechanics. Despite the success of these approaches in predicting nonequilibrium dynamics, open questions remain. Laird and Thompson [J. Chem. Phys. 126, 211104 (2007)] previously formalized, in the context of solvation dynamics, the connection between the static linear-response approximation and the assumption of Gaussian statistics. The Gaussian statistics perspective is useful in understanding why linear response approximations are still accurate for perturbations much larger than thermal energies...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28430270/atomistic-non-adiabatic-dynamics-of-the-lh2-complex-with-a-gpu-accelerated-ab-initio-exciton-model
#13
Aaron Sisto, Clem Stross, Marc W van der Kamp, Michael O'Connor, Simon McIntosh-Smith, Graham T Johnson, Edward G Hohenstein, Fred R Manby, David R Glowacki, Todd J Martinez
We recently outlined an efficient multi-tiered parallel ab initio excitonic framework that utilizes time dependent density functional theory (TDDFT) to calculate ground and excited state energies and gradients of large supramolecular complexes in atomistic detail - enabling us to undertake non-adiabatic simulations which explicitly account for the coupled anharmonic vibrational motion of all the constituent atoms in a supramolecular system. Here we apply that framework to the 27 coupled bacterio-chlorophyll-a chromophores which make up the LH2 complex, using it to compute an on-the-fly nonadiabatic surface-hopping (SH) trajectory of electronically excited LH2...
April 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28429996/are-athletes-doping-related-attitudes-predicted-by-their-perceptions-of-coaches-confrontation-efficacy
#14
Philip Sullivan, Parmida Razavi
BACKGROUND: The coaching process is complex and dynamic. Coaches are known to affect athlete attitudes indirectly, through athletes' perceptions and interpretations. This process has been verified with a variety of ethical behaviors. OBJECTIVES: The current study investigated the relationships between athletes' perceived doping confrontation efficacy of their coaches and athlete's anti-doping attitudes. METHODS: A sample of athletes (N = 96) completed a version of the Doping Confrontation Efficacy Scale that was modified to assess their perception of their coaches' anti-doping confrontation efficacy, and the PEAS (Performance Enhancing Attitude Scale), which assessed their performance-enhancing attitudes...
April 21, 2017: Substance Use & Misuse
https://www.readbyqxmd.com/read/28427818/a-necessary-condition-for-dispersal-driven-growth-of-populations-with-discrete-patch-dynamics
#15
Chris Guiver, David Packman, Stuart Townley
We revisit the question of when can dispersal-induced coupling between discrete sink populations cause overall population growth? Such a phenomenon is called dispersal driven growth and provides a simple explanation of how dispersal can allow populations to persist across discrete, spatially heterogeneous, environments even when individual patches are adverse or unfavourable. For two classes of mathematical models, one linear and one non-linear, we provide necessary conditions for dispersal driven growth in terms of the existence of a common linear Lyapunov function, which we describe...
April 17, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28426669/a-dynamic-genetic-hormonal-regulatory-network-model-explains-multiple-cellular-behaviors-of-the-root-apical-meristem-of-arabidopsis-thalian
#16
Mónica L García-Gómez, Eugenio Azpeitia, Elena R Álvarez-Buylla
The study of the concerted action of hormones and transcription factors is fundamental to understand cell differentiation and pattern formation during organ development. The root apical meristem of Arabidopsis thaliana is a useful model to address this. It has a stem cell niche near its tip conformed of a quiescent organizer and stem or initial cells around it, then a proliferation domain followed by a transition domain, where cells diminish division rate before transiting to the elongation zone; here, cells grow anisotropically prior to their final differentiation towards the plant base...
April 20, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28424868/non-invasive-measurements-of-the-dynamic-changes-in-the-ciliary-muscle-crystalline-lens-morphology-and-anterior-chamber-during-accommodation-with-a-high-resolution-oct
#17
José J Esteve-Taboada, Alberto Domínguez-Vicent, Daniel Monsálvez-Romín, Antonio J Del Águila-Carrasco, Robert Montés-Micó
PURPOSE: The purpose of the study was to assess non-invasively the changes in the anterior chamber eye, crystalline lens morphology, and ciliary muscle during accommodation by means of an anterior chamber optical coherence tomographer (OCT), and correlate them with vergence. METHODS: Twenty-five eyes of twenty-five healthy subjects, whose mean age was 29.9±7.1 years, were included and measured with an anterior chamber OCT. The central corneal thickness (CCT), anterior chamber depth (ACD), anterior crystalline lens radius of curvature (ALRC), crystalline lens thickness (CLT), and ciliary muscle area (CMA) were measured for each participant at 0, -1, -2, and -3 D of target vergence...
April 20, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/28423429/modeling-temperature-dependent-development-of-glyphodes-pyloalis-lepidoptera-pyralidae
#18
Zohreh Moallem, Azadeh Karimi-Malati, Ahad Sahragard, Arash Zibaee
Development of Glyphodes pyloalis Walker was studied under laboratory conditions at constant temperatures of 12, 16, 20, 24, 28, 30, 32, and 36 °C. No development occurred at 36 °C. Although eggs hatched at 12 ºC, no larvae were capable of developing to adult stage. At 16 ºC, survival rate was low (4%) and prepupal stage lasted 101.68 ± 11.03 d. Larvae completed development through six stadia at 16, 30, and 32 °C. Developmental time of overall immature stages varied from 46.62 d at 20 °C to 22...
January 1, 2017: Journal of Insect Science
https://www.readbyqxmd.com/read/28422954/identification-of-the-contribution-of-contact-and-aerial-biomechanical-parameters-in-acrobatic-performance
#19
Diane Haering, Aurore Huchez, Franck Barbier, Patrice Holvoët, Mickaël Begon
INTRODUCTION: Teaching acrobatic skills with a minimal amount of repetition is a major challenge for coaches. Biomechanical, statistical or computer simulation tools can help them identify the most determinant factors of performance. Release parameters, change in moment of inertia and segmental momentum transfers were identified in the prediction of acrobatics success. The purpose of the present study was to evaluate the relative contribution of these parameters in performance throughout expertise or optimisation based improvements...
2017: PloS One
https://www.readbyqxmd.com/read/28422648/fast-and-stable-signal-deconvolution-via-compressible-state-space-models
#20
Abbas Kazemipour, Ji Liu, Krystyna Solarana, Daniel Nagode, Patrick Kanold, Min Wu, Behtash Babadi
OBJECTIVE: Common biological measurements are in the form of noisy convolutions of signals of interest with possibly unknown and transient blurring kernels. Examples include EEG and calcium imaging data. Thus, signal deconvolution of these measurements is crucial in understanding the underlying biological processes. The objective of this paper is to develop fast and stable solutions for signal deconvolution from noisy, blurred and undersampled data, where the signals are in the form of discrete events distributed in time and space...
April 13, 2017: IEEE Transactions on Bio-medical Engineering
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