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https://www.readbyqxmd.com/read/29050161/-oblique-puncture-approach-via-anterolateral-to-c2-a-study-of-imaging-anatomy-on-corpses
#1
W H Yu, S C He, R J Du, H D Zhu, W Fang, S S Li, F H Sun
Objective: To determine the anatomical relation between the carotid artery or laryngopharynx and the needle path via anterolateral oblique approach to C2 vertebral body, and whether the simulated path can direct the actual procedure. Methods: Contrast agent was injected into bilateral carotid arteries of 10 fresh cadavers (20 sides), and then CT scans were performed on each subject. Bilateral simulated puncture paths were simulated on the image of two-dimensional reconstruction CT. The distance between the puncture site and middle line(AC), the angle between the simulated puncture paths and the median sagittal plane (AOB), the distance between the simulated puncture paths and the side wall of hypopharynx, or the carotid artery was measured respectively...
October 10, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/29049973/semi-analytical-representation-of-the-activation-level-in-stress-fibre-directions-as-alternative-to-the-angular-representation-in-the-bio-chemo-mechanical-model-for-cell-contractility
#2
Christian Rüdiger Bahls, Duy Truong, Ursula van Rienen
The bio-chemo-mechanical model has many applications in modelling cell contractility. In simulations this model usually is coupled to the continuum mechanics of the cell by defining a large number of directions for stress fibres at each point. In this paper, another representation for coupling the biochemical processes in the bio-chemo-mechanical model is introduced. Using a quadratic form to represent the angular dependency of the activation level, the model's number of degrees of freedom is significantly reduced...
October 10, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/29049962/evaluation-of-methods-for-managing-censored-results-when-calculating-the-geometric-mean
#3
Hannah G Mikkonen, Bradley O Clarke, Raghava Dasika, Christian J Wallis, Suzie M Reichman
Currently, there are conflicting views on the best statistical methods for managing censored environmental data. The method commonly applied by environmental science researchers and professionals is to substitute half the limit of reporting for derivation of summary statistics. This approach has been criticised by some researchers, raising questions around the interpretation of historical scientific data. This study evaluated four complete soil datasets, at three levels of simulated censorship, to test the accuracy of a range of censored data management methods for calculation of the geometric mean...
October 8, 2017: Chemosphere
https://www.readbyqxmd.com/read/29049946/rechargeable-flexible-and-mediator-free-biosupercapacitor-based-on-transparent-ito-nanoparticle-modified-electrodes-acting-in-%C3%A2%C2%B5m-glucose-containing-buffers
#4
Tim Bobrowski, Elena González Arribas, Roland Ludwig, Miguel D Toscano, Sergey Shleev, Wolfgang Schuhmann
We present a transparent and flexible self-charging biosupercapacitor based on an optimised mediator- and membrane-free enzymatic glucose/oxygen biofuel cell. Indium tin oxide (ITO) nanoparticles were spray-coated on transparent conducting ITO supports resulting in a flocculent, porous and nanostructured electrode surface. By this, high capacitive currents caused by an increased electrochemical double layer as well as enhanced catalytic currents due to a higher number of immobilised enzyme molecules were obtained...
October 11, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29049887/all-atom-molecular-dynamics-based-analysis-of-membrane-stabilizing-copolymer-interactions-with-lipid-bilayers-probed-under-constant-surface-tensions
#5
Evelyne M Houang, Frank S Bates, Yuk Yin Sham, Joseph M Metzger
An all-atom phospholipid bilayer and triblock copolymer model was developed for Molecular Dynamics (MD) studies. These were performed to investigate the mechanism of interaction between membrane stabilizing triblock copolymer P188 and 1-palmitoyl-2-oleoyl-sn- glycero-3-phosphatidylcholine (POPC) lipid bilayers under applied lateral surface tension (γ) to model membrane mechanical stress. Results showed that P188 insertion is driven by the hydrophobic polypropylene oxide (PPO) core and dependent on bilayer area per lipid...
October 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29049814/cost-effectiveness-of-testing-and-treatment-for-latent-tuberculosis-infection-in-residents-born-outside-the-united-states-with-and-without-medical-comorbidities-in-a-simulation-model
#6
Abriana Tasillo, Joshua A Salomon, Thomas A Trikalinos, C Robert Horsburgh, Suzanne M Marks, Benjamin P Linas
Importance: Testing for and treating latent tuberculosis infection (LTBI) is among the main strategies to achieve TB elimination in the United States. The best approach to testing among non-US born residents, particularly those with comorbid conditions, is uncertain. Objective: To estimate health outcomes, costs, and cost-effectiveness of LTBI testing and treatment among non-US born residents with and without medical comorbidities. Design, Setting, and Participants: Decision analytic tree and Markov cohort simulation model among non-US born residents with no comorbidities, with diabetes, with HIV infection, or with end-stage renal disease (ESRD) using a health care sector perspective with 3% annual discounting...
October 16, 2017: JAMA Internal Medicine
https://www.readbyqxmd.com/read/29049796/surgical-strategy-for-aortic-arch-reconstruction-after-the-norwood-procedure-based-on-numerical-flow-analysis
#7
Shohei Miyazaki, Kagami Miyaji, Keiichi Itatani, Norihiko Oka, Shinji Goto, Masanori Nakamura, Tadashi Kitamura, Tetsuya Horai, Koichi Sughimoto, Yuki Nakamura, Naoki Yoshimura
OBJECTIVES: Inefficient aortic flow after the Norwood procedure is known to lead to the deterioration of ventricular function due to an increased cardiac workload. To prevent the progression of aortic arch obstruction, arch reconstruction concomitant with second-stage surgery is recommended. The aim of this study was to determine the indications for reconstruction based on numerical simulation and to reveal the morphology that affects the haemodynamic parameters. METHODS: Fifteen patients who underwent the Norwood procedure or arch repair and Damus-Kaye-Stansel anastomosis were enrolled...
October 17, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/29049701/effects-of-blood-flow-dynamics-on-autologous-pericardial-degeneration-in-reconstructed-pulmonary-arteries
#8
Nobuyasu Kato, Masaaki Yamagishi, Keiichi Itatani, Takako Miyazaki, Yoshinobu Maeda, Satoshi Asada, Yoshiro Matsui, Hitoshi Yaku
OBJECTIVES: To clarify the risk factors for abnormal degeneration of autologous pericardium, the mechanical stress on the endothelial tissue caused by turbulent blood flow in the pulmonary artery (PA) reconstructed with autologous pericardium and major aortopulmonary collateral arteries was assumed in pulmonary atresia and ventricular septal defect. METHODS: Patient-specific PA models were created for 6 patients based on their past computed tomography images taken after unifocalization of major aortopulmonary collateral arteries...
October 12, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/29049689/a-nonlinear-viscoelastic-model-for-adipose-tissue-representing-tissue-response-at-a-wide-range-of-strain-rates-and-high-strain-levels
#9
Hosein Naseri, Håkan Johansson, Karin Brolin
Finite element human body models are nowdays commonly used to simulate pre- and in-crash occupant response in order to develop advanced safety systems. In this study a biofidelic model for adipose tissue is developed for this application. It is a nonlinear viscoelastic model based on the Reese et al. formulation. The model is formulated in a large strain framework and applied for finite element simulation of two types of experiments: rheological experiments and ramped-displacement experiments. The adipose tissue behavior in both experiments are represented well by this model...
October 16, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/29049602/speech-understanding-in-complex-listening-environments-by-listeners-fit-with-cochlear-implants
#10
Michael F Dorman, Rene H Gifford
Purpose: The aim of this article is to summarize recent published and unpublished research from our 2 laboratories on improving speech understanding in complex listening environments by listeners fit with cochlear implants (CIs). Method: CI listeners were tested in 2 listening environments. One was a simulation of a restaurant with multiple, diffuse noise sources, and the other was a cocktail party with 2 spatially separated point sources of competing speech. At issue was the value of the following sources of information, or interventions, on speech understanding: (a) visual information, (b) adaptive beamformer microphones and remote microphones, (c) bimodal fittings, that is, a CI and contralateral low-frequency acoustic hearing, (d) hearing preservation fittings, that is, a CI with preserved low-frequency acoustic in the same ear plus low-frequency acoustic hearing in the contralateral ear, and (e) bilateral CIs...
October 17, 2017: Journal of Speech, Language, and Hearing Research: JSLHR
https://www.readbyqxmd.com/read/29049565/a-low-cost-bioprosthetic-semilunar-valve-for-research-disease-modelling-and-surgical-training-applications
#11
Benoit Rosa, Zurab Machaidze, Borami Shin, Sunil Manjila, David W Brown, Christopher W Baird, John E Mayer, Pierre E Dupont
OBJECTIVES: This paper provides detailed instructions for constructing low-cost bioprosthetic semilunar valves for animal research and clinical training. This work fills an important gap between existing simulator training valves and clinical valves by providing fully functioning designs that can be employed in ex vivo and in vivo experiments and can also be modified to model valvular disease. METHODS: Valves are constructed in 4 steps consisting of creating a metal frame, covering it with fabric and attaching a suture ring and leaflets...
August 2, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/29049545/contributions-of-kinetic-energy-and-viscous-dissipation-to-airway-resistance-in-pulmonary-inspiratory-and-expiratory-airflows-in-multiscale-symmetric-airway-models-with-various-bifurcation-angles
#12
Sanghun Choi, Jiwoong Choi, Ching-Long Lin
The aim of this study was to investigate and quantify contributions of kinetic energy and viscous dissipation to airway resistance during inspiration and expiration at various flow-rates in airway models of different bifurcation angles. We employed symmetric airway models up to the 20th generation with the following five different bifurcation angles at a tracheal flow-rate of 20 L/min: 15, 25, 35, 45 and 55 degrees. Thus, a total of 10 CFD simulations for both inspiration and expiration were conducted. Furthermore, we performed an additional four simulations with tracheal flow-rate values of 10 and 40 L/min for a bifurcation angle of 35 degree to study the effect of flow-rate on inspiration and expiration...
October 10, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/29049538/3d-printed-mitral-valve-models-affordable-simulation-for-robotic-mitral-valve-repair
#13
Ned Premyodhin, Divneet Mandair, Alice S Ferng, Timothy S Leach, Ryan P Palsma, Mohammad Z Albanna, Zain I Khalpey
OBJECTIVES: 3D printed mitral valve (MV) models that capture the suture response of real tissue may be utilized as surgical training tools. Leveraging clinical imaging modalities, 3D computerized modelling and 3D printing technology to produce affordable models complements currently available virtual simulators and paves the way for patient- and pathology-specific preoperative rehearsal. METHODS: We used polyvinyl alcohol, a dissolvable thermoplastic, to 3D print moulds that were casted with liquid platinum-cure silicone yielding flexible, low-cost MV models capable of simulating valvular tissue...
July 31, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/29049515/simulating-reversibility-of-dcv-capture-in-en-passant-boutons-using-mathematical-modeling-to-understand-the-fate-of-dense-core-vesicles-in-en-passant-boutons
#14
Ivan A Kuznetsov, Andrey Kuznetsov
The goal of this paper is to use mathematical modeling to investigate the fate of dense core vesicles (DCVs) captured in en passant boutons located in nerve terminals. One possibility is that all DCVs captured in boutons are destroyed, another possibility is that captured DCVs can escape and reenter the pool of transiting DCVs that move through the boutons, and a third possibility is that some DCVs are destroyed in boutons, while some reenter the transiting pool. We developed a model by applying the conservation of DCVs in various compartments composing the terminal, to predict different scenarios that emerge from the above assumptions about the fate of DCVs captured in boutons...
October 16, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/29049474/virtual-surgery-for-the-nasal-airway-a-preliminary-report-on-decision-support-and-technology-acceptance
#15
Derek L Vanhille, Guilherme J M Garcia, Onur Asan, Azadeh A T Borojeni, Dennis O Frank-Ito, Julia S Kimbell, Sachin S Pawar, John S Rhee
Importance: Nasal airway obstruction (NAO) is a common problem that affects patient quality of life. Surgical success for NAO correction is variable. Virtual surgery planning via computational fluid dynamics (CFD) has the potential to improve the success rates of NAO surgery. Objective: To elicit surgeon feedback of a virtual surgery planning tool for NAO and to determine if this tool affects surgeon decision making. Design, Setting, and Participants: For this cross-sectional study, 60-minute face-to-face interviews with board-certified otolaryngologists were conducted at a single academic otolaryngology department from September 16, 2016, through October 7, 2016...
October 12, 2017: JAMA Facial Plastic Surgery
https://www.readbyqxmd.com/read/29049423/dynamic-water-patterns-change-the-stability-of-the-collapsed-filter-conformation-of-the-kcsa-k-channel
#16
Di Wu
The selectivity filter of the KcsA K+ channel has two typical conformations-the conductive and the collapsed conformations, respectively. The transition from the conductive to the collapsed filter conformation can represent the process of inactivation that depends on many environmental factors. Water molecules permeating behind the filter can influence the collapsed filter stability. Here we perform the molecular dynamics simulations to study the stability of the collapsed filter of the KcsA K+ channel under the different water patterns...
2017: PloS One
https://www.readbyqxmd.com/read/29049391/modelling-individual-tree-height-to-crown-base-of-norway-spruce-picea-abies-l-karst-and-european-beech-fagus-sylvatica-l
#17
Ram P Sharma, Zdeněk Vacek, Stanislav Vacek, Vilém Podrázský, Václav Jansa
Height to crown base (HCB) of a tree is an important variable often included as a predictor in various forest models that serve as the fundamental tools for decision-making in forestry. We developed spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total 19,404 trees of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) on the permanent sample plots that are located across the Czech Republic. Variables describing site quality, stand density or competition, and species mixing effects were included into the HCB model with use of dominant height (HDOM), basal area of trees larger in diameters than a subject tree (BAL- spatially inexplicit measure) or Hegyi's competition index (HCI-spatially explicit measure), and basal area proportion of a species of interest (BAPOR), respectively...
2017: PloS One
https://www.readbyqxmd.com/read/29049387/quantifying-the-strength-of-quorum-sensing-crosstalk-within-microbial-communities
#18
Kalinga Pavan T Silva, Prithiviraj Chellamuthu, James Q Boedicker
In multispecies microbial communities, the exchange of signals such as acyl-homoserine lactones (AHL) enables communication within and between species of Gram-negative bacteria. This process, commonly known as quorum sensing, aids in the regulation of genes crucial for the survival of species within heterogeneous populations of microbes. Although signal exchange was studied extensively in well-mixed environments, less is known about the consequences of crosstalk in spatially distributed mixtures of species...
October 19, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/29049343/a-sequential-monte-carlo-approach-to-gene-expression-deconvolution
#19
Oyetunji E Ogundijo, Xiaodong Wang
High-throughput gene expression data are often obtained from pure or complex (heterogeneous) biological samples. In the latter case, data obtained are a mixture of different cell types and the heterogeneity imposes some difficulties in the analysis of such data. In order to make conclusions on gene expresssion data obtained from heterogeneous samples, methods such as microdissection and flow cytometry have been employed to physically separate the constituting cell types. However, these manual approaches are time consuming when measuring the responses of multiple cell types simultaneously...
2017: PloS One
https://www.readbyqxmd.com/read/29049331/hiv-dynamics-linked-to-memory-cd4-t-cell-homeostasis
#20
John M Murray, John Zaunders, Sean Emery, David A Cooper, William J Hey-Nguyen, Kersten K Koelsch, Anthony D Kelleher
The dynamics of latent HIV is linked to infection and clearance of resting memory CD4+ T cells. Infection also resides within activated, non-dividing memory cells and can be impacted by antigen-driven and homeostatic proliferation despite suppressive antiretroviral therapy (ART). We investigated whether plasma viral level (pVL) and HIV DNA dynamics could be explained by HIV's impact on memory CD4+ T cell homeostasis. Median total, 2-LTR and integrated HIV DNA levels per μL of peripheral blood, for 8 primary (PHI) and 8 chronic HIV infected (CHI) individuals enrolled on a raltegravir (RAL) based regimen, exhibited greatest changes over the 1st year of ART...
2017: PloS One
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