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https://www.readbyqxmd.com/read/28934833/hemodynamic-analysis-of-radiation-induced-damage-in-common-carotid-arteries-by-using-color-doppler-ultrasonography
#1
Alireza Mohammadkarim, Manijhe Mokhtari-Dizaji, Ali Kazemian, Hazhir Saberi
Purpose: The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography. Methods: We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid blood flow and arterial diameter changes, color Doppler ultrasonography parameters such as peak systolic velocity, end diastolic velocity, mean velocity, systolic-to-diastolic velocity (S/D) ratio, pulsatility index (PI), resistive index (RI), and instantaneous diameter changes were evaluated before and after external radiotherapy...
April 14, 2017: Ultrasonography
https://www.readbyqxmd.com/read/28934629/lacking-linearity-in-quantitative-stable-isotope-lc-ms-ms-measurement-of-f2-isoprostanes-is-an-irrefutable-indicator-of-analytical-inadequacy
#2
Dimitrios Tsikas, Erik Hanff
In LC-MS/MS-basedquantitative analysis of biological substances such as the F2-isoprostanes including 8-iso-prostaglandin F2α (i.e., 8-iso-PGF2α) use of stable-isotope labelled analogues at matrix-relevant concentrations is indispensable, enables linearity in relevant concentration ranges, and minimizes matrix effects. The quality of the linearity of calibration curves is an indicator of the analytical reliability of the LC-MS/MS method. Poor linearity is a convincing evidence of lacking analytical reliability...
September 8, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28934594/noncoding-rnas-in-polycomb-and-trithorax-regulation-a-quantitative-perspective
#3
Leonie Ringrose
The question of how noncoding RNAs are involved in Polycomb group (PcG) and Trithorax group (TrxG) regulation has been on an extraordinary journey over the last three decades. Favored models have risen and fallen, and healthy debates have swept back and forth. The field has recently reached a critical mass of compelling data that throws light on several previously unresolved issues. The time is ripe for a fruitful combination of these findings with two other long-running avenues of research, namely the biochemical properties of the PcG/TrxG system and the application of theoretical mathematical models toward an understanding of the system's regulatory properties...
September 15, 2017: Annual Review of Genetics
https://www.readbyqxmd.com/read/28934370/the-risk-of-sustained-sexual-transmission-of-zika-is-underestimated
#4
Antoine Allard, Benjamin M Althouse, Laurent Hébert-Dufresne, Samuel V Scarpino
Pathogens often follow more than one transmission route during outbreaks-from needle sharing plus sexual transmission of HIV to small droplet aerosol plus fomite transmission of influenza. Thus, controlling an infectious disease outbreak often requires characterizing the risk associated with multiple mechanisms of transmission. For example, during the Ebola virus outbreak in West Africa, weighing the relative importance of funeral versus health care worker transmission was essential to stopping disease spread...
September 21, 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28934210/oncolytic-potency-and-reduced-virus-tumor-specificity-in-oncolytic-virotherapy-a-mathematical-modelling-approach
#5
Khaphetsi Joseph Mahasa, Amina Eladdadi, Lisette de Pillis, Rachid Ouifki
In the present paper, we address by means of mathematical modeling the following main question: How can oncolytic virus infection of some normal cells in the vicinity of tumor cells enhance oncolytic virotherapy? We formulate a mathematical model describing the interactions between the oncolytic virus, the tumor cells, the normal cells, and the antitumoral and antiviral immune responses. The model consists of a system of delay differential equations with one (discrete) delay. We derive the model's basic reproductive number within tumor and normal cell populations and use their ratio as a metric for virus tumor-specificity...
2017: PloS One
https://www.readbyqxmd.com/read/28934157/complete-systematic-error-model-of-ssr-for-sensor-registration-in-atc-surveillance-networks
#6
Ángel J Jarama, Jaime López-Araquistain, Gonzalo de Miguel, Juan A Besada
In this paper, a complete and rigorous mathematical model for secondary surveillance radar systematic errors (biases) is developed. The model takes into account the physical effects systematically affecting the measurement processes. The azimuth biases are calculated from the physical error of the antenna calibration and the errors of the angle determination dispositive. Distance bias is calculated from the delay of the signal produced by the refractivity index of the atmosphere, and from clock errors, while the altitude bias is calculated taking into account the atmosphere conditions (pressure and temperature)...
September 21, 2017: Sensors
https://www.readbyqxmd.com/read/28934102/pose-estimation-of-a-mobile-robot-based-on-fusion-of-imu-data-and-vision-data-using-an-extended-kalman-filter
#7
Mary B Alatise, Gerhard P Hancke
Using a single sensor to determine the pose estimation of a device cannot give accurate results. This paper presents a fusion of an inertial sensor of six degrees of freedom (6-DoF) which comprises the 3-axis of an accelerometer and the 3-axis of a gyroscope, and a vision to determine a low-cost and accurate position for an autonomous mobile robot. For vision, a monocular vision-based object detection algorithm speeded-up robust feature (SURF) and random sample consensus (RANSAC) algorithms were integrated and used to recognize a sample object in several images taken...
September 21, 2017: Sensors
https://www.readbyqxmd.com/read/28934013/reconciling-conflicting-models-for-global-control-of-cell-cycle-transcription
#8
Chun-Yi Cho, Francis C Motta, Christina M Kelliher, Anastasia Deckard, Steven B Haase
Models for the control of global cell-cycle transcription have advanced from a CDK-APC/C oscillator, a transcription factor (TF) network, to coupled CDK-APC/C and TF networks. Nonetheless, current models were challenged by a recent study that concluded that the cell-cycle transcriptional program is primarily controlled by a CDK-APC/C oscillator in budding yeast. Here we report an analysis of the transcriptome dynamics in cyclin mutant cells that were not queried in the previous study. We find that B-cyclin oscillation is not essential for control of phase-specific transcription...
September 21, 2017: Cell Cycle
https://www.readbyqxmd.com/read/28933344/first-outbreak-of-zika-virus-in-the-continental-united-states-a-modelling-analysis
#9
Giovanni Marini, Giorgio Guzzetta, Roberto Rosà, Stefano Merler
Since 2015, Zika virus (ZIKV) has spread throughout Latin and Central America. This emerging infectious disease has been causing considerable public health concern because of severe neurological complications, especially in newborns after congenital infections. In July 2016, the first outbreak in the continental United States was identified in the Wynwood neighbourhood of Miami-Dade County, Florida. In this work, we investigated transmission dynamics using a mathematical model calibrated to observed data on mosquito abundance and symptomatic human infections...
September 14, 2017: Euro Surveillance: Bulletin Européen sur les Maladies Transmissibles, European Communicable Disease Bulletin
https://www.readbyqxmd.com/read/28933262/the-measurement-and-mathematical-analysis-of-5-fu-release-from-magnetic-polymeric-nanocapsules-following-the-application-of-ultrasound
#10
Ziaeddin Abed, Samideh Khoei, Behafarid Ghalandari, Jaber Beik, Ali Shakeri-Zadeh, Habib Ghaznavi, Mohammad Bagher Shiran
OBJECTIVE: To study the effects of ultrasound irradiation on the release profile of 5-fluorouracil (5-Fu) loaded magnetic poly lactic co-glycolic acid (PLGA) nanocapsules. Also, the controlled drug-release behaviour of the nanocapsules was mathematically investigated. METHOD: The nanocapsules were synthesized, dispersed in phosphate buffered saline (PBS), transferred to a dialysis bag, and finally, irradiated by various ultrasound parameters (1 or 3MHz; 0.3-1W/cm2; 5-10 minutes)...
September 21, 2017: Anti-cancer Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/28932848/exploration-of-significant-influences-of-the-operating-conditions-on-the-local-o2-transport-in-proton-exchange-membrane-fuel-cells-pemfcs
#11
Shuiyun Shen, Xiaojing Cheng, Chao Wang, Xiaohui Yan, Changchun Ke, Jiewei Yin, Junliang Zhang
A drastic reduction of the Pt loading in the cathode catalyst layers (CCLs) of proton exchange membrane fuel cells (PEMFCs) is much desired. However, a decrease in Pt loading inevitably leads to an unexpected increase of local O2 transport resistance (rLocal) and severely weakens the fuel cell performance, particularly at high current densities. Thus, it is both urgent and meaningful to explore the impacts of the operating conditions on rLocal in CCLs and therefore to clarify the intrinsic mechanism. Herein, we systematically explore the influences of the operating conditions, in terms of the dry O2 mole fraction, the relative humidity, the operating pressure and the temperature on rLocal using limiting current measurements combined with mathematical calculations...
September 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28932674/propulsion-and-chemotaxis-in-bacteria-driven-microswimmers
#12
Jiang Zhuang, Byung-Wook Park, Metin Sitti
Despite the large body of experimental work recently on biohybrid microsystems, few studies have focused on theoretical modeling of such systems, which is essential to understand their underlying functioning mechanisms and hence design them optimally for a given application task. Therefore, this study focuses on developing a mathematical model to describe the 3D motion and chemotaxis of a type of widely studied biohybrid microswimmer, where spherical microbeads are driven by multiple attached bacteria. The model is developed based on the biophysical observations of the experimental system and is validated by comparing the model simulation with experimental 3D swimming trajectories and other motility characteristics, including mean squared displacement, speed, diffusivity, and turn angle...
September 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://www.readbyqxmd.com/read/28932190/empirical-evaluation-of-voluntarily-activatable-muscle-synergies
#13
Shunta Togo, Hiroshi Imamizu
The muscle synergy hypothesis assumes that individual muscle synergies are independent of each other and voluntarily controllable. However, this assumption has not been empirically tested. This study tested if human subjects can voluntarily activate individual muscle synergies extracted by non-negative matrix factorization (NMF), the standard mathematical method for synergy extraction. We defined the activation of a single muscle synergy as the generation of a muscle activity pattern vector parallel to the single muscle synergy vector...
2017: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/28932145/comparison-of-using-different-bridge-prosthetic-designs-for-partial-defect-restoration-through-mathematical-modeling
#14
Oksana Styranivska, Nataliia Kliuchkovska, Nataliya Mykyyevych
OBJECTIVE: To analyze the stress-strain states of bone and abutment teeth during the use of different prosthetic designs of fixed partial dentures with the use of relevant mathematical modeling principles. MATERIALS AND METHODS: The use of Comsol Multiphysics 3.5 (Comsol AB, Sweden) software during the mathematical modeling of stress-strain states provided numerical data for analytical interpretation in three different clinical scenarios with fixed dentures and different abutment teeth and demountable prosthetic denture with the saddle-shaped intermediate part...
July 2017: European Journal of Dentistry
https://www.readbyqxmd.com/read/28932097/an-extended-inequality-approach-for-evaluating-decision-making-units-with-a-single-output
#15
Xiao-Li Meng, Fu-Gui Shi
In this work, an extended evaluation approach for decision making units (DMUs) with a single output is proposed. Firstly, the input and output data for each DMU are changed in the same proportion until all the outputs are equal, and then the coordinate system is established with input i as the ith coordinate axis. Secondly, in the coordinate system, the production possibility set, which is spanned by all the DMUs without the evaluated DMU, is expressed by inequalities. Moreover, the mathematical expression of the line segment joining the origin to the evaluated DMU is given...
2017: Journal of Inequalities and Applications
https://www.readbyqxmd.com/read/28931863/thp-1-derived-macrophages-render-lung-epithelial-cells-hypo-responsive-to-legionella-pneumophila-a-systems-biology-study
#16
Christine Schulz, Xin Lai, Wilhelm Bertrams, Anna Lena Jung, Alexandra Sittka-Stark, Christina Elena Herkt, Harshavadhan Janga, Katja Zscheppang, Christina Stielow, Leon Schulte, Stefan Hippenstiel, Julio Vera, Bernd Schmeck
Immune response in the lung has to protect the huge alveolar surface against pathogens while securing the delicate lung structure. Macrophages and alveolar epithelial cells constitute the first line of defense and together orchestrate the initial steps of host defense. In this study, we analysed the influence of macrophages on type II alveolar epithelial cells during Legionella pneumophila-infection by a systems biology approach combining experimental work and mathematical modelling. We found that L. pneumophila-infected THP-1-derived macrophages provoke a pro-inflammatory activation of neighboring lung epithelial cells, but in addition render them hypo-responsive to direct infection with the same pathogen...
September 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28931634/improved-prediction-accuracy-for-disease-risk-mapping-using-gaussian-process-stacked-generalization
#17
Samir Bhatt, Ewan Cameron, Seth R Flaxman, Daniel J Weiss, David L Smith, Peter W Gething
Maps of infectious disease-charting spatial variations in the force of infection, degree of endemicity and the burden on human health-provide an essential evidence base to support planning towards global health targets. Contemporary disease mapping efforts have embraced statistical modelling approaches to properly acknowledge uncertainties in both the available measurements and their spatial interpolation. The most common such approach is Gaussian process regression, a mathematical framework composed of two components: a mean function harnessing the predictive power of multiple independent variables, and a covariance function yielding spatio-temporal shrinkage against residual variation from the mean...
September 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28931601/local-cellular-neighbourhood-controls-proliferation-in-cell-competition
#18
Anna Bove, Daniel Gradeci, Yasuyuki Fujita, Shiladitya Banerjee, Guillaume Charras, Alan R Lowe
Cell competition is a quality control mechanism through which tissues eliminate unfit cells. Cell competition can result from short-range biochemical inductions or long-range mechanical cues. However, little is known about how cell-scale interactions give rise to population shifts in tissues, due to the lack of experimental and computational tools to efficiently characterise interactions at the single-cell level. Here, we address these challenges by combining long-term automated microscopy with deep learning image analysis to decipher how single-cell behaviour determines tissue make-up during competition...
September 20, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/28931382/using-peer-review-to-distribute-group-work-marks-equitably-between-medical-students
#19
Alex R Cook, Mikael Hartman, Nan Luo, Judy Sng, Ngan Phoon Fong, Wei Yen Lim, Mark I-Cheng Chen, Mee Lian Wong, Natarajan Rajaraman, Jeannette Jen-Mai Lee, Gerald Choon-Huat Koh
BACKGROUND: Although peer assessment has been used for evaluating performance of medical students and practicing doctors, it has not been studied as a method to distribute a common group work mark equitably to medical students working in large groups where tutors cannot observe all students constantly. METHODS: The authors developed and evaluated a mathematical formulation whereby a common group mark could be distributed among group members using peer assessment of individual contributions to group work, maintaining inter-group variation in group work scores...
September 20, 2017: BMC Medical Education
https://www.readbyqxmd.com/read/28931297/-intracranial-pressure-evaluation-by-ophthalmologist
#20
J Čmelo, R Illéš, J Šteňo
The value of ICT is important in diagnosis of the diseases of the eye and orbit Methods for direct measurement of intracranial pressure (ICT) are exact, but they are invasive and there is some risk of infection and damage of the tissue. Currently there are 2 valid indirect methods of mesurement of IKT. Digital Ophthalmodynamometry (D-ODM) and Transcranial Doppler ultrasonography (TDU). D-ODM is a non-invasive method for measuring of the Pulsating Venous Pressure (VPT). We can measure VPT by the pulse phenomena...
2017: Ceská a Slovenská Oftalmologie
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