Read by QxMD icon Read

Cell simulation

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
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
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
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
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
Hyeonji Hong, Eunseop Yeom, Ho Seong Ji, Hyun Dong Kim, Kyung Chun Kim
Spatial and temporal variations of the hemodynamic features occur under pulsatile conditions in complex vessel geometry. Wall shear stress affected by the disturbed flow can result in endothelial cell dysfunction, which leads to atherogenesis and thrombosis. Therefore, detailed understanding of the hemodynamic characteristics in a curved stenosed channel is highly important when examining the pathological effects of hemodynamic phenomena on the progression of atherosclerosis. The present study measures the velocity fields of pulsatile flows with three different Reynolds numbers in 3D curved vessel models with stenosis using time-resolved particle image velocimetry (PIV)...
2017: PloS One
Scott Segal, Carlo Pancaro, Iwona Bonney, James E Marchand
BACKGROUND: Women laboring with epidural analgesia experience fever much more frequently than do women who chose other forms of analgesia, and maternal intrapartum fever is associated with numerous adverse consequences, including brain injury in the fetus. We developed a model of noninfectious inflammatory fever in the near-term pregnant rat to simulate the pathophysiology of epidural-associated fever and hypothesized that it would produce fetal brain inflammation. METHODS: Twenty-four pregnant Sprague-Dawley rats were studied at 20 days gestation (term: 22 days)...
October 17, 2017: Anesthesia and Analgesia
Guangfang Shao, Suping Zhang, Jihua Nie, Jianxiang Li, Jian Tong
Changes in diurnal rhythmicity in blood pressure (BP) are associated with hypertension and consequent cardiovascular damage. The involvement of diurnal rhythmicity as a pathogenic factor in hypertension is not fully understood. Since the hormone melatonin (MLT) regulates circadian rhythm, it was also of interest to determine whether this hormone played a role in hypertension-related alterations in circadian rhythm. Thus the aim of this study was to examine the mechanisms underlying MLT-mediated antihypertension...
October 19, 2017: Journal of Toxicology and Environmental Health. Part A
Yawen Ma, Yixue Xue, Xiaobai Liu, Chengbin Qu, Heng Cai, Ping Wang, Zhiqing Li, Zhen Li, Yunhui Liu
Malignant glioma, the most common intracranial primary tumor, is characterized by increased angiogenesis. Accumulating evidence has shown that long non-coding RNAs (lncRNAs) play an important role in a variety of biological behaviors of tumors. However, the role of lncRNAs in the regulation of glioma vascular endothelial cell function remains to be investigated. To simulate the glioma microenvironment, we applied glioma conditioned medium (GCM) to human cerebral microvascular endothelial cells (hCMECs). In the present study, the lncRNA SNHG15 was found to be highly expressed in glioma vascular endothelial cells...
September 21, 2017: Oncology Reports
Abhijit Chakraborty, Ferhat Ay
Motivation: Eukaryotic chromosomes adapt a complex and highly dynamic three-dimensional (3D) structure, which profoundly affects different cellular functions and outcomes including changes in epigenetic landscape and in gene expression. Making the scenario even more complex, cancer cells harbor chromosomal abnormalities (e.g., copy number variations (CNVs) and translocations) altering their genomes both at the sequence level and at the level of 3D organization. High-throughput chromosome conformation capture techniques (e...
October 18, 2017: Bioinformatics
Diana M Gentry, Elena S Amador, Morgan L Cable, Nosheen Chaudry, Thomas Cullen, Malene B Jacobsen, Gayathri Murukesan, Edward W Schwieterman, Adam H Stevens, Amanda Stockton, George Tan, Chang Yin, David C Cullen, Wolf Geppert
We conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmvörðuháls lava fields (Iceland). Sites were selected to be "homogeneous" at a coarse remote sensing resolution (10-100 m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1 m, 10 m, 100 m, and >1 km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests)...
October 2017: Astrobiology
J A Langille, B Solheim, A Bourassa, D Degenstein, S Brown, G G Shepherd
Spatial heterodyne spectroscopy (SHS) has been successfully applied to measure variations in water vapor pressure in the lab. An imaging system is combined with a monolithic field-widened SHS to observe a white-light source through a 1 m length water vapor cell that is designed to produce predictable variations in the water vapor pressure. The performance of the spectrometer design is examined by comparing spectra simulated using a radiative transfer model to observed spectra at several cell pressures. The intended application of the instrument to vertically resolve the water vapor profile in the upper troposphere and lower stratosphere using limb-scattered radiation in a vibrational band of water (1363-1366 nm) is also introduced...
May 20, 2017: Applied Optics
Jianbo Du, Daojing Li, Meng Ma
To improve the target detection performance of inverse synthetic aperture ladar (ISAL) under the situation that there is Doppler bandwidth ambiguity, we consider energy accumulation of echo signals along a range through matched illumination. However, since the target impulse responses change with the target aspect angle, the phase shifts along slow-time between range cells are different, and the output of matched illumination fluctuates along slow-time. To reduce the slow-time fluctuation of matched illumination under additive white Gaussian noise assumption, we have proposed an interferometric ISAL (InISAL) target detection method based on interferometry processing and principal component analysis (PCA) in this paper...
September 20, 2017: Applied Optics
Yasuhiko Takeda, Hideo Iizuka, Noboru Yamada, Tadashi Ito
We have proposed a light-trapping concept for photovoltaic (PV) cells under monochromatic illumination with restricted incident angles. We employed a configuration consisting of a shortpass filter (SPF) on the front surface and a diffuse reflector on the rear surface of the cell. The SPF was designed so that it functioned as a polarization-insensitive angle-selective filter. We fabricated 30-80-μm-thick crystalline silicon samples for incident angles changing within 30°, and analyzed the measured results using a ray-trace simulation with the Monte Carlo method...
July 10, 2017: Applied Optics
Y Wei, M Ibison, G Xia, J D A Smith, C P Welsch
This paper investigates numerically dual-grating dielectric laser-driven accelerators driven by a pulse-front-tilted (PFT) laser, which extends the interaction length and boosts the electrons' energy gain. The optical system necessary to generate PFT laser beams with an ultrashort pulse duration of 100 fs is also studied in detail. Through two-dimensional particle-in-cell simulations, we show that such a PFT laser effectively increases the energy gain by (91±25) % compared to that of a normally incident laser with a waist radius of 50 μm for a 100-period dual-grating structure...
October 10, 2017: Applied Optics
Jian Ma, Ping An, Liquan Shen, Kai Li
Stereoscopic imaging technology has been growingly prevalent driven by both the entertainment industry and scientific applications in today's world. But objective quality assessment of stereoscopic images is a challenging task. In this paper, we propose a novel stereoscopic image quality assessment (SIQA) method by jointly considering monocular perception and binocular interaction. As the most significant contribution of this study, binocular perceptual properties of simple and complex cells are considered for full-reference (FR) SIQA...
October 10, 2017: Applied Optics
Shereena Joseph, Joby Joseph
We have investigated the antireflection and light trapping properties of two-dimensional grating arrays in the hexagonal symmetry with various texture morphologies. Optical simulation based on finite-difference time-domain (FDTD) analysis is carried out to understand the role of the structure profile for different periodicities and heights to achieve enhanced light trapping. The considered active medium of interest is 200-nm-thick hydrogenated amorphous silicon. Although the considered texture profiles possess an incremental change of refractive index from incident medium to active medium, a parabolic-shaped front side texture provides better antireflection effects owing to its high diffraction efficiencies in the higher-order modes as compared to other pattern morphologies...
June 10, 2017: Applied Optics
Marina E Inchaussandague, Diana C Skigin, Andrés E Dolinko
We explore the electromagnetic response of the pellicle of selected species of euglenoids. These microorganisms are bounded by a typical surface pellicle formed by S-shaped overlapping bands that resemble a corrugated film. We investigate the role played by this structure in the protection of the cell against UV radiation. By considering the pellicle as a periodically corrugated film of finite thickness, we applied the C-method to compute the reflectance spectra. The far-field results revealed reflectance peaks with a Q-factor larger than 10(3) in the UV region for all the illumination conditions investigated...
June 20, 2017: Applied Optics
Saikat Bhattacharya, Divya Reddy, Vinod Jani, Nikhil Gadewal, Sanket Shah, Raja Reddy, Kakoli Bose, Uddhavesh Sonavane, Rajendra Joshi, Sanjay Gupta
BACKGROUND: The distinct functional effects of the replication-dependent histone H2A isoforms have been demonstrated; however, the mechanistic basis of the non-redundancy remains unclear. Here, we have investigated the specific functional contribution of the histone H2A isoform H2A1H, which differs from another isoform H2A2A3 in the identity of only three amino acids. RESULTS: H2A1H exhibits varied expression levels in different normal tissues and human cancer cell lines (H2A1C in humans)...
October 18, 2017: Epigenetics & Chromatin
Luilli López-Contreras, Verónica Ivonne Hernández-Ramírez, Mayra Herrera-Martínez, Sarita Montaño, Luis Alejandro Constantino-Jonapa, Bibiana Chávez-Munguía, Patricia Talamás-Rohana
BACKGROUND: The abundant number of kinases that Entamoeba histolytica possesses allows us to assume that the regulation of cellular functions by phosphorylation-dephosphorylation processes is very important. However, the kinases responsible for the phosphorylation in Entamoeba spp. vary in the structure of their domains and, therefore, could be responsible for the unusual biological characteristics of this parasite. In higher eukaryotes, Src kinases share conserved structural domains and are very important in the regulation of the actin cytoskeleton...
October 18, 2017: Parasites & Vectors
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"