keyword
MENU ▼
Read by QxMD icon Read
search

Atomic force microscopy

keyword
https://www.readbyqxmd.com/read/29160880/low-temperature-growth-of-gallium-oxide-thin-films-via-plasma-enhanced-atomic-layer-deposition
#1
Richard O'Donoghue, Julian Rechmann, Morteza Aghaee, Detlef Rogalla, Hans-Werner Becker, Mariadriana Creatore, Andreas Dirk Wieck, Anjana Devi
Herein we describe an efficient low temperature (60-160 °C) plasma enhanced atomic layer deposition (PEALD) process for gallium oxide (Ga2O3) thin films using hexakis(dimethylamido)digallium [Ga(NMe2)3]2 with oxygen (O2) plasma on Si(100). The use of O2 plasma was found to have a significant improvement on the growth rate and deposition temperature when compared to former Ga2O3 processes. The process yielded the second highest growth rates (1.5 Å per cycle) in terms of Ga2O3 ALD and the lowest temperature to date for the ALD growth of Ga2O3 and typical ALD characteristics were determined...
November 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29160836/an-in-vitro-study-of-the-photodynamic-effectiveness-of-go-ag-nanocomposites-against-human-breast-cancer-cells
#2
Fozia Shaheen, Muhammad Hammad Aziz, Muhammad Fakhar-E-Alam, Muhammad Atif, Mahvish Fatima, Riaz Ahmad, Atif Hanif, Saqib Anwar, Fatima Zafar, Ghazanfar Abbas, Syed Mansoor Ali, Mukhtar Ahmed
Graphene-based materials have garnered significant attention because of their versatile bioapplications and extraordinary properties. Graphene oxide (GO) is an extremely oxidized form of graphene accompanied by the functional groups of oxygen on its surface. GO is an outstanding platform on which to pacify silver nanoparticles (Ag NPs), which gives rise to the graphene oxide-silver nanoparticle (GO-Ag) nanocomposite. In this experimental study, the toxicity of graphene oxide-silver (GO-Ag) nanocomposites was assessed in an in vitro human breast cancer model to optimize the parameters of photodynamic therapy...
November 21, 2017: Nanomaterials
https://www.readbyqxmd.com/read/29160692/s100a9-protein-aggregates-boost-hippocampal-glutamate-modifying-monoaminergic-neurochemistry-a-glutamate-antibody-sensitive-outcome-on-alzheimer-like-memory-decline
#3
Marina A Gruden, Tatiana V Davydova, Vladimir S Kudrin, Chao Wang, Victor B Narkevich, Ludmilla A Morozova-Roche, Robert D E Sewell
Alzheimer's disease (AD) involves dementia conceivably arising from integrated inflammatory processes, amyloidogenesis and neuronal apoptosis. Glutamate can also cause neuronal death via excitotoxicity and this is similarly implicated in some neurological diseases. The aim was to examine treatment with in vitro generated pro-inflammatory protein S100A9 aggregate species alone or with glutamate antibodies (Glu-Abs) on Morris water maze (MWM) spatial learning and memory performance in 12-month old mice. Amino acid and monoamine cerebral neurotransmitter metabolic changes were concurrently monitored...
November 21, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/29160129/injectable-nanosilica-chitosan-microparticles-for-bone-regeneration-applications
#4
Bipin Gaihre, Beata Lecka-Czernik, Ambalangodage C Jayasuriya
This study was aimed at assessing the effects of silica nanopowder incorporation into chitosan-tripolyphosphate microparticles with the ultimate goal of improving their osteogenic properties. The microparticles were prepared by simple coacervation technique and silica nanopowder was added at 0% (C), 2.5% (S1), 5% (S2) and 10% (S3) (w/w) to chitosan. We observed that this simple incorporation of silica nanopowder improved the growth and proliferation of osteoblasts along the surface of the microparticles. In addition, the composite microparticles also showed the increased expression of alkaline phosphatase and osteoblast specific genes...
January 1, 2017: Journal of Biomaterials Applications
https://www.readbyqxmd.com/read/29160067/molecular-tension-probes-for-imaging-forces-at-the-cell-surface
#5
Yang Liu, Kornelia Galior, Victor Pui-Yan Ma, Khalid Salaita
Mechanical forces are essential for a variety of biological processes ranging from transcription and translation to cell adhesion, migration, and differentiation. Through the activation of mechanosensitive signaling pathways, cells sense and respond to physical stimuli from the surrounding environment, a process widely known as mechanotransduction. At the cell membrane, many signaling receptors, such as integrins, cadherins and T- or B-cell receptors, bind to their ligands on the surface of adjacent cells or the extracellular matrix (ECM) to mediate mechanotransduction...
November 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/29159794/high-fat-high-sugar-diet-induced-subendothelial-matrix-stiffening-is-mitigated-by-exercise
#6
Julie C Kohn, Julian Azar, Francesca Seta, Cynthia A Reinhart-King
Consumption of a high-fat, high-sugar diet and sedentary lifestyle are correlated with bulk arterial stiffening. While measurements of bulk arterial stiffening are used to assess cardiovascular health clinically, they cannot account for changes to the tissue occurring on the cellular scale. The compliance of the subendothelial matrix in the intima mediates vascular permeability, an initiating step in atherosclerosis. High-fat, high-sugar diet consumption and a sedentary lifestyle both cause micro-scale subendothelial matrix stiffening, but the impact of these factors in concert remains unknown...
November 20, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/29159501/a-fundamental-study-of-photoluminescence-modulation-from-dna-wrapped-single-walled-carbon-nanotubes
#7
Shusuke Oura, Masahiro Ito, Yoshikazu Homma, Kazuo Umemura
In this study, we investigated the interaction of base sequence-assigned single-stranded DNA (ssDNA) molecules with the surfaces of single-walled carbon nanotube (SWNT)-thymine (T30)/cytosine (C30) hybrids (T30/C30-SWNT), by measuring the modulation of near-infrared (NIR) photoluminescence (PL). Significant PL shifts were observed when T30/C30-SWNTs were reacted with 30-mers of adenine (A30)/guanine (G30). In contrast, when non-complementary ssDNA was used, no significant energy shift was observed in the PL modulation except when T30-SWNTs were reacted with G30...
November 20, 2017: European Biophysics Journal: EBJ
https://www.readbyqxmd.com/read/29158540/calcium-binding-and-voltage-gating-in-cx46-hemichannels
#8
Bernardo I Pinto, Amaury Pupo, Isaac E García, Karel Mena-Ulecia, Agustín D Martínez, Ramón Latorre, Carlos Gonzalez
The opening of connexin (Cx) hemichannels in the membrane is tightly regulated by calcium (Ca(2+)) and membrane voltage. Electrophysiological and atomic force microscopy experiments indicate that Ca(2+) stabilizes the hemichannel closed state. However, structural data show that Ca(2+) binding induces an electrostatic seal preventing ion transport without significant structural rearrangements. In agreement with the closed-state stabilization hypothesis, we found that the apparent Ca(2+) sensitivity is increased as the voltage is made more negative...
November 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29157609/specific-recognition-of-polyphenols-by-molecularly-imprinted-polymers-based-on-a-ternary-deep-eutectic-solvent
#9
Najing Fu, Liteng Li, Xiao Liu, Nian Fu, Chenchen Zhang, Liandong Hu, Donghao Li, Baokun Tang, Tao Zhu
Typically, a target compound is selected as a template for a molecularly imprinted polymer (MIP); however, some target compounds are not suitable as templates because of their poor solubility. Using the tailoring properties of a deep eutectic solvent (DES), the insoluble target compound caffeic acid was transformed into a ternary choline chloride-caffeic acid-ethylene glycol (ChCl-CA-EG) DES, which was then employed as a template to prepare MIPs. The ternary DES-based MIPs were characterized by Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy, and atomic force microscopy...
November 7, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29156631/morphology-and-mechanical-properties-of-polyimide-films-the-effects-of-uv-irradiation-on-microscale-surface
#10
Changzi Qu, Junsong Hu, Xing Liu, Zheng Li, Yanhuai Ding
As an attractive dielectric material, polyimide has been widely used in the field of electronics, aerospace, and automobiles due to its useful mechanical properties and good chemical resistance. UV irradiation was considered to be the main factor related to the damage and failure of polyimide. Here the effects of UV irradiation on the surface morphology and microscale mechanical properties of polyimide films are characterized by atomic force microscopy (AFM). The surface roughness of the UV-irradiated samples developed and the mechanical properties degraded with the radiation dose increased...
November 20, 2017: Materials
https://www.readbyqxmd.com/read/29156338/effect-of-laminaria-japonica-polysaccharides-on-lipids-monolayers-at-the-air-water-surface
#11
Juanjuan Yang, Changchun Hao, Runguang Sun
In this paper, we examined the effect of Laminaria japonica polysaccharides (LJP) on cationic 1,2-Dioleoyl-3-Trimethylammonium-Propane (DOTAP) and anionic 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-1-glycerol] (DPPG) monolayers at the air-water interface by the pressure-area isotherms (π-A), adsorption curves (π-t) and morphology measurements with atomic force microscopy (AFM) technique. The π-A curves revealed that the isotherms shifted to larger mean molecular area with progressive addition of LJP into subphase for both DOTAP and DPPG monolayers...
November 17, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/29155397/facile-phyto-mediated-synthesis-of-silver-nanoparticles-using-chinese-winter-jujube-ziziphus-jujuba-mill-cv-dongzao-extract-and-their-antibacterial-catalytic-properties
#12
Chun-Gang Yuan, Can Huo, Bing Gui, Jing-Fu Liu, Yong-Sheng Chen
The aqueous extract of Chinese winter jujube (Ziziphus jujuba Mill. cv. Dongzao) was used as reducing and capping agents for the synthesis of silver nanoparticles (AgNPs) for the first time. The resulting AgNPs were characterised by UV/Visible (UV-Vis) spectroscopy, atomic force microscope, transmission electron microscopy, selected area electron diffraction, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray and Fourier transform infrared spectroscopy (FTIR). The colloidal solution of AgNPs gave a maximum UV-Vis absorbance at 446 nm...
December 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/29155396/biomimetic-synthesis-of-silver-nanoparticles-from-streptomyces-atrovirens-and-their-potential-anticancer-activity-against-human-breast-cancer-cells
#13
Ramasamy Subbaiya, Muthupandian Saravanan, Andavar Raja Priya, Konathala Ravi Shankar, Masilamani Selvam, Muhammad Ovais, Ramachandran Balajee, Hamed Barabadi
Silver nanoparticles (AgNPs) have been undeniable for its antimicrobial activity while its antitumour potential is still limited. Therefore, the present study focused on determining cytotoxic effects of AgNPs on Michigan cancer foundation-7 (MCF-7) breast cancer cells and its corresponding mechanism of cell death. Herein, the authors developed a bio-reduction method for AgNPs synthesis using actinomycetes isolated from marine soil sample. The isolated strain was identified by 16s ribotyping method and it was found to be Streptomyces atrovirens...
December 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/29153860/the-antimicrobial-peptide-hs-1-inhibits-dengue-virus-infection
#14
Juliana M C Monteiro, Michelle D Oliveira, Roberto S Dias, Lorena Nacif-Marçal, Renato N Feio, Sukarno O Ferreira, Leandro L Oliveira, Cynthia C Silva, Sérgio O Paula
Dengue virus (DENV) is an arbovirus that belongs to the Flaviviridae family. Studies reveal that peptides secreted by amphibians have many functions, such as antiviral and antimicrobial activities. As there is no antiviral drug effective against the DENV, the antiviral activity of a synthetic peptide called HS-1, derived from the secretion of the anuran Hypsiboas semilineatus, has been evaluated. The assays of neutralization in the Vero cells show a complete inhibition of infection of the serotypes 2 and 3...
November 16, 2017: Virology
https://www.readbyqxmd.com/read/29153710/silver-nanoparticle-fibrinogen-bilayers-mechanism-of-formation-and-stability-determined-by-in-situ-electrokinetic-measurements
#15
Monika Wasilewska, Zbigniew Adamczyk, Magdalena Oćwieja, Dominika Wojnar, Paulina Żeliszewska
The kinetics of negatively charged silver nanoparticle (AgNP) deposition on the supporting fibrinogen monolayers of well-characterized coverage was determined by the atomic force microscopy (AFM). The kinetics was quantitatively interpreted in terms of the hybrid random sequential adsorption model. The electrokinetic properties of the fibrinogen monolayers and fibrinogen/AgNP bilayers were thoroughly characterized in situ by the streaming potential measurements. These results were interpreted in terms of the general electrokinetic model expressing the particle coverage in terms of the zeta potential of the bilayers...
November 8, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29152798/atomic-force-microscopy-for-biomechanical-and-structural-analysis-of-human-dermis-a-complementary-tool-for-medical-diagnosis-and-therapy-monitoring
#16
Leonardo Peñuela, Carola Negro, Michela Massa, Erica Repaci, Emanuele Cozzani, Aurora Parodi, Silvia Scaglione, Rodolfo Quarto, Roberto Raiteri
Skin mechanical properties are usually measured considering the entire skin thickness and very little is known about the mechanical behavior of individual skin layers. We propose atomic force microscopy (AFM) as a tool to quantify nanoscale changes in the biomechanical properties and ultrastructure of human papillary dermis exposed to different mechanical and physical stimuli. Samples from three human skin biopsies were studied: one stretched by obesity, one subjected to a high level of sun-exposure, and normal skin as control...
November 20, 2017: Experimental Dermatology
https://www.readbyqxmd.com/read/29152621/improvement-in-the-bonding-of-y-tzp-by-room-temperature-ultrasonic-hf-etching
#17
Haifeng Xie, Yi Cheng, Ying Chen, Mengke Qian, Yang Xia, Chen Chen
PURPOSE: To investigate the effects of room-temperature etching with hydrofluoric acid (HF) in the presence and absence of ultrasonic irradiation on the bonding of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) to resin. MATERIALS AND METHODS: Y-TZP specimens were etched with 40% HF at room temperature for different time periods (2, 5, 10, 15, 30, 60, and 90 min) with and without ultrasonic exposure. The surface roughness, micromorphology, dimensions, and phases of the treated Y-TZP specimens were evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM), digital caliper measurement, and x-ray diffraction, respectively...
November 17, 2017: Journal of Adhesive Dentistry
https://www.readbyqxmd.com/read/29150942/a-novel-epididymal-quiescence-factor-inhibits-sperm-motility-by-modulating-nos-activity-and-intracellular-no-cgmp-pathway
#18
Prasanta Ghosh, Sandipan Mukherjee, Arpita Bhoumik, Sandhya Rekha Dungdung
Mature and potentially motile spermatozoa stored in cauda epididymis in an inactive state for approximately 30 days; however during ejaculation they regain motility. To understand the actual molecular mechanism of the sperm quiescence during caudal stay, a proteinaceous quiescence factor (QF) has been purified from caprine epididymal plasma to apparent homogeneity. In the present study complete purification, detailed characterization as well as mechanistic pathway of QF has been described. QF was purified to 215 fold with 45% activity recovery...
November 18, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/29150807/single-cell-versus-large-population-analysis-cell-variability-in-elemental-intracellular-concentration-and-distribution
#19
Emil Malucelli, Alessandra Procopio, Michela Fratini, Alessandra Gianoncelli, Andrea Notargiacomo, Lucia Merolle, Azzurra Sargenti, Sara Castiglioni, Concettina Cappadone, Giovanna Farruggia, Marco Lombardo, Stefano Lagomarsino, Jeanette A Maier, Stefano Iotti
The quantification of elemental concentration in cells is usually performed by analytical assays on large populations missing peculiar but important rare cells. The present article aims at comparing the elemental quantification in single cells and cell population in three different cell types using a new approach for single cells elemental analysis performed at sub-micrometer scale combining X-ray fluorescence microscopy and atomic force microscopy. The attention is focused on the light element Mg, exploiting the opportunity to compare the single cell quantification to the cell population analysis carried out by a highly Mg-selective fluorescent chemosensor...
November 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29150558/branched-pectic-galactan-in-phloem-sieve-element-cell-walls-implications-for-cell-mechanics
#20
Thomas A Torode, Rachel E O'Neill, Susan E Marcus, Valerie Cornuault, Sara Pose-Albacete, Rebecca P Lauder, Stjepan Kresimir Kracun, Maja Gro Rydahl, Mathias C F Andersen, William George Tycho Willats, Siobhan Ariel Braybrook, Belinda J Townsend, Mads H Clausen, J Paul Knox
A major question in plant biology concerns the specification and functional differentiation of cell types. This is in the context of constraints imposed by networks of cell walls that both adhere cells and contribute to the form and function of developing organs. Here, we report the identification of a glycan epitope that is specific to phloem sieve element cell walls in several systems. A monoclonal antibody, designated LM26, binds to the cell wall of phloem sieve elements in stems of Arabidopsis thaliana, Miscanthus x giganteus and notably sugar beet (Beta vulgaris) roots where phloem identification is an important factor for the study of phloem unloading of sucrose...
November 17, 2017: Plant Physiology
keyword
keyword
63989
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"