scholarly journals Investigation of the impact of simulated solar radiation on the micro- and nanoscale morphology and mechanical properties of a sheet moulded composite surface

2016 ◽  
Vol 34 (3) ◽  
pp. 641-649 ◽  
Author(s):  
Andrzej Sikora ◽  
Łukasz Bednarz ◽  
Tomasz Fałat ◽  
Marek Wałecki ◽  
Maria Adamowska
Keyword(s):  
High Resolution ◽  
Solar Radiation ◽  
Material Degradation ◽  
Significant Deterioration ◽  
Composite Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Applied Approach ◽  
Simulated Solar Radiation ◽  
The Impact

AbstractIn this paper we present the results of investigation of micro- and nanoscale degradation of a sheet moulded composite exposed to simulated solar radiation. Utilization of high resolution methods such as atomic force microscopy, optical profilometry and microcomputer tomography allowed us to provide the evidence of significant deterioration of the surface as well as the material few microns in depth. Additionally, the typically used macroscopic investigations, such as wettability and flexural strength, were performed to observe the impact of weathering process. It was also shown that high resolution techniques provide superior sensitivity of the material degradation detection. The particular effectiveness of the applied approach was related to the structure of investigated material, as due to its degradation, a number of voids appeared, causing a significant roughness increase. In addition, the impact of light radiation could be compared to other environmental conditions maintained in the climatic chamber. It should be underlined, that according to our knowledge, such a study has not been performed so far.

scholarly journals Exploring Intramolecular Methyl–Methyl Coupling on a Metal Surface for Edge-Extended Graphene Nanoribbons

2021 ◽  
Vol 03 (02) ◽  
pp. 128-133
Author(s):  
Zijie Qiu ◽  
Qiang Sun ◽  
Shiyong Wang ◽  
Gabriela Borin Barin ◽  
Bastian Dumslaff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
High Resolution ◽  
Graphene Nanoribbons ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Methyl Methyl ◽  
Atomic Force ◽  
Edge Extension

Intramolecular methyl–methyl coupling on Au (111) is explored as a new on-surface protocol for edge extension in graphene nanoribbons (GNRs). Characterized by high-resolution scanning tunneling microscopy, noncontact atomic force microscopy, and Raman spectroscopy, the methyl–methyl coupling is proven to indeed proceed at the armchair edges of the GNRs, forming six-membered rings with sp3- or sp2-hybridized carbons.

scholarly journals Extracellular Vesicles Analysis in the COVID-19 Era: Insights on Serum Inactivation Protocols towards Downstream Isolation and Analysis

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 544
Author(s):  
Roberto Frigerio ◽  
Angelo Musicò ◽  
Marco Brucale ◽  
Andrea Ridolfi ◽  
Silvia Galbiati ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Analytical Techniques ◽  
Heat Inactivation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Droplet Pcr ◽  
Detergent Treatment ◽  
Routine Procedures ◽  
The Impact ◽  
Mirna Content

Since the outbreak of the COVID-19 crisis, the handling of biological samples from confirmed or suspected SARS-CoV-2-positive individuals demanded the use of inactivation protocols to ensure laboratory operators’ safety. While not standardized, these practices can be roughly divided into two categories, namely heat inactivation and solvent-detergent treatments. These routine procedures should also apply to samples intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus-inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the analytical community, yet deep investigations in this direction have not yet been reported. We here provide insights into SARS-CoV-2 inactivation practices to be adopted prior to serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entails the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of a set of complementary analytical techniques: Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat treatment; however, it is accompanied by a marked enrichment in EVs-associated contaminants. On the other hand, solvent/detergent treatment is promising for small EVs (<150 nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.

Imaging of Xenopus laevis Oocyte Plasma Membrane in Physiological-Like Conditions by Atomic Force Microscopy

2013 ◽  
Vol 19 (5) ◽  
pp. 1358-1363 ◽  
Author(s):  
Massimo Santacroce ◽  
Federica Daniele ◽  
Andrea Cremona ◽  
Diletta Scaccabarozzi ◽  
Michela Castagna ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Plasma Membrane ◽  
High Resolution ◽  
Membrane Proteins ◽  
Xenopus Laevis ◽  
Functional Study ◽  
Xenopus Laevis Oocyte ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging

AbstractXenopus laevis oocytes are an interesting model for the study of many developmental mechanisms because of their dimensions and the ease with which they can be manipulated. In addition, they are widely employed systems for the expression and functional study of heterologous proteins, which can be expressed with high efficiency on their plasma membrane. Here we applied atomic force microscopy (AFM) to the study of the plasma membrane of X. laevis oocytes. In particular, we developed and optimized a new sample preparation protocol, based on the purification of plasma membranes by ultracentrifugation on a sucrose gradient, to perform a high-resolution AFM imaging of X. laevis oocyte plasma membrane in physiological-like conditions. Reproducible AFM topographs allowed visualization and dimensional characterization of membrane patches, whose height corresponds to a single lipid bilayer, as well as the presence of nanometer structures embedded in the plasma membrane and identified as native membrane proteins. The described method appears to be an applicable tool for performing high-resolution AFM imaging of X. laevis oocyte plasma membrane in a physiological-like environment, thus opening promising perspectives for studying in situ cloned membrane proteins of relevant biomedical/pharmacological interest expressed in this biological system.

Structuring of Silicon Wafer Surfaces on the Sub-100 nm Scale by Hydrogen Plasma Treatments

2003 ◽  
Vol 788 ◽  
Author(s):  
R. Job ◽  
Y. Ma ◽  
A. G. Ulyashin
Keyword(s):  
Hydrogen Plasma ◽  
Structural Defects ◽  
Process Conditions ◽  
Force Microscopy ◽  
Czochralski Silicon ◽  
Atomic Force ◽  
Nano Structures ◽  
Plasma Treatments ◽  
The Impact ◽  
Wafer Surfaces

ABSTRACTHydrogen plasma treatments applied on standard Czochralski silicon (Cz Si) wafers cause a structuring of the surface regions on the sub-100 nm scale, i.e. a thin ‘nano-structured’ Si layer is created up to a depth of ∼ 150 nm. The formation of the ‘nano-structures’ and their evolution in dependence on the process conditions was studied. The impact of post-hydrogenation annealing on the morphology of the structural defects was studied up to 1200 °C. The H-plasma treated and annealed samples were analyzed at surface and sub-surface regions by scanning electron microscopy (SEM), atomic force microscopy (AFM), and μ-Raman spectroscopy.

High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Epitaxial Relationship ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Α Al2o3 ◽  
Relationship Of

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.

High-Resolution Frequency-Modulation Atomic Force Microscopy in Liquids Using Electrostatic Excitation Method

2010 ◽  
Vol 3 (6) ◽  
pp. 065205 ◽  
Author(s):  
Ken-ichi Umeda ◽  
Noriaki Oyabu ◽  
Kei Kobayashi ◽  
Yoshiki Hirata ◽  
Kazumi Matsushige ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Frequency Modulation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Excitation Method

scholarly journals Deswelling Induced Morphological Changes in Dual pH and Temperature Responsive Ultra-Low Crosslinked Poly (N-Isopropyl Acrylamide)-Co-Acrylic Acid Microgels

2018 ◽  
Author(s):  
Molla Islam ◽  
Maddie Tumbarello ◽  
Andrew Lyon
Keyword(s):  
Light Scattering ◽  
Acrylic Acid ◽  
Morphological Changes ◽  
Scattering Data ◽  
Ionization State ◽  
Force Microscopy ◽  
Temperature Responsive ◽  
Atomic Force ◽  
Isopropyl Acrylamide ◽  
The Impact

<div>We demonstrated the deswelling induced morphological change in dual pH and Temperature responsive ultra-low crosslinked Poly (N-isopropyl acrylamide)-co-acrylic acid microgels. The responsivity with pH and temperature were studied by light scattering and atomic force microscopy. Light scattering data suggest that at pH 4.5 the microgels undergo multiple transitions associated with collapse of pNIPAm-rich segments and repulsion between the AAc-rich segments. The evolution of punctate structures around the periphery or throughout the whole microgels at pH 4.5 and 6.5 respectively was revealed by AFM, further illustrating the heterogeneous deswelling present in the ionized copolymer microgels.</div><div>The impact of this study and understanding how ionization state of copolymer dictates the overall structural properties of microgels will widen our understanding for their applications in biotechnology</div><div><b><br></b></div>

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