scholarly journals The Role of Modification of the Structure of Water and Water-Containing Systems in Changing Their Biological, Therapeutic, and Other Properties Overview

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2441
Author(s):  
Galina Sidorenko ◽  
Mitja Brilly ◽  
Boris Laptev ◽  
Nikolay Gorlenko ◽  
Leonid Antoshkin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mineral Water ◽  
Structural Changes ◽  
Water Clusters ◽  
Force Microscopy ◽  
Structure Of Water ◽  
Atomic Force ◽  
The Impact ◽  
Non Destructive

Based on published research on modifying the structure of water and water-containing systems, we assess external influence methods: temperature, magnetic field, light radiation, and their combination. We evaluate changes in the electrophysical, photo- and pH-metric biological, therapeutic, and other properties of water systems using non-destructive electrophysical research methods, i.e., thermometry, pH, laser interference, dynamic light scattering, microelectrophoresis, conductivity, surface tension, dielectric constant, polarimetric measurements, atomic force microscopy, and UV and EPR spectroscopy. The effects of temperature or magnetic field lead to a change in the content and size of water clusters, and physicochemical, biological, therapeutic, and other changes in the properties of water and water-containing systems. The combined effect of a magnetic field and curative mud and the impact of magnetised mineral water have a more pronounced therapeutic effect than only mineral water or curative mud. The data presented indirectly indicate structural changes in water and water-containing systems. We conclude that the primary mechanism of action of a magnetic field, light, or a combination of these factors on water and water-containing systems, including mineral water and therapeutic mud, is a change in the structure of water.

Impact of the LED-based light source working regime on the degradation of polymethyl methacrylate

2019 ◽  
Vol 52 (1) ◽  
pp. 94-105 ◽  
Author(s):  
A Sikora ◽  
K Tomczuk
Keyword(s):  
Polymethyl Methacrylate ◽  
Pulse Width Modulation ◽  
Morphological Changes ◽  
Detection Sensitivity ◽  
Force Microscopy ◽  
Dc Power ◽  
Atomic Force ◽  
High Roughness ◽  
The Impact ◽  
Non Destructive

The popularity of LED-based luminaires has increased enormously in recent years. Every such luminaire consists of several elements including a polymer-based transparent housing, yet some of the ageing aspects of specific luminaire materials have not been investigated. In this paper, we present research aimed at determining the impact of LED lamp powering mode on polymer material deterioration. In the experiment, three LED lamp operating systems based on two different pulse width modulation units and one DC power source were used to induce deterioration in a polymethyl methacrylate sample. Two types of LEDs, white and ultraviolet, were considered as the most significant in terms of the impact on the material. Observations of the surface's morphological changes were performed to enable non-destructive investigation of the degradation of the exposed samples. In order to obtain high roughness detection sensitivity, atomic force microscopy was used. We observed various ageing ratios of the material, despite the fact that total average optical energy for specific wavelengths was equal for all samples. The importance of these findings for designing modern luminaires is discussed.

scholarly journals Low Energy Optical Excitations as an Indicator of Structural Changes Initiated at the Termini of Amyloid Proteins

2018 ◽  
Author(s):  
KwangHyok Jong ◽  
Yavar T. Azar ◽  
Luca Grisanti ◽  
Amberley D. Stephens ◽  
Saul T.E. Jones ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Optical Properties ◽  
Amino Acid ◽  
Optical Absorption ◽  
Structural Changes ◽  
Low Energy ◽  
Force Microscopy ◽  
Atomic Force ◽  
N Terminus

<div>We combine absorption and fluorscence spectroscopy experiments and theoretical modeling to specifically examine the role of termini interactions on the optical properties.</div><div><div>Optical absorption and fluorescence is measured for a six-chain amino acid 2Y3J (AIIGLM) which forms a segment of the full amyloid beta 1-40. In order to explore the sensitivity of the optical properties to the termini interactions, the experiments were repeated by acetylating the N-terminus.</div><div>Although atomic force microscopy experiments indicate the formation of some form of fibrilar or crystal aggregates in both systems, the optical properties are strikingly different - acetylation significantly reduces optical activity between 280-350 nm.</div></div>

scholarly journals Clustering of desmosomal cadherins by desmoplakin is essential for cell-cell adhesion

2020 ◽  
Author(s):  
Marie-Therès Wanuske ◽  
Dominique Brantschen ◽  
Camilla Schinner ◽  
Chiara Stüdle ◽  
Elias Walter ◽  
...  
Keyword(s):  
Adhesion Molecules ◽  
Human Keratinocytes ◽  
Intercellular Adhesion ◽  
Force Microscopy ◽  
Superresolution Imaging ◽  
Desmosomal Cadherins ◽  
Atomic Force ◽  
Small Clusters ◽  
The Impact

ABSTRACTDesmoplakin (Dp) localizes to desmosomes, linking clusters of desmosomal adhesion molecules to the intermediate filament cytoskeleton. Here, we generated Dp knockout (ko) cell lines of human keratinocytes to study the impact on desmosomal adhesion molecules and desmosome turnover using atomic force microscopy and superresolution imaging. In comparison to ko of another desmosomal component, plakoglobin (Pg), loss of Dp resulted in absence of desmosomes and drastically impaired cell cohesion. In Dp ko, the desmosomal adhesion molecules desmoglein 2 (Dsg2) and desmocollin 3 (Dsc3) were redistributed into small clusters in the cell membrane with no further increase in loss of intercellular adhesion by silencing of Dsg2. This suggests that extradesmosomal cadherins do not significantly contribute to cell cohesion but rather localization within desmosomes is required. Our data outline a crucial role of Dp for both desmosomal molecule clustering and mature desmosome formation and provide novel insights into the regulation of intercellular adhesion.

scholarly journals Low Energy Optical Excitations as an Indicator of Structural Changes Initiated at the Termini of Amyloid Proteins

2018 ◽  
Author(s):  
KwangHyok Jong ◽  
Yavar T. Azar ◽  
Luca Grisanti ◽  
Amberley D. Stephens ◽  
Saul T.E. Jones ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Optical Properties ◽  
Amino Acid ◽  
Optical Absorption ◽  
Structural Changes ◽  
Low Energy ◽  
Force Microscopy ◽  
Atomic Force ◽  
N Terminus

<div>We combine absorption and fluorscence spectroscopy experiments and theoretical modeling to specifically examine the role of termini interactions on the optical properties.</div><div><div>Optical absorption and fluorescence is measured for a six-chain amino acid 2Y3J (AIIGLM) which forms a segment of the full amyloid beta 1-40. In order to explore the sensitivity of the optical properties to the termini interactions, the experiments were repeated by acetylating the N-terminus.</div><div>Although atomic force microscopy experiments indicate the formation of some form of fibrilar or crystal aggregates in both systems, the optical properties are strikingly different - acetylation significantly reduces optical activity between 280-350 nm.</div></div>

Unraveling the Role of the rssC Gene of Serratia marcescens by Atomic Force Microscopy

2010 ◽  
Vol 16 (6) ◽  
pp. 755-763 ◽  
Author(s):  
Bor-Ching Sheu ◽  
Chih-Chen Lin ◽  
Ying-Hsien Fu ◽  
Shih-Yuan Lee ◽  
Hsin-Chih Lai ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Serratia Marcescens ◽  
Surface Topography ◽  
Structural Changes ◽  
Fatty Acid Biosynthesis ◽  
Wild Type ◽  
Direct Role ◽  
Force Microscopy ◽  
Atomic Force

AbstractThe product and direct role of the rssC gene of Serratia marcescens is unknown. For unraveling the role of the rssC gene, atomic force microscopy has been used to identify the surfaces of intact S. marcescens wild-type CH-1 cells and rssC mutant CH-1ΔC cells. The detailed surface topographies were directly visualized, and quantitative measurements of the physical properties of the membrane structures were provided. CH-1 and CH-1ΔC cells were observed before and after treatment with lysozyme, and their topography-related parameters, e.g., a valley-to-peak distance, mean height, surface roughness, and surface root-mean-square values, were defined and compared. The data obtained suggest that the cellular surface topography of mutant CH-1ΔC becomes rougher and more precipitous than that of wild-type CH-1 cells. Moreover, it was found that, compared with native wild-type CH-1, the cellular surface topography of lysozyme-treated CH-1 was not changed profoundly. The product of the rssC gene is thus predicted to be mainly responsible for fatty-acid biosynthesis of the S. marcescens outer membrane. This study represents the first direct observation of the structural changes in membranes of bacterial mutant cells and offers a new prospect for predicting gene expression in bacterial cells.

scholarly journals Enhanced Pervaporation Properties of PVA-Based Membranes Modified with Polyelectrolytes. Application to IPA Dehydration

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 14 ◽  
Author(s):  
Mariia Dmitrenko ◽  
Anna Kuzminova ◽  
Andrey Zolotarev ◽  
Sergey Ermakov ◽  
Denis Roizard ◽  
...  
Keyword(s):  
High Performance ◽  
Physicochemical Characteristics ◽  
Contact Angles ◽  
Porous Substrate ◽  
Force Microscopy ◽  
Supported Membrane ◽  
X Ray Scattering ◽  
Atomic Force ◽  
The Impact

In this work, dense and supported pervaporation polyvinyl alcohol (PVA)-based membranes modified with poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate)(PSS)/PAH top nanolayers were synthesized. Two main points were investigated: the role of the polyelectrolyte PAH on water selectivity of the selective polymer matrix and the impact of the porous substrate based on polyacrylonitrile (PAN) and aromatic polysulfone amide (UPM-20®), used to get supported high-performance membranes. Various methods of analysis (fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), porosity, contact angles, ultrafiltration) were applied to study the developed membranes. Transport characteristics of the developed membranes were studied in isopropanol dehydration by pervaporation. Obtained results are discussed in the light of the structure and physicochemical characteristics of these PVA/PAH membranes and the types of porous substrate. It was shown that the PAN-supported membrane with the selective layer based on PVA/PAH modified by 10 polyelectrolyte PSS/PAH bilayers possessed ~4.5 times higher permeation flux with the same high selectivity level (99.9 wt % water in the permeate) for the dehydration of the isopropanol (20 wt % water) at 60 °C compared to the commercial analog PERVAPTM 1201.

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.

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.

Transnationality in the XXI century. Concept and indicators

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Grazia Ietto-Gillies
Keyword(s):  
Structural Changes ◽  
Transnational Corporation ◽  
First Century ◽  
Future Research ◽  
Content Type ◽  
Low Degree ◽  
Fixed Assets ◽  
Inclusive Concept ◽  
The Impact

Purpose The purpose of this paper is to analyse the impact of major structural changes on the conceptualization of the transnational corporation (TNC) based on foreign direct investment (FDI) and on indicators of transnationality. Design/methodology/approach Analysis of three major structural changes which impact the current conception of transnationality. They are: the rise of digital companies; the increased role of finance in the economy; externalization of activities via non-equity modalities (NEMs) with an impact on FDI and on the labour market. Findings The paper finds that the current concept of transnationality needs widening to take account of companies with a low degree of fixed assets abroad such as the digital and the financial companies and those internationalizing via NEMs, as well as to take account of the evolving relationship between TNCs and labour. Research limitations/implications Future research along the lines proposed should consider: working explicitly with the new, inclusive concept of transnationality and arrive at an empirical estimate of the proposed indices of transnationality which modify and amplify the current United Nations Conference on Trade and Development indices. Social implications Useful for understanding the nature of transnationality in the twenty-first century and for developing policies. Originality/value The paper proposes a new concept of transnationality and of the TNC, one that allows for new ways of organizing direct business activities abroad. It also proposes broadening the list of indicators of transnationality.

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