scholarly journals SARS-CoV-2 Disinfection of Air and Surface Contamination by TiO2 Photocatalyst-Mediated Damage to Viral Morphology, RNA, and Protein

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 942
Author(s):  
Ryosuke Matsuura ◽  
Chieh-Wen Lo ◽  
Satoshi Wada ◽  
Junichi Somei ◽  
Heihachiro Ochiai ◽  
...  
Keyword(s):  
Particle Surface ◽  
Chemical Compounds ◽  
Photocatalytic Reaction ◽  
Dependent Manner ◽  
Tio2 Photocatalyst ◽  
Global Pandemic ◽  
Transmission Electron ◽  
Ultraviolet C ◽  
Human Habitation ◽  
Environmental Disinfection

SARS-CoV-2 is the causative agent of COVID-19, which is a global pandemic. SARS-CoV-2 is transmitted rapidly via contaminated surfaces and aerosols, emphasizing the importance of environmental disinfection to block the spread of virus. Ultraviolet C radiation and chemical compounds are effective for SARS-CoV-2 disinfection, but can only be applied in the absence of humans due to their toxicities. Therefore, development of disinfectants that can be applied in working spaces without evacuating people is needed. Here we showed that TiO2-mediated photocatalytic reaction inactivates SARS-CoV-2 in a time-dependent manner and decreases its infectivity by 99.9% after 20 min and 120 min of treatment in aerosol and liquid, respectively. The mechanistic effects of TiO2 photocatalyst on SARS-CoV-2 virion included decreased total observed virion count, increased virion size, and reduced particle surface spike structure, as determined by transmission electron microscopy. Damage to viral proteins and genome was further confirmed by western blotting and RT-qPCR, respectively. The multi-antiviral effects of TiO2-mediated photocatalytic reaction implies universal disinfection potential for different infectious agents. Notably, TiO2 has no adverse effects on human health, and therefore, TiO2-induced photocatalytic reaction is suitable for disinfection of SARS-CoV-2 and other emerging infectious disease-causing agents in human habitation.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

scholarly journals Antitumor Potential of Green Synthesized ZnONPs Using Root Extract of Withania somnifera against Human Breast Cancer Cell Line

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Kollur Shiva Prasad ◽  
Shashanka K Prasad ◽  
Ravindra Veerapur ◽  
Ghada Lamraoui ◽  
Ashwini Prasad ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Line ◽  
Withania Somnifera ◽  
Root Extract ◽  
Dependent Manner ◽  
Sem Images ◽  
Xrd Pattern ◽  
Transmission Electron

Herein we report the synthesis of zinc oxide nanoparticles (ZnONPs) using Withania somnifera root extract (WSE) as an effective chelating agent. The microscopic techniques viz., X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) were employed to analyze the as-obtained ZnONPs. The crystalline planes observed from the XRD pattern agrees with the hexagonal wurtzite structure of the as-prepared ZnONPs. The aggregations and agglomerations observed in the SEM images indicated that the size of the as-prepared ZnONPs was between 30 and 43 nm. The interplanar distance between the lattice fringes observed in the HRTEM image was found to be 0.253 nm, which is in good agreement with the (100) plane obtained in the XRD pattern. Furthermore, the anti-breast cancer cytotoxic evaluation was carried out using the MCF-7 cell line, and the results showed significant cytotoxic effects in a dose-dependent manner.

scholarly journals Synthesis, Characterization, and Optimization of Green Silver Nanoparticles Using Neopestalotiopsis clavispora and Evaluation of Its Antibacterial, Antibiofilm, and Genotoxic Effects

2021 ◽  
Vol 5 (3) ◽  
pp. 109-122
Author(s):  
Tuğba Kahraman ◽  
Safiye Elif Korcan ◽  
Recep Liman ◽  
İbrahim Hakkı Ciğerci ◽  
Yaser Acikbas ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Nuclear Ribosomal Dna ◽  
Diffusion Method ◽  
Dependent Manner ◽  
Transmission Electron ◽  
Infrared Spectrophotometer ◽  
Average Size ◽  
Novel Applications ◽  
Dose Dependent

Abstract Silver nanoparticles (AgNPs) have been used in a variety of biomedical applications in the last two decades, including antimicrobial, anti-inflammatory, and anticancer treatments. The present study highlights the extracellular synthesis of silver nanoparticles AgNPs using Neopestalotiopsis clavispora MH244410.1 and its antibacterial, antibiofilm, and genotoxic properties. Locally isolated N. clavispora MH244410.1 was identified by Internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA. Optimization of synthesized AgNPs was performed by using various parameters (pH (2, 4, 7, 9 and 12), temperature (25, 35 and 45 °C), and substrate concentration (0.05, 0.1, 0.15, 0.2 and 0.25 mM)). After 72 hours of incubation in dark conditions, the best condition for the biosynthesis of AgNPs was determined as 0.25 mM metal concentration at pH 12 and 35 °C. Fungal synthesized AgNPs were characterized via spectroscopic and microscopic techniques such as Fouirer Transform Infrared Spectrophotometer (FTIR), UV-Visible Spectroscopy, and Transmission Electron Microscopy (TEM). The average size of the AgNPs was determined less than 60 nm using the TEM and Zetasizer measurement system (measured in purity water suspension). The characteristic peak of AgNPs was observed at ~414 nm from UV-Vis results. Antibacterial and genotoxic activity of synthesized AgNPs (0.1, 1, and 10 ppm) were also determined by using the agar well diffusion method and in vivo Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster. AgNPs exhibited potential antimicrobial activity against all the tested bacteria (Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa) except Escherichia coli in a dose-dependent manner. AgNPs did not induce genotoxicity in the Drosophila SMART assay. 79.33, 65.47, and 41.95% inhibition of biofilms formed by P. aeruginosa were observed at 10, 1, and 0.1 ppm of AgNPs, respectively. The overall results indicate that N. clavispora MH244410.1 is a good candidate for novel applications in biomedical research.

scholarly journals Arachidonic acid promotes the binding of 5-lipoxygenase on nanodiscs containing 5-lipoxygenase activating protein in the absence of calcium-ions

2020 ◽  
Author(s):  
Ramakrishnan B. Kumar ◽  
Pasi Purhonen ◽  
Hans Hebert ◽  
Caroline Jegerschöld
Keyword(s):  
Arachidonic Acid ◽  
Complex Formation ◽  
Calcium Ions ◽  
Dependent Manner ◽  
Present Communication ◽  
Nuclear Membranes ◽  
His Tag ◽  
C Terminus ◽  
Transmission Electron

AbstractAmong the first steps in inflammation is the conversion of arachidonic acid (AA) stored in the cell membranes into leukotrienes. This occurs mainly in leukocytes and depends on the interaction of two proteins: 5-lipoxygenase (5LO), stored away from the nuclear membranes until use and 5-lipoxygenase activating protein (FLAP), a transmembrane, homotrimeric protein, constitutively present in nuclear membrane. We could earlier visualize the binding of 5LO to nanodiscs in the presence of Ca2+-ions by the use of transmission electron microscopy (TEM) on samples negatively stained by sodium phosphotungstate. In the absence of Ca2+-ions 5LO did not bind to the membrane. In the present communication, FLAP reconstituted in the nanodiscs which could be purified if the His-tag was located on the FLAP C-terminus but not the N-terminus. Our aim was to find out if 1) 5LO would bind in a Ca2+-dependent manner also when FLAP is present? 2) Would the substrate (AA) have effects on 5LO binding to FLAP-nanodiscs? TEM was used to assess the complex formation between 5LO and FLAP-nanodiscs along with, sucrose gradient purification, gel-electrophoresis and mass spectroscopy. It was found that presence of AA by itself induces complex formation in the absence of added calcium. This finding corroborates that AA is necessary for the complex formation and that a Ca2+-flush is mainly needed for the recruitment of 5LO to the membrane. Our results also showed that the addition of Ca2+-ions promoted binding of 5LO on the FLAP-nanodiscs as was also the case for nanodiscs without FLAP incorporated. In the absence of added substances no 5LO-FLAP complex was formed. Another finding is that the formation of a 5LO-FLAP complex appears to induce fragmentation of 5LO in vitro.

scholarly journals Gastric Cancer Extracellular Vesicles Tune the Migration and Invasion of Epithelial and Mesenchymal Cells in a Histotype-Dependent Manner

2019 ◽  
Vol 20 (11) ◽  
pp. 2608 ◽  
Author(s):  
Sara Rocha ◽  
Sara Pinto Teles ◽  
Mafalda Azevedo ◽  
Patrícia Oliveira ◽  
Joana Carvalho ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Flow Cytometry ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Extracellular Vesicles ◽  
Mesenchymal Cells ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
Diffuse Type ◽  
Transmission Electron

Extracellular vesicles (EVs) secreted by tumor cells modulate recipient cells’ behavior, but their effects in normal cells from the tumor microenvironment remain poorly known. In this study, we dissected the functional impact of gastric cancer cell-derived EVs (GC-EVs), representative of distinct GC histotypes, on the behavior of normal isogenic epithelial and mesenchymal cells. GC-EVs were isolated by differential centrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis, and imaging flow-cytometry. Epithelial and mesenchymal cells were challenged with GC-EVs and submitted to proliferation, migration, and invasion assays. Expression of epithelial and mesenchymal markers was followed by immunofluorescence and flow-cytometry. Our results indicated that GC-EVs secreted by diffuse-type cancer cells decrease the migration of recipient cells. This effect was more prominent and persistent for mesenchymal recipient cells, which also increased Fibronectin expression in response to EVs. GC-EVs secreted by cancer cells derived from tumors with an intestinal component increased invasion of recipient epithelial cells, without changes in EMT markers. In summary, this study demonstrated that GC-EVs modulate the migration and invasion of epithelial and mesenchymal cells from the tumor microenvironment, in a histotype-dependent manner, highlighting new features of intestinal and diffuse-type GC cells, which may help explaining differential metastasis patterns and aggressiveness of GC histotypes.

scholarly journals Visible Light Photocatalytic Activity of Thin Film Coated on Polycarbonate Surface with N- and Ni-Codoped TiO2 Photocatalyst

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1237
Author(s):  
Byung-Geon Park ◽  
Chang-Ho Lee ◽  
Kyong-Hwan Chung
Keyword(s):  
Thin Film ◽  
Visible Light ◽  
Pathogenic Bacteria ◽  
Sol Gel ◽  
Photocatalytic Reaction ◽  
Tio2 Photocatalyst ◽  
E Coli ◽  
Amorphous Tio2 ◽  
Visible Light Photocatalytic ◽  
Decomposition Properties

N- and Ni-coated TiO2 (NNT) were prepared by a facile sol-gel method as a photosensitive photocatalyst to visible light. NNT sol was used to coat the surface of an LED lamp cap and body made of polycarbonate with a thin NNT film. The coated thin film was dried in an oven at 130 °C. This NNT thin film had an amorphous TiO2 structure and absorbed 600 nm of visible light. The decomposition properties of formaldehyde on the NNT photocatalyst after irradiation with visible light were investigated. The LED lamp was irradiated with visible light at 500–620 nm and 6 W. Formaldehyde was decomposed by a photocatalytic reaction by visible light irradiation on the NNT-coated polycarbonate surface. Escherichia coli (E. coli), Staphylococcus aureus, and Pseudomonas aeruginosa were also used to examine the sterilizing properties of pathogenic bacteria using an LED lamp kit. The pathogenic bacteria on the NNT-coated polycarbonate surface were sterilized by irradiation with visible light.

scholarly journals Second Life Application of Automotive Catalysts: Hydrodynamic Cavitation Recovery and Photo Water Splitting

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1307 ◽  
Author(s):  
Adrian Ciocanea ◽  
Eugeniu Vasile ◽  
Viorel Ionescu ◽  
Florentina Iuliana Maxim ◽  
Cornelia Diac ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Second Life ◽  
Anatase Phase ◽  
Particle Surface ◽  
Hydrodynamic Cavitation ◽  
Cubic Phase ◽  
Shear Stresses ◽  
Automotive Catalysts ◽  
Transmission Electron

A hydrodynamic cavitation method was used to maximize the effect of destructuration of a honeycomb monolithic support of a spent Selective Catalyst Reduction (SCR) catalyst—V2O5-WO3/TiO2-type—for extracting crystalline titanium and tungsten oxides from the cordierite surface. A high relative inlet pressure of 40 MPa was applied to a divergent nozzle for obtaining high shear stresses of the submerged cavitating jets and intensive micro- and nano-jets and shock waves acting on the particle surface of the milled catalyst. Scanning Electron Microscopy (SEM) analysis indicated the compact morphology of the thin metal oxide layer at the surface of the cordierite support and the high content of Ti and W elements in the sample. Energy dispersive spectroscopy (EDAX) performed along with TEM investigations on different nano-zones from the sample established the elemental composition of WO3-TiO2 agglomerates separated after hydrodynamic cavitation processing and identified as independent nanocrystalline structures through Bright Field Transmission Electron Microscopy (BF-TEM) and High Resolution Transmission Electron Microscopy (HR-TEM) measurements. The tetragonal anatase phase of TiO2 and cubic phase of WO3 were established by both interplanar d spacing measurements and X-ray diffraction analysis. The photoelectrochemical results showed the possible second life application of automotive catalysts.

scholarly journals Inhibitory effect of gamma irradiation against Cucumber green mottle mosaic virus

2017 ◽  
Vol 53 (No. 4) ◽  
pp. 201-207 ◽  
Author(s):  
Hong Jin-Sung ◽  
Jeong Mi-Ae ◽  
Jeong Rae-Dong
Keyword(s):  
Gamma Irradiation ◽  
Mosaic Virus ◽  
Fungal Pathogens ◽  
Inhibitory Effect ◽  
Plant Viruses ◽  
Dependent Manner ◽  
Genomic Rna ◽  
Transmission Electron ◽  
Virion Structure ◽  
Dose Dependent

Gamma irradiation has been shown to be an effective method of controlling plant bacterial and fungal pathogens, but data on its effect against plant viruses is limited. A mechanism for the inactivation of plant viruses by gamma irradiation has not been proposed. Gamma irradiation was evaluated for the inactivation of Cucumber green mottle mosaic virus (CGMMV) in Nicotiana tabacum plants. CGMMV infectivity decreased gradually in a dose-dependent manner, and the virus was completely inactivated at over 40 kGy. Transmission electron microscopy revealed that gamma irradiation disrupts the virion structure and degrades viral protein and genomic RNA, suggesting that damage to viral constituents is the mechanism by which gamma irradiation inactivates the virus.

Vapor phase synthesis of Al-doped titania powders

1994 ◽  
Vol 9 (5) ◽  
pp. 1241-1249 ◽  
Author(s):  
Kamal M. Akhtar ◽  
Sotiris E. Pratsinis ◽  
Sebastian V.R. Mastrangelo
Keyword(s):  
Vapor Phase ◽  
Flow Reactor ◽  
Particle Surface ◽  
Particle Morphology ◽  
High Concentration ◽  
Phase Synthesis ◽  
Transmission Electron ◽  
Significant Enrichment ◽  
Vapor Phase Synthesis ◽  
Doped Titania

The role of aluminum as dopant in gas phase synthesis of titania powders was experimentally investigated in an aerosol flow reactor between 1300 and 1700 K. Titania was produced by vapor phase oxidation of titanium tetrachloride in the presence of dopant aluminum trichloride vapor. The presence of aluminum altered the particle morphology from polyhedral to irregular crystals. Energy dispersive analysis and transmission electron microscopy indicated that the powders were mixtures of crystalline titania and amorphous alumina. Analysis by XPS indicated significant enrichment of aluminum on the particle surface. Some aluminum titanate (up to 17% by volume) was formed at 1700 K when a high concentration of AlCl3 was used (AlCl3/TiCl4 ≥ 0.07). Measurements of lattice parameters by x-ray diffraction indicated that aluminum formed a solid solution in titania. While titania synthesized in the absence of aluminum was about 90% anatase, the introduction of aluminum resulted in pure rutile at AlCl3/TiCl4 = 0.07. The effects of aluminum on titania phase composition and morphology are explained by the creation of oxygen vacancies in the titania crystallites and by the enhancement of the sintring rate of titania grains.

scholarly journals Salicylic acid-mediated plasmodesmal closure via Remorin-dependent lipid organization

2019 ◽  
Vol 116 (42) ◽  
pp. 21274-21284 ◽  
Author(s):  
Dingquan Huang ◽  
Yanbiao Sun ◽  
Zhiming Ma ◽  
Meiyu Ke ◽  
Yong Cui ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Lipid Raft ◽  
Plant Pathogens ◽  
Regulatory Protein ◽  
Cell Communication ◽  
Direct Interaction ◽  
Membrane Lipid ◽  
Dependent Manner ◽  
Transmission Electron ◽  
Lipid Organization

Plasmodesmata (PD) are plant-specific membrane-lined channels that create cytoplasmic and membrane continuities between adjacent cells, thereby facilitating cell–cell communication and virus movement. Plant cells have evolved diverse mechanisms to regulate PD plasticity in response to numerous environmental stimuli. In particular, during defense against plant pathogens, the defense hormone, salicylic acid (SA), plays a crucial role in the regulation of PD permeability in a callose-dependent manner. Here, we uncover a mechanism by which plants restrict the spreading of virus and PD cargoes using SA signaling by increasing lipid order and closure of PD. We showed that exogenous SA application triggered the compartmentalization of lipid raft nanodomains through a modulation of the lipid raft-regulatory protein, Remorin (REM). Genetic studies, superresolution imaging, and transmission electron microscopy observation together demonstrated that Arabidopsis REM1.2 and REM1.3 are crucial for plasma membrane nanodomain assembly to control PD aperture and functionality. In addition, we also found that a 14-3-3 epsilon protein modulates REM clustering and membrane nanodomain compartmentalization through its direct interaction with REM proteins. This study unveils a molecular mechanism by which the key plant defense hormone, SA, triggers membrane lipid nanodomain reorganization, thereby regulating PD closure to impede virus spreading.

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