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1.
Sci Rep ; 11(1): 15429, 2021 07 29.
Article in English | MEDLINE | ID: covidwho-1333985

ABSTRACT

Evidences are escalating on the diverse neurological-disorders and asymptomatic cardiovascular-diseases associated with COVID-19 pandemic due to the Sanal-flow-choking. Herein, we established the proof of the concept of nanoscale Sanal-flow-choking in real-world fluid-flow systems using a closed-form-analytical-model. This mathematical-model is capable of predicting exactly the 3D-boundary-layer-blockage factor of nanoscale diabatic-fluid-flow systems (flow involves the transfer of heat) at the Sanal-flow-choking condition. As the pressure of the diabatic nanofluid and/or non-continuum-flows rises, average-mean-free-path diminishes and thus, the Knudsen-number lowers heading to a zero-slip wall-boundary condition with the compressible-viscous-flow regime in the nanoscale-tubes leading to Sanal-flow-choking due to the sonic-fluid-throat effect. At the Sanal-flow-choking condition the total-to-static pressure ratio (ie., systolic-to-diastolic pressure ratio) is a unique function of the heat-capacity-ratio of the real-world flows. The innovation of the nanoscale Sanal-flow-choking model is established herein through the entropy relation, as it satisfies all the conservation-laws of nature. The physical insight of the boundary-layer-blockage persuaded nanoscale Sanal-flow-choking in diabatic flows presented in this article sheds light on finding solutions to numerous unresolved scientific problems in physical, chemical and biological sciences carried forward over the centuries because the mathematical-model describing the phenomenon of Sanal-flow-choking is a unique scientific-language of the real-world-fluid flows. The 3D-boundary-layer-blockage factors presented herein for various gases are universal-benchmark-data for performing high-fidelity in silico, in vitro and in vivo experiments in nanotubes.


Subject(s)
Fluid Shifts/physiology , Models, Theoretical , Nanotubes/chemistry , Rheology/methods , Algorithms , Biophysical Phenomena , COVID-19/physiopathology , Cardiovascular Physiological Phenomena , Cardiovascular System/physiopathology , Computational Biology/methods , Humans , Hydrodynamics , Physical Phenomena , SARS-CoV-2/isolation & purification
2.
Inorg Chem ; 60(9): 6585-6599, 2021 May 03.
Article in English | MEDLINE | ID: covidwho-1195597

ABSTRACT

Silver vanadate nanorods (ß-AgVO3) with silver nanoparticles (Ag-NPs) decorated on the surface of the rods were synthesized by using simple hydrothermal technique and later anchored onto nitrogen-doped reduced graphene oxide (N-rGO) to make a novel nanocomposite. Experimental analyses were carried out to identify the electronic configuration by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis, which revealed monoclinic patterns of the C12/m1 space group with Wulff construction forming beta silver vanadate (ß-AgVO3) crystals with optical density and phase transformations. Ag nucleation showed consistent results with metallic formation and electronic changes occurring in [AgO5] and [AgO3] clusters. Transmission electron microscopy and field-emission scanning electron microscopy with elemental mapping and EDX analysis of the morphology reveals the nanorod structure for ß-AgVO3 with AgNPs on the surface and sheets for N-rGO. Additionally, a novel electrochemical sensor is constructed by using Ag/AgVO3/N-rGO on screen-printed carbon paste electrodes for the detection of antiviral drug levofloxacin (LEV) which is used as a primary antibiotic in controlling COVID-19. Using differential pulse voltammetry, LEV is determined with a low detection limit of 0.00792 nm for a linear range of 0.09-671 µM with an ultrahigh sensitivity of 152.19 µA µM-1 cm-2. Furthermore, modified electrode performance is tested by real-time monitoring using biological and river samples.


Subject(s)
Dielectric Spectroscopy/instrumentation , Dielectric Spectroscopy/methods , Levofloxacin/analysis , Nanocomposites/chemistry , Antiviral Agents/analysis , Antiviral Agents/blood , Antiviral Agents/urine , Carbon/chemistry , Electrodes , Graphite/chemistry , Humans , Levofloxacin/blood , Levofloxacin/urine , Limit of Detection , Metal Nanoparticles/chemistry , Microscopy, Electron, Transmission , Nanotubes/chemistry , Photoelectron Spectroscopy , Silver/chemistry , Silver Compounds/chemistry , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Tablets , Vanadates/chemistry , X-Ray Diffraction
3.
ACS Appl Mater Interfaces ; 13(4): 5678-5690, 2021 Feb 03.
Article in English | MEDLINE | ID: covidwho-1065790

ABSTRACT

The COVID-19 pandemic has clearly shown the importance of developments in fabrication of advanced protective equipment. This study investigates the potential of using multifunctional electrospun poly(methyl methacrylate) (PMMA) nanofibers decorated with ZnO nanorods and Ag nanoparticles (PMMA/ZnO-Ag NFs) in protective mats. Herein, the PMMA/ZnO-Ag NFs with an average diameter of 450 nm were simply prepared on a nonwoven fabric by directly electrospinning from solutions containing PMMA, ZnO nanorods, and Ag nanoparticles. The novel material showed high performance with four functionalities (i) antibacterial agent for killing of Gram-negative and Gram-positive bacteria, (ii) antiviral agent for inhibition of corona and influenza viruses, (iii) photocatalyst for degradation of organic pollutants, enabling a self-cleaning protective mat, and (iv) reusable surface-enhanced Raman scattering substrate for quantitative analysis of trace pollutants on the nanofiber. This multi-functional material has high potential for use in protective clothing applications by providing passive and active protection pathways together with sensing capabilities.


Subject(s)
Anti-Infective Agents/chemistry , Metal Nanoparticles/chemistry , Silver/chemistry , Zinc Oxide/chemistry , Anti-Bacterial Agents/chemistry , Antiviral Agents/chemistry , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Nanofibers/chemistry , Nanotubes/chemistry , Polymethyl Methacrylate/chemistry , Spectrum Analysis, Raman
4.
Sensors (Basel) ; 20(20)2020 Oct 17.
Article in English | MEDLINE | ID: covidwho-890401

ABSTRACT

The COronaVIrus Disease (COVID-19) is a newly emerging viral disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Rapid increase in the number of COVID-19 cases worldwide led the WHO to declare a pandemic within a few months after the first case of infection. Due to the lack of a prophylactic measure to control the virus infection and spread, early diagnosis and quarantining of infected as well as the asymptomatic individuals are necessary for the containment of this pandemic. However, the current methods for SARS-CoV-2 diagnosis are expensive and time consuming, although some promising and inexpensive technologies are becoming available for emergency use. In this work, we report the synthesis of a cheap, yet highly sensitive, cobalt-functionalized TiO2 nanotubes (Co-TNTs)-based electrochemical sensor for rapid detection of SARS-CoV-2 through sensing the spike (receptor binding domain (RBD)) present on the surface of the virus. A simple, low-cost, and one-step electrochemical anodization route was used for synthesizing TNTs, followed by an incipient wetting method for cobalt functionalization of the TNTs platform, which was connected to a potentiostat for data collection. This sensor specifically detected the S-RBD protein of SARS-CoV-2 even at very low concentration (range of 14 to 1400 nM (nano molar)). Additionally, our sensor showed a linear response in the detection of viral protein over the concentration range. Thus, our Co-TNT sensor is highly effective in detecting SARS-CoV-2 S-RBD protein in approximately 30 s, which can be explored for developing a point of care diagnostics for rapid detection of SARS-CoV-2 in nasal secretions and saliva samples.


Subject(s)
Betacoronavirus/metabolism , Biosensing Techniques/methods , Nanotubes/chemistry , Spike Glycoprotein, Coronavirus/analysis , Titanium/chemistry , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Electrochemical Techniques , Humans , Limit of Detection , Pandemics , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , Point-of-Care Systems , Protein Domains , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
5.
Bioconjug Chem ; 31(11): 2553-2563, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-872629

ABSTRACT

As a large enveloped RNA virus, coronavirus is of considerable medical and veterinary significance, and anticoronavirus treatment is challenging due to its biodiversity and rapid variability. In this study, Au@Ag nanorods (Au@AgNRs) were successfully synthesized by coating AuNRs with silver and were shown for the first time to have activity against the replication of porcine epidemic diarrhea virus (PEDV). Viral titer analysis demonstrated that Au@AgNRs could inhibit PEDV infection by 4 orders of magnitude at 12 h post-infection, which was verified by viral protein expression analysis. The potential mechanism of action showed that Au@AgNRs could inhibit the entry of PEDV and decrease the mitochondrial membrane potential and caspase-3 activity. Additionally, we demonstrated that a large amount of virus proliferation can cause the generation of reactive oxygen species in cells, and the released Ag+ and exposed AuNRs by Au@AgNRs after the stimulation of reactive oxygen species has superior antiviral activity to ensure long-term inhibition of the PEDV replication cycle. The integrated results support that Au@AgNRs can serve as a potential therapeutic strategy to prevent the replication of coronavirus.


Subject(s)
Gold/chemistry , Gold/pharmacology , Metal Nanoparticles/chemistry , Porcine epidemic diarrhea virus/drug effects , Porcine epidemic diarrhea virus/physiology , Silver/chemistry , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/toxicity , Chlorocebus aethiops , Dose-Response Relationship, Drug , Gold/toxicity , Nanotubes/chemistry , Vero Cells
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