scholarly journals Magneto-Optical Nanostructures for Viral Sensing

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1271 ◽  
Author(s):  
Sabine Szunerits ◽  
Tamazouzt Nait Saada ◽  
Dalila Meziane ◽  
Rabah Boukherroub
Keyword(s):  
Viral Infections ◽  
Signal To Noise Ratio ◽  
Viral Disease ◽  
Magnetic Bead ◽  
Superparamagnetic Nanoparticles ◽  
Plasmonic Nanostructures ◽  
Complex Matrix ◽  
Severe Respiratory Distress ◽  
Sensing Applications ◽  
Optical Nanostructures

The eradication of viral infections is an ongoing challenge in the medical field, as currently evidenced with the newly emerged Coronavirus disease 2019 (COVID-19) associated with severe respiratory distress. As treatments are often not available, early detection of an eventual infection and its level becomes of outmost importance. Nanomaterials and nanotechnological approaches are increasingly used in the field of viral sensing to address issues related to signal-to-noise ratio, limiting the sensitivity of the sensor. Superparamagnetic nanoparticles (MPs) present one of the most exciting prospects for magnetic bead-based viral aggregation assays and their integration into different biosensing strategies as they can be easily separated from a complex matrix containing the virus through the application of an external magnetic field. Despite the enormous potential of MPs as capture/pre-concentrating elements, they are not ideal with regard of being active elements in sensing applications as they are not the sensor element itself. Even though engineering of magneto-plasmonic nanostructures as promising hybrid materials directly applicable for sensing due to their plasmonic properties are often used in sensing, to our surprise, the literature of magneto-plasmonic nanostructures for viral sensing is limited to some examples. Considering the wide interest this topic is evoking at present, the different approaches will be discussed in more detail and put into wider perspectives for sensing of viral disease markers.

The Diagnosis of Viral Disease by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 270-273
Author(s):  
William B. McCombs ◽  
Cameron E. McCoy
Keyword(s):  
Electron Microscopy ◽  
Hospital Stay ◽  
Viral Infections ◽  
Medical Profession ◽  
Bacterial Pathogens ◽  
Viral Disease ◽  
Viral Pathogens ◽  
Academic Interest ◽  
The Past

Recent years have brought a reversal in the attitude of the medical profession toward the diagnosis of viral infections. Identification of bacterial pathogens was formerly thought to be faster than identification of viral pathogens. Viral identification was dismissed as being of academic interest or for confirming the presence of an epidemic, because the patient would recover or die before this could be accomplished. In the past 10 years, the goal of virologists has been to present the clinician with a viral identification in a matter of hours. This fast diagnosis has the potential for shortening the patient's hospital stay and preventing the administering of toxic and/or expensive antibiotics of no benefit to the patient.

scholarly journals Innate Immunity in Children and the Role of ACE2 Expression in SARS-CoV-2 Infection

2021 ◽  
Vol 13 (3) ◽  
pp. 363-382
Author(s):  
Mario Dioguardi ◽  
Angela Pia Cazzolla ◽  
Claudia Arena ◽  
Diego Sovereto ◽  
Giorgia Apollonia Caloro ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Viral Infections ◽  
Respiratory Infections ◽  
Viral Disease ◽  
Receptor Expression ◽  
Virus Infections ◽  
Search Terms ◽  
Bibliographic Search ◽  
Meta Analyses

COVID-19 (Coronavirus Disease 2019) is an emerging viral disease caused by the coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which leads to severe respiratory infections in humans. The first reports came in December 2019 from the city of Wuhan in the province of Hubei in China. It was immediately clear that children developed a milder disease than adults. The reasons for the milder course of the disease were attributed to several factors: innate immunity, difference in ACE2 (angiotensin-converting enzyme II) receptor expression, and previous infections with other common coronaviruses (CovH). This literature review aims to summarize aspects of innate immunity by focusing on the role of ACE2 expression and viral infections in children in modulating the antibody response to SARS-CoV-2 infection. This review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles deemed potentially eligible were considered, including those dealing with COVID-19 in children and providing more up-to-date and significant data in terms of epidemiology, prognosis, course, and symptoms, focusing on the etiopathogenesis of SARS-CoV-2 disease in children. The bibliographic search was conducted using the search engines PubMed and Scopus. The following search terms were entered in PubMed and Scopus: COVID-19 AND ACE2 AND Children; COVID-19 AND Immunity innate AND children. The search identified 857 records, and 18 studies were applicable based on inclusion and exclusion criteria that addressed the issues of COVID-19 concerning the role of ACE2 expression in children. The scientific literature agrees that children develop milder COVID-19 disease than adults. Milder symptomatology could be attributed to innate immunity or previous CovH virus infections, while it is not yet fully understood how the differential expression of ACE2 in children could contribute to milder disease.

Parametrically Excited Electrostatic MEMS Cantilever Beam With Flexible Support

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mark Pallay ◽  
Shahrzad Towfighian
Keyword(s):  
Cantilever Beam ◽  
Large Amplitude ◽  
Chaotic Behavior ◽  
Signal To Noise Ratio ◽  
Mass Sensors ◽  
Flexible Support ◽  
Sensing Applications ◽  
Electrostatic Mems ◽  
Fringe Fields ◽  
Steady State Amplitude

Parametric resonators that show large amplitude of vibration are highly desired for sensing applications. In this paper, a microelectromechanical system (MEMS) parametric resonator with a flexible support that uses electrostatic fringe fields to achieve resonance is introduced. The resonator shows a 50% increase in amplitude and a 50% decrease in threshold voltage compared with a fixed support cantilever model. The use of electrostatic fringe fields eliminates the risk of pull-in and allows for high amplitudes of vibration. We studied the effect of decreasing boundary stiffness on steady-state amplitude and found that below a threshold chaotic behavior can occur, which was verified by the information dimension of 0.59 and Poincaré maps. Hence, to achieve a large amplitude parametric resonator, the boundary stiffness should be decreased but should not go below a threshold when the chaotic response will appear. The resonator described in this paper uses a crab-leg spring attached to a cantilever beam to allow for both translation and rotation at the support. The presented study is useful in the design of mass sensors using parametric resonance (PR) to achieve large amplitude and signal-to-noise ratio.

scholarly journals Spectrum Sensing in Cognitive Radio using Frequency Domain

2019 ◽  
Vol 9 (2) ◽  
pp. 3475-3477
Keyword(s):  
Cognitive Radio ◽  
Frequency Domain ◽  
Spectrum Sensing ◽  
Bandwidth Allocation ◽  
Dynamic Spectrum Access ◽  
Signal To Noise Ratio ◽  
Wide Band ◽  
Energy Detection ◽  
Secondary Users ◽  
Sensing Applications

An efficient bandwidth allocation and dynamic bandwidth access away from its previous limits is referred as cognitive radio (CR).The limited spectrum with inefficient usage requires the advances of dynamic spectrum access approach, where the secondary users are authorized to utilize the unused temporary licensed spectrum. For this reason it is essential to analyze the absence/presence of primary users for spectrum usage. So spectrum sensing is the main requirement and developed to sense the absence/ presence of a licensed user. This paper shows the design model of energy detection based spectrum sensing in frequency domain utilizing Binary Symmetric Channel (BSC) ,Additive white real Gaussian channel (AWGN), Rayleigh fading channel users for 16-Quadrature Amplitude Modulation(QAM) which is utilized for the wide band sensing applications at low Signal to noise Ratio(SNR) level to reduce the false error identification. The spectrum sensing techniques has least computational complexity. Simulink model for the energy detection based spectrum sensing using frequency domain in MATLAB 2014a.

scholarly journals Links between exercise/nutrition and antioxidants - protective effects on immune/respiratory systems as defense against viral infections

2020 ◽  
Vol 8 (36) ◽  
pp. 23-31
Author(s):  
Abdurrahman Kharbat ◽  
Stephen Rossettie ◽  
Mimi Zumwalt
Keyword(s):  
Viral Infections ◽  
Viral Disease ◽  
Antioxidant Systems ◽  
Protective Effects ◽  
Enzymatic Antioxidant ◽  
Optimal Dosing ◽  
Open Window ◽  
The Impact ◽  
The Relationship ◽  
Harmful Effects

This paper discusses factors involved in COVID-19 pathophysiology, with a focus on nutrition, exercise, enzymatic antioxidant systems, and the interplay between immune tolerance and resistance. Of all the supplements, zinc has the most evidence for effectiveness against viruses. However, these data were based primarily on studies measuring duration of the common cold rather than on COVID-19, and optimal dosing remains unclear. Exercise has been shown to have protective tolerogenic effects against viral infection due to the impact of extracellular superoxide dismutases (EC-SODs). Exercise may have a combination of beneficial and harmful effects on outright resistance to viruses in the short term, but taken as a whole it likely has a net protective effect on the immune system. The evidence is examined through the lens of the open window theory and a thorough investigation of the relationship between EC-SODs and exercise/diet. By better understanding the host-virus relationship, clinicians and researchers alike can collaborate to establish guiding principles regarding the steps that individuals can take to protect against some of the deleterious effects of viral infections. More research in this area is needed to understand the relationships among exercise, nutrition, and viral disease. Keywords: COVID-19, SARS CoV-2, nutrition, zinc, EC-SODs, superoxide dismutase, exercise, enzymatic antioxidant/immune systems

scholarly journals Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5188
Author(s):  
Tomi Koskinen ◽  
Taneli Juntunen ◽  
Ilkka Tittonen
Keyword(s):  
Signal To Noise Ratio ◽  
Graphene Film ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Large Area ◽  
Sensor Applications ◽  
Thermal Distribution ◽  
Sensing Applications ◽  
Detection Of Objects ◽  
Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

scholarly journals Antiviral Effects of Hydroxychloroquine and Type I Interferon on In Vitro Fatal Feline Coronavirus Infection

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 576 ◽  
Author(s):  
Tomomi Takano ◽  
Kumi Satoh ◽  
Tomoyoshi Doki ◽  
Taishi Tanabe ◽  
Tsutomu Hohdatsu
Keyword(s):  
Viral Infections ◽  
Viral Disease ◽  
High Morbidity ◽  
Type I ◽  
Feline Infectious Peritonitis ◽  
Antiviral Effects ◽  
Immune Mediated ◽  
Coronavirus Infection ◽  
Feline Coronavirus

Feline infectious peritonitis (FIP) is a viral disease with a high morbidity and mortality by the FIP virus (FIPV, virulent feline coronavirus). Several antiviral drugs for FIP have been identified, but many of these are expensive and not available in veterinary medicine. Hydroxychloroquine (HCQ) is a drug approved by several countries to treat malaria and immune-mediated diseases in humans, and its antiviral effects on other viral infections (e.g., SARS-CoV-2, dengue virus) have been confirmed. We investigated whether HCQ in association with interferon-ω (IFN-ω) is effective for FIPV in vitro. A total of 100 μM of HCQ significantly inhibited the replication of types I and II FIPV. Interestingly, the combination of 100 μM of HCQ and 104 U/mL of recombinant feline IFN-ω (rfIFN-ω, veterinary registered drug) increased its antiviral activity against type I FIPV infection. Our study suggested that HCQ and rfIFN-ω are applicable for treatment of FIP. Further clinical studies are needed to verify the combination of HCQ and rIFN-ω will be effective and safe treatment for cats with FIP.

scholarly journals A 77-GHz Six-Port Sensor for Accurate Near-Field Displacement and Doppler Measurements

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2565 ◽  
Author(s):  
Homa Arab ◽  
Steven Dufour ◽  
Emilia Moldovan ◽  
Cevdet Akyel ◽  
Serioja Tatu
Keyword(s):  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Industrial Applications ◽  
High Signal ◽  
Millimetre Wave ◽  
Sensing Applications ◽  
Radar Sensing ◽  
Cw Radar ◽  
77 Ghz

A continuous-wave (CW) radar sensor design based on a millimetre-wave six-port interferometer is proposed. A complete sensor prototype is conceived of, fabricated and measured at 77 GHz for short-range professional and industrial applications. This sensor is designed to measure distances and Doppler frequencies with high accuracy, at a reasonable cost. Accurate phase measurements are also performed using the six-port technology, which makes it a promising candidate for CW radar sensing applications. Advances in the performance and functionality of six-port sensors are surveyed to highlight recent progress in this area. These include improvements in design, low power consumption, high signal to noise ratio, compactness, robustness and simplicity in realization. Given the fact that they are easy to fabricate, due to the lack of active circuits and being highly accurate, it is expected that six-port sensors will significantly contribute to the development of human tracking devices and industrial sensors in the near future. The entire circuit prototype, including the transmitter, the receiver antenna, the six-port interferometer and the four power detectors have been integrated on a die. The circuit is fabricated using a hybrid integrated technology on a 127-μm ceramic substrate with a relative permittivity of εr=9.8. Calibrated tuning forks are used to assess the performance of the six-port sensor experimentally for various frequencies.

scholarly journals Effective and Simple Methods of Preventing the Transmission of Viral Diseases

2020 ◽  
pp. 46-56
Author(s):  
A. Taqaddas
Keyword(s):  
Health Care ◽  
Virus Infection ◽  
Care Setting ◽  
Viral Infections ◽  
Viral Disease ◽  
Therapeutic Strategies ◽  
Viral Transmission ◽  
Viral Diseases ◽  
Policy Makers ◽  
Health Care Settings

Viral infections have always been of major concern in communities, health care settings and medical fields including radiotherapy and Radiology. Recently corona virus infection has attained global attention in the wake of covid-19 outbreak and consequently highlighted importance of viral prevention, diagnostic and therapeutic strategies to control and treat viral disease. In view of the recent events, the author reviewed the current and past literature to discuss contagious versus infectious viral transmission, as well as simple and effective ways of preventing the spread of viral diseases in community and health care setting so that this information can be used for preventing viral transmission at all levels. The article is written for a wide variety of audiences i.e. scientific and medical communities policy makers and general public.

scholarly journals Genome Editing Strategies to Protect Livestock from Viral Infections

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1996
Author(s):  
Jenny-Helena Söllner ◽  
Thomas C. Mettenleiter ◽  
Björn Petersen
Keyword(s):  
Viral Infections ◽  
Disease Outbreaks ◽  
Transgenic Animals ◽  
Viral Disease ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Host Interactions ◽  
Associated Proteins ◽  
Preventive Vaccination ◽  
Control And Eradication

The livestock industry is constantly threatened by viral disease outbreaks, including infections with zoonotic potential. While preventive vaccination is frequently applied, disease control and eradication also depend on strict biosecurity measures. Clustered regularly interspaced palindromic repeats (CRISPR) and associated proteins (Cas) have been repurposed as genome editors to induce targeted double-strand breaks at almost any location in the genome. Thus, CRISPR/Cas genome editors can also be utilized to generate disease-resistant or resilient livestock, develop vaccines, and further understand virus–host interactions. Genes of interest in animals and viruses can be targeted to understand their functions during infection. Furthermore, transgenic animals expressing CRISPR/Cas can be generated to target the viral genome upon infection. Genetically modified livestock can thereby reduce disease outbreaks and decrease zoonotic threats.

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