*Artificial saliva aerosol source and detection system for spreading analysis in indoor environments

In the context of the Corona pandemic the investigation of aerosol spreading is utmost important as the virus is transported by the aerosol particles exhaled by an infected person. Thus, a new aerosol generation and detection system is set up and validated. The system consists of an aerosol source generating a particle size distribution mimicking typical human exhalation with particles sizes between 0.3-2.5 µm and an array of Sensirion SPS30 particulate matter sensors. An accuracy assessment of the SPS30 sensors is conducted using a TSI OPS3330, a high-precision optical particle sizer. Low deviations of ±5 % of the particle concentration measured with the SPS30 with respect to the OPS are reported for concentrations below 2'500/cm3 and +10% for particle densities up to 25'000/cm3. As an application example the system is employed in a short distance single-aisle research aircraft Dornier 728 (Do728) located at DLR Göttingen, to investigate the large-scale aerosol-spreading. With this measurement system spreading distance from an index passenger extending one seat row to the front and two seat rows to the back is determined. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

SARS-CoV-2 structures detection in artificial saliva using ATR-FTIR associated with Linear Discriminant Analysis

Here, we used ATR-FTIR platform supported by artificial intelligence algorithms to identify unique infrared vibrational modes of a pseudotyped human immunodeficiency virus type-1 (HIV-1) coupled to Spike (S) protein of SARS-CoV-2 (HIV/NanoLuc-SARS-CoV-2 pseudotype virus). © Optica Publishing Group 2022 The Authors.

SARS-CoV-2 structures detection in artificial saliva using ATR-FTIR associated with Linear Discriminant Analysis

Here, we used ATR-FTIR platform supported by artificial intelligence algorithms to identify unique infrared vibrational modes of a pseudotyped human immunodeficiency virus type-1 (HIV-1) coupled to Spike (S) protein of SARS-CoV-2 (HIV/NanoLuc-SARS-CoV-2 pseudotype virus). © Optica Publishing Group 2022 The Authors.

Practical tapered optical fiber system for in-situ label-free sensing of various antigens

A practical tapered optical fiber (TOF) biosensing system was developed for label-free detection using antigen-antibody pairs with repeatable results and a very high degree of sensitivity. This was done by attaching molecular recognition agents to a tapered fiber surface for augmenting sensitivity and specificity of analyte. The entire system included three main parts: a tunable laser, a tapered fiber, and an optical detector. Light from an unpolarized tunable fiber laser was introduced into the tapered fiber from one end, and the transmitted intensity was detected by a photodetector. In the tapered fiber area, the evanescent electromagnetic field, which extends outside the fiber, was able to detect minute changes in the refractive index caused by antigen-antibody pairs. Recorded data was analyzed using an innovative Fourier analysis method to find phase changes, which are directly related to the biomolecular concentration coated on fiber, from which antibody-antigen concentrations are obtained. Two experiments were performed to confirm the concept using two very different agents. The first was the protein Interleukin-8 (IL-8). Repeatable results with a sensitivity of 10 pg/mL were achieved. The second was human coronavirus OC43 (HCoV-OC43), a surrogate viral particle for SARS-CoV-2, with a sensitivity of 50 viruses/mL. Critical sources of error were identified and addressed for the purpose of using the device for real clinical diagnosis in various real-life environments, where viruses can reside in water, phosphate-buffer solution, or saliva, the most popular three environments in real clinical diagnosis. Our device was designed according to the principle that only one specific kind of antibody and antigen can be combined together. The device demonstrated good accuracy to chosen analyte(s) tailored to specific applications and offered the potential to develop a point-of-care device used in clinics, as well as for detecting a variety of viruses and biocontaminants. The reproducibility of TOFs was confirmed through multiple fabrications and consistent results. [ FROM AUTHOR] Copyright of Optical Engineering is the property of SPIE - International Society of Optical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Analysis of aerosol spreading in a German Inter City Express (ICE) train carriage

This paper focuses on the propagation of aerosols in a rolling stock passenger compartment. Extensive measurements were carried out in our stationary test vehicle DIRK, an ICE 2 rail car, operated in a climate chamber. It is shown that the propagation of aerosols only occurs for a distance of a few seat rows. Furthermore, the maximum percentage of particles exhaled by a passenger and inhaled by another passenger is less than 0.35%. A mouth-nose-protection (surgical mask) at the aerosol source reduces this value to a maximum of 0.25%. Moreover, the use of a mouth-nose-cover reduced the propagation lengths. Here, only the effect of the mask at the source was considered, a further reduction of inhaled aerosols will be achieved when the receivers also wear masks. It is concluded that, for this type of passenger coach, the indirect propagation of aerosols, i.e., via the HVAC system, is nearly irrelevant compared to the direct propagation from one passenger to another. However, there is a non-zero aerosol transport via the HVAC system, resulting in local inhaled particles far away from the source of around 0.015–0.026%, which is more than one order of magnitude lower than on the most highly contaminated seats.

A Review on Xerostomia and Its Various Management Strategies: The Role of Advanced Polymeric Materials in the Treatment Approaches.

The medical term xerostomia refers to the subjective sensation of oral dryness. The etiology seems to be multifactorial with the most frequently reported causes being the use of xerostomic medications, neck and head radiation, and systematic diseases (such as Sjögren's syndrome). Xerostomia is associated with an increased incidence of dental caries, oral fungal infections, and difficulties in speaking and chewing/swallowing, which ultimately affect the oral health-related quality of life. The development of successful management schemes is regarded as a highly challenging project due to the complexity of saliva. This is why, in spite of the fact that there are therapeutic options aiming to improve salivary function, most management approaches are alleviation-oriented. In any case, polymers are an integral part of the various formulations used in every current treatment approach, especially in the saliva substitutes, due to their function as thickening and lubricating agents or, in the case of mucoadhesive polymers, their ability to prolong the treatment effect. In this context, the present review aims to scrutinize the literature and presents an overview of the role of various polymers (or copolymers) on either already commercially available formulations or novel drug delivery systems currently under research and development.

Label-Free LSPR-Vertical Microcavity Biosensor for On-Site SARS-CoV-2 Detection.

Cost-effective, rapid, and sensitive detection of SARS-CoV-2, in high-throughput, is crucial in controlling the COVID-19 epidemic. In this study, we proposed a vertical microcavity and localized surface plasmon resonance hybrid biosensor for SARS-CoV-2 detection in artificial saliva and assessed its efficacy. The proposed biosensor monitors the valley shifts in the reflectance spectrum, as induced by changes in the refractive index within the proximity of the sensor surface. A low-cost and fast method was developed to form nanoporous gold (NPG) with different surface morphologies on the vertical microcavity wafer, followed by immobilization with the SARS-CoV-2 antibody for capturing the virus. Modeling and simulation were conducted to optimize the microcavity structure and the NPG parameters. Simulation results revealed that NPG-deposited sensors performed better in resonance quality and in sensitivity compared to gold-deposited and pure microcavity sensors. The experiment confirmed the effect of NPG surface morphology on the biosensor sensitivity as demonstrated by simulation. Pre-clinical validation revealed that 40% porosity led to the highest sensitivity for SARS-CoV-2 pseudovirus at 319 copies/mL in artificial saliva. The proposed automatic biosensing system delivered the results of 100 samples within 30 min, demonstrating its potential for on-site coronavirus detection with sufficient sensitivity.