A lab-on-chip solution for the detection and suppression of COVID-19 severity.

At present, the conventional method for detecting COVID-19 infection is reverse transcription-polymerase chain reaction (RT-PCR) performed on nasopharyngeal and pharyngeal swabs. In addition, other detection techniques such as isothermal nucleic acid amplification, enzyme-linked immunosorbent assay (ELISA) have also been proposed and are being used. However, these techniques are limited to central hospitals and pathologies. Point-of-care solutions may play an important role in rapid and timely detection by an individual at their doorstep. In addition, the disease adversely affects the functioning of various constituents of human blood. For example, it reduces the platelets count, increases production of proinflammatory cytokine which results in cytokine storm, and increases level of various plasma proteins with the severity of the disease. Therefore, monitoring and transfusion of blood plasma and platelets may play an essential role in detection and suppression of severity of COVID-19 infection. In this regard, we propose evolution of our existing microdevice for the detection and suppression of severity of COVID-19 infection. We propose modification of our microdevice in the following ways (i) as a platelet-rich plasma separation unit, (ii) as an on-chip device to study inter-cellular properties of platelets, and (iii) for on-chip detection of infection by separating plasma. The integration of these microdevices with lateral flow assays, flow-virometry reader (FVR), direct serological biosensor assay along with proprietary technology based on plasmonic, place these microdevices in an advantageous position. Moreover, coupling of the microdevices with machine leaning application for rapid detection of the severity of COVID-19 and platelets related disorders makes these microdevices as a complete unit for point-of-care application.

Effectiveness of N95 Mask in Preventing COVID-19 Transmission.

N95 mask has emerged as a potential measure to mitigate the airborne transmission of respiratory disease such as COVID-19. Herein, we experimentally investigated the impact and interaction of pure water droplets as surrogate to respiratory droplets with the different layers of a commercially available N95 mask to demonstrate the penetration and passage-capability of respiratory fluids through the different layers. The penetration of an impacting droplet through the mask layers was characterized by elucidating the ejection of secondary droplets from the rear-side surface of the target mask material. In addition, the passage of respiratory fluids through the mask layers was characterized by capillary imbibition of the droplet liquid through the pores, as a function of wettability of the mask material. Droplet impact at Weber numbers We = 208 and 416 has been considered in the present study; the chosen We range corresponds to that of cough droplets realized in real respiratory events. Each layer of the N95 mask is hydrophobic that prevents capillary imbibition through the pores: a sessile droplet placed over the surface exhibits classical diffusion-limited evaporation. Droplet impact experiments on N95 mask layer surfaces reveal that a single layer allows liquid penetration at We = 416; while a combination of five layers, as is the case of a commercially available N95 mask, blocks the penetration completely, consistent with the widely known effectiveness of N95 masks. Herein, we devote special attention to compare the so-obtained efficiency of N95 masks to that of a recently designed two-layer cloth mask containing an intermediate High-Efficiency Particulate Air (HEPA) filter layer (Narayan et al. in Phys Fluids 34:061703, 2022). We conclusively show that the performance of the designed cloth mask is identical to that of a commercially available N95 mask. The assessment of mask effectiveness further includes examination of breathability and comfort by means of passage of air through them. A comparative study has been presented herein for a clear demonstration of effectiveness of different masks in preventing air-borne transmission of COVID-19.

Improving Indoor Air Ventilation by a Ceiling Fan to Mitigate Aerosols Transmission

Improving air flow and ventilation in an indoor environment is central to mitigating the airborne transmission of aerosols. Examples include, COVID-19 or similar diseases that transmit by airborne aerosols or respiratory droplets. While there are standard guidelines for enhancing the ventilation of space, the effect of a ceiling fan on the ventilation has not been explored. Such an intervention could be critical, especially in a resource-limited setting. In the present work, we numerically study the effect of a rotating ceiling fan on indoor air ventilation using computational fluid dynamics (CFD) simulations. In particular, we employ RANS turbulence model and compare the computed flow fields for a stationary and rotating fan in an office room with a door and window. While a re-circulation zone spans the whole space for the stationary fan, stronger re-circulation zones and small stagnation zones appear in the flow-field inside the room for the case of a rotating fan. The re-circulation zones help bring in fresh air through the window and remove stale air through the door, thereby improving the ventilation rate by one order of magnitude. We briefly discuss the chances of infection by aerosols via flow-fields corresponding to stationary and rotating fans. Graphical

Blood-based biomarkers for diagnosis, prognosis, and severity prediction of COVID-19: Opportunities and challenges.

The reasons for high morbidity and mortality with Corona virus disease (COVID-19) disease remain unanswered with extremes of manifestation and uncertainty of modes of transmission for which biomarkers are urgently needed for early prediction of severity and prompt treatment. We have reviewed publications from PubMed (years 2019-2021) analysing the biochemical, immune-inflammatory, nucleic acid, and cellular biomarkers that predict infection, disease progression in COVID-19 with emphasis on organ-specific damage. Our analysis of 65 biomarkers assessing the impact of SCoV-2 infection on five organs (lung, liver, cardiac, kidney, and neural) reported that increased levels of CRP, TNF-α, ferritin, IL-6, D-dimer, Procalcitonin, Fibrinogen to Albumin Ratio (FAR), and decrease platelet count (PC), lymphocyte count, leukocyte count, and CD4+/CD8 + ratio shows promising association in the early diagnosis, prediction of prognosis and severity disease and also correlates with cytokine storm a cardinal feature of COVID-19 progression. In the above scenario, this review has put forth the most promising biomarkers for COVID diagnosis and prognosis based on the reported literature. In recent year's chemically synthesized antibody-like biomolecules, aptamers were also used in the diagnosis of COVID-19 which could be preferably used for diagnosis over antibodies. Biomarkers including increase in free DNA and Fibrinogen-to-Albumin Ratio, CRP, PCT, and Ferritin along with a consequential decrease of CD3+ T, CD4+ T, CD8+ T, NK cells with corresponding increase in CD4+/CD8+ ratio following SARS CoV-2 infection has been consistently correlated with disease severity. Despite the two waves of COVID-19 pandemic, currently there is no standard clinical practice guideline for evaluating the severity of the devastating pandemic of COVID-19, hence these biomarkers will have immense relevance for the third and subsequent wave of COVID-19 and related pandemic.

Body-mass index COVID-19 severity: A systematic review of systematic reviews.

Objectives: Conflicting studies have resulted in several systematic reviews and meta-analyses on the relationship between COVID-19 and body mass index (BMI). Methods: This systematic review of systematic reviews followed an umbrella review design, and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines; Medical literature analysis and retrieval system online (MEDLINE) and SCOPUS databases were searched for systematic reviews on the topic. A predefined screening and selection procedure was done for the retrieved results based on the population, intervention/interest, comparator, outcome, study (PICOS) framework. Results: The search strategy yielded 6334 citations. With the predefined selection and screening process, 23 systematic reviews were retrieved for inclusion in the present study. Twenty-three (n = 23) systematic reviews met the inclusion criteria. As expected, there was overlap across the reviews in the included primary studies. Available evidence suggests that Class III obesity (morbid obesity) is strongly associated with increased mortality risk in patients with Covid-19. It is difficult to draw a firm conclusion about Class I and Class II obesity due to conflicting outcomes of metanalyses. Increased obesity was consistently associated with increased risk of invasive mechanical ventilation (IMV) in all the reviews with low to moderate heterogeneity. Conclusions: Available evidence suggests that Class III obesity (morbid obesity) is strongly associated with increased mortality risk in patients with Covid-19. Increased BMI is positively associated with the risk of IMV and the severity of COVID- care.

Immunological characteristics of CoVID-19 and its implications

CoVID-19 is the most formidable unequaled global challenge invading 220 countries and territories in this millennium to uncountable saga of mortality, disability as humanity is witnessing devastation of socio-economy with more than 4 million deaths till date. The natural history of CoVID-19 from transmission through varied clinical features to overt complications is still under global research and research groups are on the run to trace its ramifications. This ranges from primary involvement of the pulmonary system to multisystem involvement through web of immunological pathways associated with susceptibility, clinical presentations, and severity of COVID-19. It has been hypothesized that the safe and effective mass vaccination program across the globe can ensure flattening of the pandemic curve to prepandemic normal life. This research group explored the basic and applied researches on molecular and immune mechanisms of SARS COV-2 virus. A sincere attempt has been made in futuristic research vision to find potential strengths, shortfalls, and efficacy of the plant-based immunotherapy, antibodies, and vaccine. Different research groups have hypothesized for the best possible use of these indigenous, stable, secure, efficacious natural products by searching their potential to accomplish emergency demands in this trying time. There is an urgent need to understand the inherent immunological predictors of the natural history of the disease spread over the spectrum from mild to severe forms of the disease and harp on these issues. In the wake of multiple waves with worse situations of evolving clinical features with the "variants of concern" and "variants of interest" and innovative interventions, this research group believes in optimum mix of microbial-derived biologicals with immune modifying drugs will broaden the preventive and curative spectrum. [ FROM AUTHOR] Copyright of Indian Journal of Health Sciences & Biomedical Research is the property of Wolters Kluwer India Pvt Ltd 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.)

COVID-19 pandemic effects on the distribution of healthcare services in India: A systematic review.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has brought fundamental changes to our problems and priorities, especially those related to the healthcare sector. India was one of the countries severely affected by the harsh consequences of the COVID-19 pandemic. AIM: To understand the challenges faced by the healthcare system during a pandemic. METHODS: The literature search for this review was conducted using PubMed, EMBASE, Scopus, Web of Science, and Google Scholar. We also used Reference Citation Analysis (RCA) to search and improve the results. We focused on the published scientific articles concerned with two major vital areas: (1) The Indian healthcare system; and (2) COVID-19 pandemic effects on the Indian healthcare system. RESULTS: The Indian healthcare system was suffering even before the pandemic. The pandemic has further stretched the healthcare services in India. The main obstacle in the healthcare system was to combat the rising number of communicable as well as noncommunicable diseases. Besides the pandemic measures, there was a diversion of focus of the already established healthcare services away from the chronic conditions and vaccinations. The disruption of the vaccination services may have more severe short and long-term consequences than the pandemic's adverse effects. CONCLUSION: Severely restricted resources limited the interaction of the Indian healthcare system with the COVID-19 pandemic. Re-establishment of primary healthcare services, maternal and child health services, noncommunicable diseases programs, National Tuberculosis Elimination Program, etc. are important to prevent serious long-term consequences of this pandemic.

Tailoring surface wettability to reduce chances of infection of COVID-19 by a respiratory droplet and to improve the effectiveness of personal protection equipment Note: This paper is part of the Special Topic, Flow and the Virus

Motivated by the fact that the drying time of respiratory droplets is related to the spread of COVID-19 [R. Bhardwaj and A. Agrawal, “Likelihood of survival of coronavirus in a respiratory droplet deposited on a solid surface,” Phys. Fluids 32, 061704, (2020)], we analyze the drying time of droplets ejected from a COVID-19 infected subject on surfaces of personal protection equipment (PPE), such as a face mask, of different wettabilities. We report the ratio of drying time of the droplet on an ideal superhydrophobic surface (contact angle, θ → 180°) to an ideal hydrophilic surface (θ → 0°) and the ratio of the maximum to minimum drying time of the droplet on the surfaces with different contact angles. The drying time is found to be maximum if θ = 148°, while the aforementioned ratios are 4.6 and 4.8, respectively. These ratios are independent of the droplet initial volume, ambient temperature, relative humidity, and thermophysical properties of the droplet and water vapor. We briefly examine the change in drying time in the presence of impurities on the surface. Besides being of fundamental interest, the analysis provides insights that are useful while designing the PPE to tackle the present pandemic.

A review on coronavirus survival on impermeable and porous surfaces

We review recent studies on fomite transmission of COVID-19, caused by the novel coronavirus. In particular, we focus on survival time of coronavirus on solid and porous surfaces. Since the aqueous phase of a respiratory droplet serves as a medium for virus survival, evaporation of the droplet on a surface plays a crucial role in determining the virus survival time. While the bulk of the droplet takes a few seconds to evaporate, previous virus titer measurements revealed that the virus can survive for several hours or days on a surface. This long survival of virus has been attributed to a residual thin-liquid film which remains after drying of the bulk droplet. The evaporation of the thin-film is governed by the disjoining pressure within it and therefore, is a much slower process which causes the virus to survive longer. However, the aforesaid disjoining pressure is significantly modulated for the case of porous surfaces due to their typical geometries. This accelerates the thin-film evaporation on porous surfaces and thereby making them lesser susceptible to virus survival. Therefore, porous materials are deemed to be relatively safer for mitigating the spread of COVID-19 via fomite transmission. Using results of the reported research, we briefly discuss the possible recommendations to mitigate the spread of the disease.

Evaluating a transparent coating on a face shield for repelling airborne respiratory droplets.

A face shield is an important personal protective equipment to avoid the airborne transmission of COVID-19. We assess a transparent coating on a face shield that repels airborne respiratory droplets to mitigate the spread of COVID-19. The surface of the available face shield is hydrophilic and exhibits high contact angle hysteresis. The impacting droplets stick on it, resulting in an enhanced risk of fomite transmission of the disease. Further, it may get wetted in the rain, and moisture may condense on it in the presence of large humidity, which may blur the user's vision. Therefore, the present study aims to improve the effectiveness of a face shield. Our measurements demonstrate that the face shield, coated by silica nanoparticles solution, becomes superhydrophobic and results in a nominal hysteresis to the underlying surface. We employ high-speed visualization to record the impact dynamics of microliter droplets with a varying impact velocity and angle of attack on coated and non-coated surfaces. While the droplet on non-coated surface sticks to it, in the coated surface the droplets bounce off and roll down the surface, for a wide range of Weber number. We develop an analytical model and present a regime map of the bouncing and non-bouncing events, parametrized with respect to the wettability, hysteresis of the surface, and the Weber number. The present measurements provide the fundamental insights of the bouncing droplet impact dynamics and show that the coated face shield is potentially more effective in suppressing the airborne and fomite transmission.

Effect of co-flow on fluid dynamics of a cough jet with implications in spread of COVID-19.

We discuss the temporal evolution of a cough jet of an infected subject in the context of the spread of COVID-19. Computations were carried out using large eddy simulation, and, in particular, the effect of the co-flow (5% and 10% of maximum cough velocity) on the evolution of the jet was quantified. The Reynolds number (Re) of the cough jet, based on the mouth opening diameter (D) and the average cough velocity, is 13 002. The time-varying inlet velocity profile of the cough jet is represented as a combination of gamma-probability-distribution functions. Simulations reveal the detailed structure of cough jet with and without a co-flow for the first time, to the best of our knowledge. The cough jet temporal evolution is similar to that of a continuous free-jet and follows the same routes of instability, as documented for a free-jet. The convection velocity of the cough jet decays with time and distance, following a power-law variation. The cough jet is observed to travel a distance of approximately 1.1 m in half a second. However, in the presence of 10% co-flow, the cough jet travels faster and covers the similar distance in just 0.33 s. Therefore, in the presence of a co-flow, the probability of transmission of COVID-19 by airborne droplets and droplet nuclei increases, since they can travel a larger distance. The cough jet without the co-flow corresponds to a larger volume content compared to that with the co-flow and spreads more within the same range of distance. These simulations are significant as they help to reveal the intricate structure of the cough jet and show that the presence of a co-flow can significantly augment the risk of infection of COVID-19.

The 2021 Toolkit for Emergency Preparedness and Mitigation to Combat Surge of Pediatric COVID-19 Patients in India: The World Health Organization Collaborating Center for Emergency and Trauma in South East Asia Recommendations.

The authors of this toolkit focus on children under the age of 18 comprising approximately 41% of the total population in India. This toolkit has been created with an objective to prepare, mitigate the effects of any surge of COVID-19 in our communities, and help to optimally utilize the scarce resources. The toolkit design suggests the manpower, equipment, laboratory support, training, consumables, and drugs for a 10-bedded pediatric emergency room, 25-bedded COVID pediatric intensive care unit, and 75-bedded COVID pediatric high dependency unit/ward as defined for a 100-bedded facility. A dedicated and detailed chapter is included to address the psychological needs of the children. These data can be modified for other department sizes based on the facilities, needs, local environment, and resources available.

How coronavirus survives for hours in aerosols.

COVID (CoronaVirus Disease)-19, caused by severe acute respiratory syndrome-CoronaVirus-2 (SARS-CoV-2) virus, predominantly transmits via airborne route, as highlighted by recent studies. Furthermore, recently published titer measurements of SARS-CoV-2 in aerosols have disclosed that the coronavirus can survive for hours. A consolidated knowledge on the physical mechanism and governing rules behind the significantly long survival of coronavirus in aerosols is lacking, which is the subject of the present investigation. We model the evaporation of aerosolized droplets of diameter ≤5 µ m. The conventional diffusion-limited evaporation is not valid to model the evaporation of small size (µm-nm) droplets since it predicts drying time on the order of milliseconds. Also, the sedimentation timescale of desiccated droplets is on the order of days and overpredicts the virus survival time; hence, it does not corroborate with the above-mentioned titer-decay timescale. We attribute the virus survival timescale to the fact that the drying of small ( ∼µ m-nm) droplets is governed, in principle, by the excess internal pressure within the droplet, which stems from the disjoining pressure due to the cohesive intermolecular interaction between the liquid molecules and the Laplace-pressure. The model predictions for the temporal reduction in the aerosolized droplet number density agree well with the temporal decay of virus titer. The findings, therefore, provide insight on the survival of coronavirus in aerosols, which is particularly important to mitigate the spread of COVID-19 from indoors.

Analysis of Second Wave of COVID-19 in Different Countries.

We analyse the evolution of the second wave of the COVID-19 pandemic in several countries by using a logistic model. The model uses a regression analysis based on the least-squares fitting. In particular, the growth rate of the infection has been fitted as an exponential increase, as compared to a power law increase, reported previously in logistic models. The data shows that the increase in the exponent of the exponential increase is around 0.03 day - 1 , with a standard deviation of 0.01  day - 1 . The present results suggest that duration of the peaking of the second wave is almost same for several countries considered. The growth rate is also on the same order of several countries regardless of the total number of infections in a particular country. Since the decay of the growth rate is self-similar to that during the increase in the second wave of several countries, we can predict the end of the second wave in India. The model suggests that the second wave will end in the first week of August 2021, with a growth rate of 0.1% day - 1 at that time.